Related
While updating our build incrementer program that runs during the pre-build event, I noticed a potential problem that can cause quite a bit of issues. Building the application the first time successfully updates BuildInfo.cs and calculates all of the const values. Each subsequent build and successful execution of the pre-build event updates the proper file (as provided below) but each computed const value is out of date from the last build.
// In externally modified file BuildInfo.cs which is updated by our pre-build
// tool to update the version information and produce new consts.
namespace ConstProblem.Properties {
static class BuildInfo {
internal const string AssemblyVersionString = "1.1.0.0";
internal const string BuildDate = "2012-11-07T08:52:32.5480259-07:00";
internal const string FileVersionString = "1.1.12312.852";
internal const string Full = "v1.1 (Build: 2012-11-07 08:52)";
internal const string Short = "1.1";
}
}
// Program.cs. Reproduces the problem for this question.
namespace ConstProblem {
class Program {
const string UserAgent = "ConstProblem/" + Properties.BuildInfo.Short;
static void Main() {
System.Console.WriteLine(UserAgent);
}
}
}
As an example, the application was originally built with the AssemblyVersionString at 1.0.0.0. The above program ran and compiled as expected. Increasing this to 1.1 and building/running the application a second time produced ConstProblem/1.0 as it's output and has this as it's values
// From the Immediate Window
Properties.BuildInfo
ConstProblem.Properties.BuildInfo
base {object}: object
AssemblyVersionString: "1.1.0.0"
BuildDate: "2012-11-07T08:51:46.8404556-07:00"
FileVersionString: "1.0.12312.851"
Full: "v1.0 (Build: 2012-11-07 08:51)"
Short: "1.0"
As you can see, the AssemblyVersionString was updated 1.1.0.0 properly but the rest of the computed values did not. If I were to build and execute a third time (and increase to 1.2) they would update to the information provided above.
I have confirmed that the output file by the pre-build event outputs all of the information correctly and exits with a status of 0 to allow the build to continue. I am at a loss as to why the const's are constantly one build behind. The build utility is also something I wrote and it just uses a template and replaces the contents of the BuildInfo.cs if the file is checked-out.
My environment is running Visual Studio 2010 Ultimate and compiling in .Net 4. I've reproduced this in both Console and Web applications. I got the idea for using const values from the comments in How to get the assembly version and file version of your own assembly?
It's reading the successful build increment from AssemblyInfo.cs
But that only increments by 1 after a successful build, hence why your always 1 behind.
add
[assembly: AssemblyVersion("1.star.star.star")] to AssemblyInfo.cs (in Solution/Properties)
^ star = * (editor limitation)
I currently have an app displaying the build number in its title window. That's well and good except it means nothing to most of the users, who want to know if they have the latest build - they tend to refer to it as "last Thursday's" rather than build 1.0.8.4321.
The plan is to put the build date there instead - So "App built on 21/10/2009" for example.
I'm struggling to find a programmatic way to pull the build date out as a text string for use like this.
For the build number, I used:
Assembly.GetExecutingAssembly().GetName().Version.ToString()
after defining how those came up.
I'd like something like that for the compile date (and time, for bonus points).
Pointers here much appreciated (excuse pun if appropriate), or neater solutions...
Jeff Atwood had a few things to say about this issue in Determining Build Date the hard way.
The most reliable method turns out to be retrieving the linker timestamp from the PE header embedded in the executable file -- some C# code (by Joe Spivey) for that from the comments to Jeff's article:
public static DateTime GetLinkerTime(this Assembly assembly, TimeZoneInfo target = null)
{
var filePath = assembly.Location;
const int c_PeHeaderOffset = 60;
const int c_LinkerTimestampOffset = 8;
var buffer = new byte[2048];
using (var stream = new FileStream(filePath, FileMode.Open, FileAccess.Read))
stream.Read(buffer, 0, 2048);
var offset = BitConverter.ToInt32(buffer, c_PeHeaderOffset);
var secondsSince1970 = BitConverter.ToInt32(buffer, offset + c_LinkerTimestampOffset);
var epoch = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
var linkTimeUtc = epoch.AddSeconds(secondsSince1970);
var tz = target ?? TimeZoneInfo.Local;
var localTime = TimeZoneInfo.ConvertTimeFromUtc(linkTimeUtc, tz);
return localTime;
}
Usage example:
var linkTimeLocal = Assembly.GetExecutingAssembly().GetLinkerTime();
Note: this method works for .NET Core 1.0, but stopped working after .NET Core 1.1 - it gives random years in the 1900-2020 range.
Add below to pre-build event command line:
echo %date% %time% > "$(ProjectDir)\Resources\BuildDate.txt"
Add this file as resource,
now you have 'BuildDate' string in your resources.
To create resources, see How to create and use resources in .NET.
The way
As pointed out by #c00000fd in the comments. Microsoft is changing this. And while many people don't use the latest version of their compiler I suspect this change makes this approach unquestionably bad. And while it's a fun exercise I would recommend people to simply embed a build date into their binary through any other means necessary if it's important to track the build date of the binary itself.
This can be done with some trivial code generation which probably is the first step in your build script already. That, and the fact that ALM/Build/DevOps tools help a lot with this and should be preferred to anything else.
I leave the rest of this answer here for historical purposes only.
The new way
I changed my mind about this, and currently use this trick to get the correct build date.
#region Gets the build date and time (by reading the COFF header)
// http://msdn.microsoft.com/en-us/library/ms680313
struct _IMAGE_FILE_HEADER
{
public ushort Machine;
public ushort NumberOfSections;
public uint TimeDateStamp;
public uint PointerToSymbolTable;
public uint NumberOfSymbols;
public ushort SizeOfOptionalHeader;
public ushort Characteristics;
};
static DateTime GetBuildDateTime(Assembly assembly)
{
var path = assembly.GetName().CodeBase;
if (File.Exists(path))
{
var buffer = new byte[Math.Max(Marshal.SizeOf(typeof(_IMAGE_FILE_HEADER)), 4)];
using (var fileStream = new FileStream(path, FileMode.Open, FileAccess.Read))
{
fileStream.Position = 0x3C;
fileStream.Read(buffer, 0, 4);
fileStream.Position = BitConverter.ToUInt32(buffer, 0); // COFF header offset
fileStream.Read(buffer, 0, 4); // "PE\0\0"
fileStream.Read(buffer, 0, buffer.Length);
}
var pinnedBuffer = GCHandle.Alloc(buffer, GCHandleType.Pinned);
try
{
var coffHeader = (_IMAGE_FILE_HEADER)Marshal.PtrToStructure(pinnedBuffer.AddrOfPinnedObject(), typeof(_IMAGE_FILE_HEADER));
return TimeZone.CurrentTimeZone.ToLocalTime(new DateTime(1970, 1, 1) + new TimeSpan(coffHeader.TimeDateStamp * TimeSpan.TicksPerSecond));
}
finally
{
pinnedBuffer.Free();
}
}
return new DateTime();
}
#endregion
The old way
Well, how do you generate build numbers? Visual Studio (or the C# compiler) actually provides automatic build and revision numbers if you change the AssemblyVersion attribute to e.g. 1.0.*
What will happen is that is that the build will be equal to the number of days since January 1, 2000 local time, and for revision to be equal to the number of seconds since midnight local time, divided by 2.
see Community Content, Automatic Build and Revision numbers
e.g. AssemblyInfo.cs
[assembly: AssemblyVersion("1.0.*")] // important: use wildcard for build and revision numbers!
SampleCode.cs
var version = Assembly.GetEntryAssembly().GetName().Version;
var buildDateTime = new DateTime(2000, 1, 1).Add(new TimeSpan(
TimeSpan.TicksPerDay * version.Build + // days since 1 January 2000
TimeSpan.TicksPerSecond * 2 * version.Revision)); // seconds since midnight, (multiply by 2 to get original)
Add below to pre-build event command line:
echo %date% %time% > "$(ProjectDir)\Resources\BuildDate.txt"
Add this file as resource, now you have 'BuildDate' string in your resources.
After inserting the file into the Resource (as public text file), I accessed it via
string strCompTime = Properties.Resources.BuildDate;
To create resources, see How to create and use resources in .NET.
One approach which I'm amazed no-one has mentioned yet is to use T4 Text Templates for code generation.
<## template debug="false" hostspecific="true" language="C#" #>
<## assembly name="System.Core" #>
<## import namespace="System" #>
<## output extension=".g.cs" #>
using System;
namespace Foo.Bar
{
public static partial class Constants
{
public static DateTime CompilationTimestampUtc { get { return new DateTime(<# Write(DateTime.UtcNow.Ticks.ToString()); #>L, DateTimeKind.Utc); } }
}
}
Pros:
Locale-independent
Allows a lot more than just the time of compilation
Cons:
Only applicable to libraries where you control the source
Requires configuring your project (and build server, if that doesn't pick it up) to execute the template in a pre-build step. (See also T4 without VS).
Lots of great answers here but I feel like I can add my own because of simplicity, performance (comparing to resource-related solutions) cross platform (works with Net Core too) and avoidance of any 3rd party tool. Just add this msbuild target to the csproj.
<Target Name="Date" BeforeTargets="BeforeBuild">
<WriteLinesToFile File="$(IntermediateOutputPath)gen.cs" Lines="static partial class Builtin { public static long CompileTime = $([System.DateTime]::UtcNow.Ticks) %3B }" Overwrite="true" />
<ItemGroup>
<Compile Include="$(IntermediateOutputPath)gen.cs" />
</ItemGroup>
</Target>
and now you have Builtin.CompileTime in this project, e.g.:
var compileTime = new DateTime(Builtin.CompileTime, DateTimeKind.Utc);
ReSharper is not gonna like it. You can ignore him or add a partial class to the project too but it works anyway.
UPD: Nowadays ReSharper have an option in a first page of Options: "MSBuild access", "Obtain data from MSBuild after each compilation". This helps with visibility of generated code.
For .NET Core projects, I adapted Postlagerkarte's answer to update the assembly Copyright field with the build date.
Directly Edit csproj
The following can be added directly to the first PropertyGroup in the csproj:
<Copyright>Copyright © $([System.DateTime]::UtcNow.Year) Travis Troyer ($([System.DateTime]::UtcNow.ToString("s")))</Copyright>
Alternative: Visual Studio Project Properties
Or paste the inner expression directly into the Copyright field in the Package section of the project properties in Visual Studio:
Copyright © $([System.DateTime]::UtcNow.Year) Travis Troyer ($([System.DateTime]::UtcNow.ToString("s")))
This can be a little confusing, because Visual Studio will evaluate the expression and display the current value in the window, but it will also update the project file appropriately behind the scenes.
Solution-wide via Directory.Build.props
You can plop the <Copyright> element above into a Directory.Build.props file in your solution root, and have it automatically applied to all projects within the directory, assuming each project does not supply its own Copyright value.
<Project>
<PropertyGroup>
<Copyright>Copyright © $([System.DateTime]::UtcNow.Year) Travis Troyer ($([System.DateTime]::UtcNow.ToString("s")))</Copyright>
</PropertyGroup>
</Project>
Directory.Build.props: Customize your build
Output
The example expression will give you a copyright like this:
Copyright © 2018 Travis Troyer (2018-05-30T14:46:23)
Retrieval
You can view the copyright information from the file properties in Windows, or grab it at runtime:
var version = FileVersionInfo.GetVersionInfo(Assembly.GetEntryAssembly().Location);
Console.WriteLine(version.LegalCopyright);
Regarding the technique of pulling build date/version info from the bytes of an assembly PE header, Microsoft has changed the default build parameters beginning with Visual Studio 15.4. The new default includes deterministic compilation, which makes a valid timestamp and automatically incremented version numbers a thing of the past. The timestamp field is still present but it gets filled with a permanent value that is a hash of something or other, but not any indication of the build time.
Some detailed background here
For those who prioritize a useful timestamp over deterministic compilation, there is a way to override the new default. You can include a tag in the .csproj file of the assembly of interest as follows:
<PropertyGroup>
...
<Deterministic>false</Deterministic>
</PropertyGroup>
Update:
I endorse the T4 text template solution described in another answer here. I used it to solve my issue cleanly without losing the benefit of deterministic compilation. One caution about it is that Visual Studio only runs the T4 compiler when the .tt file is saved, not at build time. This can be awkward if you exclude the .cs result from source control (since you expect it to be generated) and another developer checks out the code. Without resaving, they won't have the .cs file. There is a package on nuget (I think called AutoT4) that makes T4 compilation part of every build. I have not yet confronted the solution to this during production deployment, but I expect something similar to make it right.
I am just C# newbie so maybe my answer sound silly - I display the build date from the date the executable file was last written to:
string w_file = "MyProgram.exe";
string w_directory = Directory.GetCurrentDirectory();
DateTime c3 = File.GetLastWriteTime(System.IO.Path.Combine(w_directory, w_file));
RTB_info.AppendText("Program created at: " + c3.ToString());
I tried to use File.GetCreationTime method but got weird results: the date from the command was 2012-05-29, but the date from the Window Explorer showed 2012-05-23. After searching for this discrepancy I found that the file was probably created on 2012-05-23 (as shown by Windows Explorer), but copied to the current folder on 2012-05-29 (as shown by File.GetCreationTime command) - so to be on the safe side I am using File.GetLastWriteTime command.
Zalek
In 2018 some of the above solutions do not work anymore or do not work with .NET Core.
I use the following approach which is simple and works for my .NET Core 2.0 project.
Add the following to your .csproj inside the PropertyGroup :
<Today>$([System.DateTime]::Now)</Today>
This defines a PropertyFunction which you can access in your pre build command.
Your pre-build looks like this
echo $(today) > $(ProjectDir)BuildTimeStamp.txt
Set the property of the BuildTimeStamp.txt to Embedded resource.
Now you can read the time stamp like this
public static class BuildTimeStamp
{
public static string GetTimestamp()
{
var assembly = Assembly.GetEntryAssembly();
var stream = assembly.GetManifestResourceStream("NamespaceGoesHere.BuildTimeStamp.txt");
using (var reader = new StreamReader(stream))
{
return reader.ReadToEnd();
}
}
}
I just do:
File.GetCreationTime(GetType().Assembly.Location)
The above method can be tweaked for assemblies already loaded within the process by using the file's image in memory (as opposed to re-reading it from storage):
using System;
using System.Runtime.InteropServices;
using Assembly = System.Reflection.Assembly;
static class Utils
{
public static DateTime GetLinkerDateTime(this Assembly assembly, TimeZoneInfo tzi = null)
{
// Constants related to the Windows PE file format.
const int PE_HEADER_OFFSET = 60;
const int LINKER_TIMESTAMP_OFFSET = 8;
// Discover the base memory address where our assembly is loaded
var entryModule = assembly.ManifestModule;
var hMod = Marshal.GetHINSTANCE(entryModule);
if (hMod == IntPtr.Zero - 1) throw new Exception("Failed to get HINSTANCE.");
// Read the linker timestamp
var offset = Marshal.ReadInt32(hMod, PE_HEADER_OFFSET);
var secondsSince1970 = Marshal.ReadInt32(hMod, offset + LINKER_TIMESTAMP_OFFSET);
// Convert the timestamp to a DateTime
var epoch = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
var linkTimeUtc = epoch.AddSeconds(secondsSince1970);
var dt = TimeZoneInfo.ConvertTimeFromUtc(linkTimeUtc, tzi ?? TimeZoneInfo.Local);
return dt;
}
}
For projects on .NET Core (.NET 5+), it can be done like this. Nice in that there are no files to add or embed, no T4, and no pre-build scripts.
Add a class like this to your project:
namespace SuperDuper
{
[AttributeUsage(AttributeTargets.Assembly)]
public class BuildDateTimeAttribute : Attribute
{
public string Date { get; set; }
public BuildDateTimeAttribute(string date)
{
Date = date;
}
}
}
Update the .csproj of your project to include something like this:
<ItemGroup>
<AssemblyAttribute Include="SuperDuper.BuildDateTime">
<_Parameter1>$([System.DateTime]::Now.ToString("s"))</_Parameter1>
</AssemblyAttribute>
</ItemGroup>
Note that _Parameter1 is a magical name - it means the first (and only) argument to the constructor of our BuildDateTime attribute class.
That's all that is needed to record the build datetime in your assembly.
And then to read the build datetime of your assembly, do something like this:
private static DateTime? getAssemblyBuildDateTime()
{
var assembly = System.Reflection.Assembly.GetExecutingAssembly();
var attr = Attribute.GetCustomAttribute(assembly, typeof(BuildDateTimeAttribute)) as BuildDateTimeAttribute;
if (DateTime.TryParse(attr?.Date, out DateTime dt))
return dt;
else
return null;
}
Note 1 (per Flydog57 in the comments): If your .csproj has property GenerateAssemblyInfo listed in it and set to false, the build won't generate assembly info and you'll get no BuildDateTime info in your assembly. So either do not mention GenerateAssemblyInfo in your .csproj (this is the default behaviour for a new project, and GenerateAssemblyInfo defaults to true if not specifically set to false), or explicitly set it to true.
Note 2 (per Teddy in the comments): In the _Parameter1 example given, we're using ::Now to make use of DateTime.Now, which is the local date and time on your computer, subject to Daylight Savings Time when applicable and your local timezone. You could if you want use ::UtcNow to make use of DateTime.UtcNow so that the build date and time is recorded as UTC/GMT.
For anyone that needs to get the compile time in Windows 8 / Windows Phone 8:
public static async Task<DateTimeOffset?> RetrieveLinkerTimestamp(Assembly assembly)
{
var pkg = Windows.ApplicationModel.Package.Current;
if (null == pkg)
{
return null;
}
var assemblyFile = await pkg.InstalledLocation.GetFileAsync(assembly.ManifestModule.Name);
if (null == assemblyFile)
{
return null;
}
using (var stream = await assemblyFile.OpenSequentialReadAsync())
{
using (var reader = new DataReader(stream))
{
const int PeHeaderOffset = 60;
const int LinkerTimestampOffset = 8;
//read first 2048 bytes from the assembly file.
byte[] b = new byte[2048];
await reader.LoadAsync((uint)b.Length);
reader.ReadBytes(b);
reader.DetachStream();
//get the pe header offset
int i = System.BitConverter.ToInt32(b, PeHeaderOffset);
//read the linker timestamp from the PE header
int secondsSince1970 = System.BitConverter.ToInt32(b, i + LinkerTimestampOffset);
var dt = new DateTimeOffset(1970, 1, 1, 0, 0, 0, DateTimeOffset.Now.Offset) + DateTimeOffset.Now.Offset;
return dt.AddSeconds(secondsSince1970);
}
}
}
For anyone that needs to get the compile time in Windows Phone 7:
public static async Task<DateTimeOffset?> RetrieveLinkerTimestampAsync(Assembly assembly)
{
const int PeHeaderOffset = 60;
const int LinkerTimestampOffset = 8;
byte[] b = new byte[2048];
try
{
var rs = Application.GetResourceStream(new Uri(assembly.ManifestModule.Name, UriKind.Relative));
using (var s = rs.Stream)
{
var asyncResult = s.BeginRead(b, 0, b.Length, null, null);
int bytesRead = await Task.Factory.FromAsync<int>(asyncResult, s.EndRead);
}
}
catch (System.IO.IOException)
{
return null;
}
int i = System.BitConverter.ToInt32(b, PeHeaderOffset);
int secondsSince1970 = System.BitConverter.ToInt32(b, i + LinkerTimestampOffset);
var dt = new DateTimeOffset(1970, 1, 1, 0, 0, 0, DateTimeOffset.Now.Offset) + DateTimeOffset.Now.Offset;
dt = dt.AddSeconds(secondsSince1970);
return dt;
}
NOTE: In all cases you're running in a sandbox, so you'll only be able to get the compile time of assemblies that you deploy with your app. (i.e. this won't work on anything in the GAC).
The option not discussed here is to insert your own data into AssemblyInfo.cs, the "AssemblyInformationalVersion" field seems appropriate - we have a couple of projects where we were doing something similar as a build step (however I'm not entirely happy with the way that works so don't really want to reproduce what we've got).
There's an article on the subject on codeproject: http://www.codeproject.com/KB/dotnet/Customizing_csproj_files.aspx
I needed a universal solution that worked with a NETStandard project on any platform (iOS, Android, and Windows.) To accomplish this, I decided to automatically generate a CS file via a PowerShell script. Here is the PowerShell script:
param($outputFile="BuildDate.cs")
$buildDate = Get-Date -date (Get-Date).ToUniversalTime() -Format o
$class =
"using System;
using System.Globalization;
namespace MyNamespace
{
public static class BuildDate
{
public const string BuildDateString = `"$buildDate`";
public static readonly DateTime BuildDateUtc = DateTime.Parse(BuildDateString, null, DateTimeStyles.AssumeUniversal | DateTimeStyles.AdjustToUniversal);
}
}"
Set-Content -Path $outputFile -Value $class
Save the PowerScript file as GenBuildDate.ps1 and add it your project. Finally, add the following line to your Pre-Build event:
powershell -File $(ProjectDir)GenBuildDate.ps1 -outputFile $(ProjectDir)BuildDate.cs
Make sure BuildDate.cs is included in your project. Works like a champ on any OS!
A different, PCL-friendly approach would be to use an MSBuild inline task to substitute the build time into a string that is returned by a property on the app. We are using this approach successfully in an app that has Xamarin.Forms, Xamarin.Android, and Xamarin.iOS projects.
EDIT:
Simplified by moving all of the logic into the SetBuildDate.targets file, and using Regex instead of simple string replace so that the file can be modified by each build without a "reset".
The MSBuild inline task definition (saved in a SetBuildDate.targets file local to the Xamarin.Forms project for this example):
<Project xmlns='http://schemas.microsoft.com/developer/msbuild/2003' ToolsVersion="12.0">
<UsingTask TaskName="SetBuildDate" TaskFactory="CodeTaskFactory"
AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.v12.0.dll">
<ParameterGroup>
<FilePath ParameterType="System.String" Required="true" />
</ParameterGroup>
<Task>
<Code Type="Fragment" Language="cs"><![CDATA[
DateTime now = DateTime.UtcNow;
string buildDate = now.ToString("F");
string replacement = string.Format("BuildDate => \"{0}\"", buildDate);
string pattern = #"BuildDate => ""([^""]*)""";
string content = File.ReadAllText(FilePath);
System.Text.RegularExpressions.Regex rgx = new System.Text.RegularExpressions.Regex(pattern);
content = rgx.Replace(content, replacement);
File.WriteAllText(FilePath, content);
File.SetLastWriteTimeUtc(FilePath, now);
]]></Code>
</Task>
</UsingTask>
</Project>
Invoking the above inline task in the Xamarin.Forms csproj file in target BeforeBuild:
<!-- To modify your build process, add your task inside one of the targets below and uncomment it.
Other similar extension points exist, see Microsoft.Common.targets. -->
<Import Project="SetBuildDate.targets" />
<Target Name="BeforeBuild">
<SetBuildDate FilePath="$(MSBuildProjectDirectory)\BuildMetadata.cs" />
</Target>
The FilePath property is set to a BuildMetadata.cs file in the Xamarin.Forms project that contains a simple class with a string property BuildDate, into which the build time will be substituted:
public class BuildMetadata
{
public static string BuildDate => "This can be any arbitrary string";
}
Add this file BuildMetadata.cs to project. It will be modified by every build, but in a manner that allows repeated builds (repeated replacements), so you may include or omit it in source control as desired.
You can use this project: https://github.com/dwcullop/BuildInfo
It leverages T4 to automate the build date timestamp. There are several versions (different branches) including one that gives you the Git Hash of the currently checked out branch, if you're into that sort of thing.
Disclosure: I wrote the module.
You could use a project post-build event to write a text file to your target directory with the current datetime. You could then read the value at run-time. It's a little hacky, but it should work.
I'm not sure, but maybe the Build Incrementer helps.
A small update on the "New Way" answer from Jhon.
You need to build the path instead of using the CodeBase string when working with ASP.NET/MVC
var codeBase = assembly.GetName().CodeBase;
UriBuilder uri = new UriBuilder(codeBase);
string path = Uri.UnescapeDataString(uri.Path);
You could launch an extra step in the build process that writes a date stamp to a file which can then be displayed.
On the projects properties tab look at the build events tab. There is an option to execute a pre or post build command.
I used Abdurrahim's suggestion. However, it seemed to give a weird time format and also added the abbreviation for the day as part of the build date; example: Sun 12/24/2017 13:21:05.43. I only needed just the date so I had to eliminate the rest using substring.
After adding the echo %date% %time% > "$(ProjectDir)\Resources\BuildDate.txt"to the pre-build event, I just did the following:
string strBuildDate = YourNamespace.Properties.Resources.BuildDate;
string strTrimBuildDate = strBuildDate.Substring(4).Remove(10);
The good news here is that it worked.
A full solution step by step for Visual Studio 2019, like the one I wish I had found when I began years ago.
Add a text resource file
Access the properties of your project: from the solution explorer, select your project, then right-click -> properties, or Alt+Enter. In the Resources tab, choose Files (Ctrl+5). Then Add Resource / Add New Text File. In the popup message, type the name of your resource, for example BuildDate: this will create a new text file BuildDate.txt in your Project/Resources folder, include it as Project file, and register it as a resource, which can then be accessed via Properties.Resources in C#, or My.Resources in VB.
Automatically update the resource file each time you build
Now you can tell Visual Studio to write a date into this file, each time it builds or rebuilds the project. For this, go to the Compile tab of the Project Properties, choose Build Events, and copy/paste the following into the "Pre-Build event command line" textbox:
powershell -Command "((Get-Date).ToUniversalTime()).ToString(\"s\") | Out-File '$(ProjectDir)Resources\BuildDate.txt'"
This line will locate BuildDate.txt and write today/NowUtc's date and time under the ISO8601 format, such as 2021-09-07T16:08:35
Obtain the build date at run-time by reading the file
You can then retrieve this date from your code at run-time, via the following helper (C#):
DateTime CurrentBuildDate = DateTime.Parse(Properties.Resources.BuildDate, null, System.Globalization.DateTimeStyles.RoundtripKind);
Credits
Base idea: https://stackoverflow.com/a/15502932/10794555
Improved through powershell by: https://stackoverflow.com/users/84898/dbruning
Stable parsing of ISO8601: How to create a .NET DateTime from ISO 8601 format
GetLastWriteTime isn't changed if you copy the assembly to another location.
public static class AssemblyExtensions
{
public static DateTime GetLinkerTime(this Assembly assembly)
{
return File.GetLastWriteTime(assembly.Location).ToLocalTime();
}
}
If this is a windows app, you can just use the application executable path:
new System.IO.FileInfo(Application.ExecutablePath).LastWriteTime.ToString("yyyy.MM.dd")
I just added pre-build event command:
powershell -Command Get-Date -Format 'yyyy-MM-ddTHH:mm:sszzz' > Resources\BuildDateTime.txt
in the project properties to generate a resource file that is then easy to read from the code.
I had difficulties with the suggested solutions with my project, a .Net Core 2.1 web application. I combined various suggestions from above and simplified, and also converted the date to my required format.
The echo command:
echo Build %DATE:~-4%/%DATE:~-10,2%/%DATE:~-7,2% %time% > "$(ProjectDir)\BuildDate.txt"
The code:
Logger.Info(File.ReadAllText(#"./BuildDate.txt").Trim());
It seems to work. The output:
2021-03-25 18:41:40,877 [1] INFO Config - Build 2021/03/25 18:41:37.58
Nothing very original, I just combined suggestions from here and other related questions, and simplified.
For .NET 5 I've used this method successfully. (Found here).
Add this to the .csproj file:
<SourceRevisionId>build$([System.DateTime]::UtcNow.ToString("yyyyMMddHHmmss"))</SourceRevisionId>
Method for getting build date:
private static DateTime GetBuildDate(Assembly assembly)
{
const string BuildVersionMetadataPrefix = "+build";
var attribute = assembly.GetCustomAttribute<AssemblyInformationalVersionAttribute>();
if (attribute?.InformationalVersion != null)
{
var value = attribute.InformationalVersion;
var index = value.IndexOf(BuildVersionMetadataPrefix);
if (index > 0)
{
value = value.Substring(index + BuildVersionMetadataPrefix.Length);
if (DateTime.TryParseExact(value, "yyyyMMddHHmmss", CultureInfo.InvariantCulture, DateTimeStyles.None, out var result))
{
return result;
}
}
}
return default;
}
Usage:
var buildTime = GetBuildDate(Assembly.GetExecutingAssembly());
buildTime = buildTime.ToLocalTime();
Use the following code.
File.GetCreationTime(Assembly.GetExecutingAssembly().Location)
It will return the date of creation of last dll. If debug is running, then it will display current date and time. I modified some code from one of the answers, because i couldn't comment on the answer. Comment for further discussions.
I'm trying to extract the version number from a AssemblyInfo.cs file!
And I'm trying to use System.Reflection.Assembly.LoadFile(path); But while doing this I get a BadImageFormatException; "The module was expected to contain an assembly manifest. (Exception from HRESULT: 0x80131018)". So now I wounder, is that not a possible way to go about it? And should I use RegEx instead?
I have read many examples with GetExecutingAssembly() but I do want to get the version from an other project.
Clarification: I want to read the version info from the AssemblyInfo.cs file! And not from a compiled file. I'm trying to make a tool to update my version numbers before I make a new release.
You can get Assembly version without loading it as:
using System.Reflection;
using System.IO;
...
// Get assembly
AssemblyName currentAssembly = AssemblyName.GetAssemblyName(path);
Version assemblyVersion = currentAssembly.Version;
Edit:
If you want to read file then you can do it like this:
string path = #"d:\AssemblyInfo.cs";
if (File.Exists(path))
{
// Open the file to read from.
string[] readText = File.ReadAllLines(path);
var versionInfoLines = readText.Where(t => t.Contains("[assembly: AssemblyVersion"));
foreach (string item in versionInfoLines)
{
string version = item.Substring(item.IndexOf('(') + 2, item.LastIndexOf(')') - item.IndexOf('(') - 3);
//Console.WriteLine(Regex.Replace(version, #"\P{S}", string.Empty));
Console.WriteLine(version);
}
}
//Output
1.0.*
1.0.0.0
Hope this help...
You can specify the target assembly path in AssemblyName.GetAssemblyName
AssemblyName.GetAssemblyName("ProjectB.exe").Version
AssemblyInfo.cs file gets compiled to IL assembly.
If you load that assembly you can read the version with all the examples that you have already seen. Which is reading an embedded version information from a compiled assembly file, and it may be overwritten by compilation process to a value different from what is in AssemblyInfo.cs
However it sounds like what you want instead is to read a version number from AssemblyInfo.cs text file, without compiling it down.
If this is the case you really just have to use regex with a format appropriate for your project, or even come up with a convention that will keep it simple.
This could be as simple as
var versionMatch = Regex.Match(File.ReadAllText(filename), #"AssemblyVersion\s*\(\s*""([0-9\.\*]*?)""\s*\)");
if (versionMatch.Success)
{
Console.WriteLine(versionMatch.Groups[1].Value);
}
You would have to consider convention around what goes there, since 1.0.* is a valid version string that translates to timestamp values of form 1.0.nnn.mmm at compile time, and nnn and mmm part closely guessable but not precisely guessable.
It sounds like you're trying to load an assembly compiled for x86 in an x64 environment or vice-versa.
Ensure the assembly this code resides in is built for the same environment as the target and you can get it with the examples it sounds like you've read.
You can proceed with Assembly.GetName().Version where your assembly could be the type of your class
public class Test
{
public static void Main()
{
Console.WriteLine("Current assembly : " + typeof(Test).Assembly.GetName().Version);
}
}
For the test application I have working on, shows me below details using above code:
I currently have an app displaying the build number in its title window. That's well and good except it means nothing to most of the users, who want to know if they have the latest build - they tend to refer to it as "last Thursday's" rather than build 1.0.8.4321.
The plan is to put the build date there instead - So "App built on 21/10/2009" for example.
I'm struggling to find a programmatic way to pull the build date out as a text string for use like this.
For the build number, I used:
Assembly.GetExecutingAssembly().GetName().Version.ToString()
after defining how those came up.
I'd like something like that for the compile date (and time, for bonus points).
Pointers here much appreciated (excuse pun if appropriate), or neater solutions...
Jeff Atwood had a few things to say about this issue in Determining Build Date the hard way.
The most reliable method turns out to be retrieving the linker timestamp from the PE header embedded in the executable file -- some C# code (by Joe Spivey) for that from the comments to Jeff's article:
public static DateTime GetLinkerTime(this Assembly assembly, TimeZoneInfo target = null)
{
var filePath = assembly.Location;
const int c_PeHeaderOffset = 60;
const int c_LinkerTimestampOffset = 8;
var buffer = new byte[2048];
using (var stream = new FileStream(filePath, FileMode.Open, FileAccess.Read))
stream.Read(buffer, 0, 2048);
var offset = BitConverter.ToInt32(buffer, c_PeHeaderOffset);
var secondsSince1970 = BitConverter.ToInt32(buffer, offset + c_LinkerTimestampOffset);
var epoch = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
var linkTimeUtc = epoch.AddSeconds(secondsSince1970);
var tz = target ?? TimeZoneInfo.Local;
var localTime = TimeZoneInfo.ConvertTimeFromUtc(linkTimeUtc, tz);
return localTime;
}
Usage example:
var linkTimeLocal = Assembly.GetExecutingAssembly().GetLinkerTime();
Note: this method works for .NET Core 1.0, but stopped working after .NET Core 1.1 - it gives random years in the 1900-2020 range.
Add below to pre-build event command line:
echo %date% %time% > "$(ProjectDir)\Resources\BuildDate.txt"
Add this file as resource,
now you have 'BuildDate' string in your resources.
To create resources, see How to create and use resources in .NET.
The way
As pointed out by #c00000fd in the comments. Microsoft is changing this. And while many people don't use the latest version of their compiler I suspect this change makes this approach unquestionably bad. And while it's a fun exercise I would recommend people to simply embed a build date into their binary through any other means necessary if it's important to track the build date of the binary itself.
This can be done with some trivial code generation which probably is the first step in your build script already. That, and the fact that ALM/Build/DevOps tools help a lot with this and should be preferred to anything else.
I leave the rest of this answer here for historical purposes only.
The new way
I changed my mind about this, and currently use this trick to get the correct build date.
#region Gets the build date and time (by reading the COFF header)
// http://msdn.microsoft.com/en-us/library/ms680313
struct _IMAGE_FILE_HEADER
{
public ushort Machine;
public ushort NumberOfSections;
public uint TimeDateStamp;
public uint PointerToSymbolTable;
public uint NumberOfSymbols;
public ushort SizeOfOptionalHeader;
public ushort Characteristics;
};
static DateTime GetBuildDateTime(Assembly assembly)
{
var path = assembly.GetName().CodeBase;
if (File.Exists(path))
{
var buffer = new byte[Math.Max(Marshal.SizeOf(typeof(_IMAGE_FILE_HEADER)), 4)];
using (var fileStream = new FileStream(path, FileMode.Open, FileAccess.Read))
{
fileStream.Position = 0x3C;
fileStream.Read(buffer, 0, 4);
fileStream.Position = BitConverter.ToUInt32(buffer, 0); // COFF header offset
fileStream.Read(buffer, 0, 4); // "PE\0\0"
fileStream.Read(buffer, 0, buffer.Length);
}
var pinnedBuffer = GCHandle.Alloc(buffer, GCHandleType.Pinned);
try
{
var coffHeader = (_IMAGE_FILE_HEADER)Marshal.PtrToStructure(pinnedBuffer.AddrOfPinnedObject(), typeof(_IMAGE_FILE_HEADER));
return TimeZone.CurrentTimeZone.ToLocalTime(new DateTime(1970, 1, 1) + new TimeSpan(coffHeader.TimeDateStamp * TimeSpan.TicksPerSecond));
}
finally
{
pinnedBuffer.Free();
}
}
return new DateTime();
}
#endregion
The old way
Well, how do you generate build numbers? Visual Studio (or the C# compiler) actually provides automatic build and revision numbers if you change the AssemblyVersion attribute to e.g. 1.0.*
What will happen is that is that the build will be equal to the number of days since January 1, 2000 local time, and for revision to be equal to the number of seconds since midnight local time, divided by 2.
see Community Content, Automatic Build and Revision numbers
e.g. AssemblyInfo.cs
[assembly: AssemblyVersion("1.0.*")] // important: use wildcard for build and revision numbers!
SampleCode.cs
var version = Assembly.GetEntryAssembly().GetName().Version;
var buildDateTime = new DateTime(2000, 1, 1).Add(new TimeSpan(
TimeSpan.TicksPerDay * version.Build + // days since 1 January 2000
TimeSpan.TicksPerSecond * 2 * version.Revision)); // seconds since midnight, (multiply by 2 to get original)
Add below to pre-build event command line:
echo %date% %time% > "$(ProjectDir)\Resources\BuildDate.txt"
Add this file as resource, now you have 'BuildDate' string in your resources.
After inserting the file into the Resource (as public text file), I accessed it via
string strCompTime = Properties.Resources.BuildDate;
To create resources, see How to create and use resources in .NET.
One approach which I'm amazed no-one has mentioned yet is to use T4 Text Templates for code generation.
<## template debug="false" hostspecific="true" language="C#" #>
<## assembly name="System.Core" #>
<## import namespace="System" #>
<## output extension=".g.cs" #>
using System;
namespace Foo.Bar
{
public static partial class Constants
{
public static DateTime CompilationTimestampUtc { get { return new DateTime(<# Write(DateTime.UtcNow.Ticks.ToString()); #>L, DateTimeKind.Utc); } }
}
}
Pros:
Locale-independent
Allows a lot more than just the time of compilation
Cons:
Only applicable to libraries where you control the source
Requires configuring your project (and build server, if that doesn't pick it up) to execute the template in a pre-build step. (See also T4 without VS).
Lots of great answers here but I feel like I can add my own because of simplicity, performance (comparing to resource-related solutions) cross platform (works with Net Core too) and avoidance of any 3rd party tool. Just add this msbuild target to the csproj.
<Target Name="Date" BeforeTargets="BeforeBuild">
<WriteLinesToFile File="$(IntermediateOutputPath)gen.cs" Lines="static partial class Builtin { public static long CompileTime = $([System.DateTime]::UtcNow.Ticks) %3B }" Overwrite="true" />
<ItemGroup>
<Compile Include="$(IntermediateOutputPath)gen.cs" />
</ItemGroup>
</Target>
and now you have Builtin.CompileTime in this project, e.g.:
var compileTime = new DateTime(Builtin.CompileTime, DateTimeKind.Utc);
ReSharper is not gonna like it. You can ignore him or add a partial class to the project too but it works anyway.
UPD: Nowadays ReSharper have an option in a first page of Options: "MSBuild access", "Obtain data from MSBuild after each compilation". This helps with visibility of generated code.
For .NET Core projects, I adapted Postlagerkarte's answer to update the assembly Copyright field with the build date.
Directly Edit csproj
The following can be added directly to the first PropertyGroup in the csproj:
<Copyright>Copyright © $([System.DateTime]::UtcNow.Year) Travis Troyer ($([System.DateTime]::UtcNow.ToString("s")))</Copyright>
Alternative: Visual Studio Project Properties
Or paste the inner expression directly into the Copyright field in the Package section of the project properties in Visual Studio:
Copyright © $([System.DateTime]::UtcNow.Year) Travis Troyer ($([System.DateTime]::UtcNow.ToString("s")))
This can be a little confusing, because Visual Studio will evaluate the expression and display the current value in the window, but it will also update the project file appropriately behind the scenes.
Solution-wide via Directory.Build.props
You can plop the <Copyright> element above into a Directory.Build.props file in your solution root, and have it automatically applied to all projects within the directory, assuming each project does not supply its own Copyright value.
<Project>
<PropertyGroup>
<Copyright>Copyright © $([System.DateTime]::UtcNow.Year) Travis Troyer ($([System.DateTime]::UtcNow.ToString("s")))</Copyright>
</PropertyGroup>
</Project>
Directory.Build.props: Customize your build
Output
The example expression will give you a copyright like this:
Copyright © 2018 Travis Troyer (2018-05-30T14:46:23)
Retrieval
You can view the copyright information from the file properties in Windows, or grab it at runtime:
var version = FileVersionInfo.GetVersionInfo(Assembly.GetEntryAssembly().Location);
Console.WriteLine(version.LegalCopyright);
Regarding the technique of pulling build date/version info from the bytes of an assembly PE header, Microsoft has changed the default build parameters beginning with Visual Studio 15.4. The new default includes deterministic compilation, which makes a valid timestamp and automatically incremented version numbers a thing of the past. The timestamp field is still present but it gets filled with a permanent value that is a hash of something or other, but not any indication of the build time.
Some detailed background here
For those who prioritize a useful timestamp over deterministic compilation, there is a way to override the new default. You can include a tag in the .csproj file of the assembly of interest as follows:
<PropertyGroup>
...
<Deterministic>false</Deterministic>
</PropertyGroup>
Update:
I endorse the T4 text template solution described in another answer here. I used it to solve my issue cleanly without losing the benefit of deterministic compilation. One caution about it is that Visual Studio only runs the T4 compiler when the .tt file is saved, not at build time. This can be awkward if you exclude the .cs result from source control (since you expect it to be generated) and another developer checks out the code. Without resaving, they won't have the .cs file. There is a package on nuget (I think called AutoT4) that makes T4 compilation part of every build. I have not yet confronted the solution to this during production deployment, but I expect something similar to make it right.
I am just C# newbie so maybe my answer sound silly - I display the build date from the date the executable file was last written to:
string w_file = "MyProgram.exe";
string w_directory = Directory.GetCurrentDirectory();
DateTime c3 = File.GetLastWriteTime(System.IO.Path.Combine(w_directory, w_file));
RTB_info.AppendText("Program created at: " + c3.ToString());
I tried to use File.GetCreationTime method but got weird results: the date from the command was 2012-05-29, but the date from the Window Explorer showed 2012-05-23. After searching for this discrepancy I found that the file was probably created on 2012-05-23 (as shown by Windows Explorer), but copied to the current folder on 2012-05-29 (as shown by File.GetCreationTime command) - so to be on the safe side I am using File.GetLastWriteTime command.
Zalek
In 2018 some of the above solutions do not work anymore or do not work with .NET Core.
I use the following approach which is simple and works for my .NET Core 2.0 project.
Add the following to your .csproj inside the PropertyGroup :
<Today>$([System.DateTime]::Now)</Today>
This defines a PropertyFunction which you can access in your pre build command.
Your pre-build looks like this
echo $(today) > $(ProjectDir)BuildTimeStamp.txt
Set the property of the BuildTimeStamp.txt to Embedded resource.
Now you can read the time stamp like this
public static class BuildTimeStamp
{
public static string GetTimestamp()
{
var assembly = Assembly.GetEntryAssembly();
var stream = assembly.GetManifestResourceStream("NamespaceGoesHere.BuildTimeStamp.txt");
using (var reader = new StreamReader(stream))
{
return reader.ReadToEnd();
}
}
}
I just do:
File.GetCreationTime(GetType().Assembly.Location)
The above method can be tweaked for assemblies already loaded within the process by using the file's image in memory (as opposed to re-reading it from storage):
using System;
using System.Runtime.InteropServices;
using Assembly = System.Reflection.Assembly;
static class Utils
{
public static DateTime GetLinkerDateTime(this Assembly assembly, TimeZoneInfo tzi = null)
{
// Constants related to the Windows PE file format.
const int PE_HEADER_OFFSET = 60;
const int LINKER_TIMESTAMP_OFFSET = 8;
// Discover the base memory address where our assembly is loaded
var entryModule = assembly.ManifestModule;
var hMod = Marshal.GetHINSTANCE(entryModule);
if (hMod == IntPtr.Zero - 1) throw new Exception("Failed to get HINSTANCE.");
// Read the linker timestamp
var offset = Marshal.ReadInt32(hMod, PE_HEADER_OFFSET);
var secondsSince1970 = Marshal.ReadInt32(hMod, offset + LINKER_TIMESTAMP_OFFSET);
// Convert the timestamp to a DateTime
var epoch = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
var linkTimeUtc = epoch.AddSeconds(secondsSince1970);
var dt = TimeZoneInfo.ConvertTimeFromUtc(linkTimeUtc, tzi ?? TimeZoneInfo.Local);
return dt;
}
}
For projects on .NET Core (.NET 5+), it can be done like this. Nice in that there are no files to add or embed, no T4, and no pre-build scripts.
Add a class like this to your project:
namespace SuperDuper
{
[AttributeUsage(AttributeTargets.Assembly)]
public class BuildDateTimeAttribute : Attribute
{
public string Date { get; set; }
public BuildDateTimeAttribute(string date)
{
Date = date;
}
}
}
Update the .csproj of your project to include something like this:
<ItemGroup>
<AssemblyAttribute Include="SuperDuper.BuildDateTime">
<_Parameter1>$([System.DateTime]::Now.ToString("s"))</_Parameter1>
</AssemblyAttribute>
</ItemGroup>
Note that _Parameter1 is a magical name - it means the first (and only) argument to the constructor of our BuildDateTime attribute class.
That's all that is needed to record the build datetime in your assembly.
And then to read the build datetime of your assembly, do something like this:
private static DateTime? getAssemblyBuildDateTime()
{
var assembly = System.Reflection.Assembly.GetExecutingAssembly();
var attr = Attribute.GetCustomAttribute(assembly, typeof(BuildDateTimeAttribute)) as BuildDateTimeAttribute;
if (DateTime.TryParse(attr?.Date, out DateTime dt))
return dt;
else
return null;
}
Note 1 (per Flydog57 in the comments): If your .csproj has property GenerateAssemblyInfo listed in it and set to false, the build won't generate assembly info and you'll get no BuildDateTime info in your assembly. So either do not mention GenerateAssemblyInfo in your .csproj (this is the default behaviour for a new project, and GenerateAssemblyInfo defaults to true if not specifically set to false), or explicitly set it to true.
Note 2 (per Teddy in the comments): In the _Parameter1 example given, we're using ::Now to make use of DateTime.Now, which is the local date and time on your computer, subject to Daylight Savings Time when applicable and your local timezone. You could if you want use ::UtcNow to make use of DateTime.UtcNow so that the build date and time is recorded as UTC/GMT.
For anyone that needs to get the compile time in Windows 8 / Windows Phone 8:
public static async Task<DateTimeOffset?> RetrieveLinkerTimestamp(Assembly assembly)
{
var pkg = Windows.ApplicationModel.Package.Current;
if (null == pkg)
{
return null;
}
var assemblyFile = await pkg.InstalledLocation.GetFileAsync(assembly.ManifestModule.Name);
if (null == assemblyFile)
{
return null;
}
using (var stream = await assemblyFile.OpenSequentialReadAsync())
{
using (var reader = new DataReader(stream))
{
const int PeHeaderOffset = 60;
const int LinkerTimestampOffset = 8;
//read first 2048 bytes from the assembly file.
byte[] b = new byte[2048];
await reader.LoadAsync((uint)b.Length);
reader.ReadBytes(b);
reader.DetachStream();
//get the pe header offset
int i = System.BitConverter.ToInt32(b, PeHeaderOffset);
//read the linker timestamp from the PE header
int secondsSince1970 = System.BitConverter.ToInt32(b, i + LinkerTimestampOffset);
var dt = new DateTimeOffset(1970, 1, 1, 0, 0, 0, DateTimeOffset.Now.Offset) + DateTimeOffset.Now.Offset;
return dt.AddSeconds(secondsSince1970);
}
}
}
For anyone that needs to get the compile time in Windows Phone 7:
public static async Task<DateTimeOffset?> RetrieveLinkerTimestampAsync(Assembly assembly)
{
const int PeHeaderOffset = 60;
const int LinkerTimestampOffset = 8;
byte[] b = new byte[2048];
try
{
var rs = Application.GetResourceStream(new Uri(assembly.ManifestModule.Name, UriKind.Relative));
using (var s = rs.Stream)
{
var asyncResult = s.BeginRead(b, 0, b.Length, null, null);
int bytesRead = await Task.Factory.FromAsync<int>(asyncResult, s.EndRead);
}
}
catch (System.IO.IOException)
{
return null;
}
int i = System.BitConverter.ToInt32(b, PeHeaderOffset);
int secondsSince1970 = System.BitConverter.ToInt32(b, i + LinkerTimestampOffset);
var dt = new DateTimeOffset(1970, 1, 1, 0, 0, 0, DateTimeOffset.Now.Offset) + DateTimeOffset.Now.Offset;
dt = dt.AddSeconds(secondsSince1970);
return dt;
}
NOTE: In all cases you're running in a sandbox, so you'll only be able to get the compile time of assemblies that you deploy with your app. (i.e. this won't work on anything in the GAC).
The option not discussed here is to insert your own data into AssemblyInfo.cs, the "AssemblyInformationalVersion" field seems appropriate - we have a couple of projects where we were doing something similar as a build step (however I'm not entirely happy with the way that works so don't really want to reproduce what we've got).
There's an article on the subject on codeproject: http://www.codeproject.com/KB/dotnet/Customizing_csproj_files.aspx
I needed a universal solution that worked with a NETStandard project on any platform (iOS, Android, and Windows.) To accomplish this, I decided to automatically generate a CS file via a PowerShell script. Here is the PowerShell script:
param($outputFile="BuildDate.cs")
$buildDate = Get-Date -date (Get-Date).ToUniversalTime() -Format o
$class =
"using System;
using System.Globalization;
namespace MyNamespace
{
public static class BuildDate
{
public const string BuildDateString = `"$buildDate`";
public static readonly DateTime BuildDateUtc = DateTime.Parse(BuildDateString, null, DateTimeStyles.AssumeUniversal | DateTimeStyles.AdjustToUniversal);
}
}"
Set-Content -Path $outputFile -Value $class
Save the PowerScript file as GenBuildDate.ps1 and add it your project. Finally, add the following line to your Pre-Build event:
powershell -File $(ProjectDir)GenBuildDate.ps1 -outputFile $(ProjectDir)BuildDate.cs
Make sure BuildDate.cs is included in your project. Works like a champ on any OS!
A different, PCL-friendly approach would be to use an MSBuild inline task to substitute the build time into a string that is returned by a property on the app. We are using this approach successfully in an app that has Xamarin.Forms, Xamarin.Android, and Xamarin.iOS projects.
EDIT:
Simplified by moving all of the logic into the SetBuildDate.targets file, and using Regex instead of simple string replace so that the file can be modified by each build without a "reset".
The MSBuild inline task definition (saved in a SetBuildDate.targets file local to the Xamarin.Forms project for this example):
<Project xmlns='http://schemas.microsoft.com/developer/msbuild/2003' ToolsVersion="12.0">
<UsingTask TaskName="SetBuildDate" TaskFactory="CodeTaskFactory"
AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.v12.0.dll">
<ParameterGroup>
<FilePath ParameterType="System.String" Required="true" />
</ParameterGroup>
<Task>
<Code Type="Fragment" Language="cs"><![CDATA[
DateTime now = DateTime.UtcNow;
string buildDate = now.ToString("F");
string replacement = string.Format("BuildDate => \"{0}\"", buildDate);
string pattern = #"BuildDate => ""([^""]*)""";
string content = File.ReadAllText(FilePath);
System.Text.RegularExpressions.Regex rgx = new System.Text.RegularExpressions.Regex(pattern);
content = rgx.Replace(content, replacement);
File.WriteAllText(FilePath, content);
File.SetLastWriteTimeUtc(FilePath, now);
]]></Code>
</Task>
</UsingTask>
</Project>
Invoking the above inline task in the Xamarin.Forms csproj file in target BeforeBuild:
<!-- To modify your build process, add your task inside one of the targets below and uncomment it.
Other similar extension points exist, see Microsoft.Common.targets. -->
<Import Project="SetBuildDate.targets" />
<Target Name="BeforeBuild">
<SetBuildDate FilePath="$(MSBuildProjectDirectory)\BuildMetadata.cs" />
</Target>
The FilePath property is set to a BuildMetadata.cs file in the Xamarin.Forms project that contains a simple class with a string property BuildDate, into which the build time will be substituted:
public class BuildMetadata
{
public static string BuildDate => "This can be any arbitrary string";
}
Add this file BuildMetadata.cs to project. It will be modified by every build, but in a manner that allows repeated builds (repeated replacements), so you may include or omit it in source control as desired.
You can use this project: https://github.com/dwcullop/BuildInfo
It leverages T4 to automate the build date timestamp. There are several versions (different branches) including one that gives you the Git Hash of the currently checked out branch, if you're into that sort of thing.
Disclosure: I wrote the module.
You could use a project post-build event to write a text file to your target directory with the current datetime. You could then read the value at run-time. It's a little hacky, but it should work.
I'm not sure, but maybe the Build Incrementer helps.
A small update on the "New Way" answer from Jhon.
You need to build the path instead of using the CodeBase string when working with ASP.NET/MVC
var codeBase = assembly.GetName().CodeBase;
UriBuilder uri = new UriBuilder(codeBase);
string path = Uri.UnescapeDataString(uri.Path);
You could launch an extra step in the build process that writes a date stamp to a file which can then be displayed.
On the projects properties tab look at the build events tab. There is an option to execute a pre or post build command.
I used Abdurrahim's suggestion. However, it seemed to give a weird time format and also added the abbreviation for the day as part of the build date; example: Sun 12/24/2017 13:21:05.43. I only needed just the date so I had to eliminate the rest using substring.
After adding the echo %date% %time% > "$(ProjectDir)\Resources\BuildDate.txt"to the pre-build event, I just did the following:
string strBuildDate = YourNamespace.Properties.Resources.BuildDate;
string strTrimBuildDate = strBuildDate.Substring(4).Remove(10);
The good news here is that it worked.
A full solution step by step for Visual Studio 2019, like the one I wish I had found when I began years ago.
Add a text resource file
Access the properties of your project: from the solution explorer, select your project, then right-click -> properties, or Alt+Enter. In the Resources tab, choose Files (Ctrl+5). Then Add Resource / Add New Text File. In the popup message, type the name of your resource, for example BuildDate: this will create a new text file BuildDate.txt in your Project/Resources folder, include it as Project file, and register it as a resource, which can then be accessed via Properties.Resources in C#, or My.Resources in VB.
Automatically update the resource file each time you build
Now you can tell Visual Studio to write a date into this file, each time it builds or rebuilds the project. For this, go to the Compile tab of the Project Properties, choose Build Events, and copy/paste the following into the "Pre-Build event command line" textbox:
powershell -Command "((Get-Date).ToUniversalTime()).ToString(\"s\") | Out-File '$(ProjectDir)Resources\BuildDate.txt'"
This line will locate BuildDate.txt and write today/NowUtc's date and time under the ISO8601 format, such as 2021-09-07T16:08:35
Obtain the build date at run-time by reading the file
You can then retrieve this date from your code at run-time, via the following helper (C#):
DateTime CurrentBuildDate = DateTime.Parse(Properties.Resources.BuildDate, null, System.Globalization.DateTimeStyles.RoundtripKind);
Credits
Base idea: https://stackoverflow.com/a/15502932/10794555
Improved through powershell by: https://stackoverflow.com/users/84898/dbruning
Stable parsing of ISO8601: How to create a .NET DateTime from ISO 8601 format
GetLastWriteTime isn't changed if you copy the assembly to another location.
public static class AssemblyExtensions
{
public static DateTime GetLinkerTime(this Assembly assembly)
{
return File.GetLastWriteTime(assembly.Location).ToLocalTime();
}
}
If this is a windows app, you can just use the application executable path:
new System.IO.FileInfo(Application.ExecutablePath).LastWriteTime.ToString("yyyy.MM.dd")
I just added pre-build event command:
powershell -Command Get-Date -Format 'yyyy-MM-ddTHH:mm:sszzz' > Resources\BuildDateTime.txt
in the project properties to generate a resource file that is then easy to read from the code.
I had difficulties with the suggested solutions with my project, a .Net Core 2.1 web application. I combined various suggestions from above and simplified, and also converted the date to my required format.
The echo command:
echo Build %DATE:~-4%/%DATE:~-10,2%/%DATE:~-7,2% %time% > "$(ProjectDir)\BuildDate.txt"
The code:
Logger.Info(File.ReadAllText(#"./BuildDate.txt").Trim());
It seems to work. The output:
2021-03-25 18:41:40,877 [1] INFO Config - Build 2021/03/25 18:41:37.58
Nothing very original, I just combined suggestions from here and other related questions, and simplified.
For .NET 5 I've used this method successfully. (Found here).
Add this to the .csproj file:
<SourceRevisionId>build$([System.DateTime]::UtcNow.ToString("yyyyMMddHHmmss"))</SourceRevisionId>
Method for getting build date:
private static DateTime GetBuildDate(Assembly assembly)
{
const string BuildVersionMetadataPrefix = "+build";
var attribute = assembly.GetCustomAttribute<AssemblyInformationalVersionAttribute>();
if (attribute?.InformationalVersion != null)
{
var value = attribute.InformationalVersion;
var index = value.IndexOf(BuildVersionMetadataPrefix);
if (index > 0)
{
value = value.Substring(index + BuildVersionMetadataPrefix.Length);
if (DateTime.TryParseExact(value, "yyyyMMddHHmmss", CultureInfo.InvariantCulture, DateTimeStyles.None, out var result))
{
return result;
}
}
}
return default;
}
Usage:
var buildTime = GetBuildDate(Assembly.GetExecutingAssembly());
buildTime = buildTime.ToLocalTime();
Use the following code.
File.GetCreationTime(Assembly.GetExecutingAssembly().Location)
It will return the date of creation of last dll. If debug is running, then it will display current date and time. I modified some code from one of the answers, because i couldn't comment on the answer. Comment for further discussions.
I would like the version property of my application to be incremented for each build but I'm not sure on how to enable this functionality in Visual Studio (2005/2008). I have tried to specify the AssemblyVersion as 1.0.* but it doesn't get me exactly what I want.
I'm also using a settings file and in earlier attempts when the assembly version changed my settings got reset to the default since the application looked for the settings file in another directory.
I would like to be able to display a version number in the form of 1.1.38 so when a user finds a problem I can log the version they are using as well as tell them to upgrade if they have an old release.
A short explanation of how the versioning works would also be appreciated. When does the build and revision number get incremented?
With the "Built in" stuff, you can't, as using 1.0.* or 1.0.0.* will replace the revision and build numbers with a coded date/timestamp, which is usually also a good way.
For more info, see the Assembly Linker Documentation in the /v tag.
As for automatically incrementing numbers, use the AssemblyInfo Task:
AssemblyInfo Task
This can be configured to automatically increment the build number.
There are 2 Gotchas:
Each of the 4 numbers in the Version string is limited to 65535. This is a Windows Limitation and unlikely to get fixed.
Why are build numbers limited to 65535?
Using with with Subversion requires a small change:
Using MSBuild to generate assembly version info at build time (including SubVersion fix)
Retrieving the Version number is then quite easy:
Version v = Assembly.GetExecutingAssembly().GetName().Version;
string About = string.Format(CultureInfo.InvariantCulture, #"YourApp Version {0}.{1}.{2} (r{3})", v.Major, v.Minor, v.Build, v.Revision);
And, to clarify: In .net or at least in C#, the build is actually the THIRD number, not the fourth one as some people (for example Delphi Developers who are used to Major.Minor.Release.Build) might expect.
In .net, it's Major.Minor.Build.Revision.
VS.NET defaults the Assembly version to 1.0.* and uses the following logic when auto-incrementing: it sets the build part to the number of days since January 1st, 2000, and sets the revision part to the number of seconds since midnight, local time, divided by two. See this MSDN article.
Assembly version is located in an assemblyinfo.vb or assemblyinfo.cs file. From the file:
' Version information for an assembly consists of the following four values:
'
' Major Version
' Minor Version
' Build Number
' Revision
'
' You can specify all the values or you can default the Build and Revision Numbers
' by using the '*' as shown below:
' <Assembly: AssemblyVersion("1.0.*")>
<Assembly: AssemblyVersion("1.0.0.0")>
<Assembly: AssemblyFileVersion("1.0.0.0")>
I have found that it works well to simply display the date of the last build using the following wherever a product version is needed:
System.IO.File.GetLastWriteTime(System.Reflection.Assembly.GetExecutingAssembly().Location).ToString("yyyy.MM.dd.HH.mm.ss")
Rather than attempting to get the version from something like the following:
System.Reflection.Assembly assembly = System.Reflection.Assembly.GetExecutingAssembly();
object[] attributes = assembly.GetCustomAttributes(typeof(System.Reflection.AssemblyFileVersionAttribute), false);
object attribute = null;
if (attributes.Length > 0)
{
attribute = attributes[0] as System.Reflection.AssemblyFileVersionAttribute;
}
[Visual Studio 2017, .csproj properties]
To automatically update your PackageVersion/Version/AssemblyVersion property (or any other property), first, create a new Microsoft.Build.Utilities.Task class that will get your current build number and send back the updated number (I recommend to create a separate project just for that class).
I manually update the major.minor numbers, but let MSBuild to automatically update the build number (1.1.1, 1.1.2, 1.1.3, etc. :)
using Microsoft.Build.Framework;
using System;
using System.Collections.Generic;
using System.Text;
public class RefreshVersion : Microsoft.Build.Utilities.Task
{
[Output]
public string NewVersionString { get; set; }
public string CurrentVersionString { get; set; }
public override bool Execute()
{
Version currentVersion = new Version(CurrentVersionString ?? "1.0.0");
DateTime d = DateTime.Now;
NewVersionString = new Version(currentVersion.Major,
currentVersion.Minor, currentVersion.Build+1).ToString();
return true;
}
}
Then call your recently created Task on MSBuild process adding the next code on your .csproj file:
<Project Sdk="Microsoft.NET.Sdk">
...
<UsingTask TaskName="RefreshVersion" AssemblyFile="$(MSBuildThisFileFullPath)\..\..\<dll path>\BuildTasks.dll" />
<Target Name="RefreshVersionBuildTask" BeforeTargets="Pack" Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
<RefreshVersion CurrentVersionString="$(PackageVersion)">
<Output TaskParameter="NewVersionString" PropertyName="NewVersionString" />
</RefreshVersion>
<Message Text="Updating package version number to $(NewVersionString)..." Importance="high" />
<XmlPoke XmlInputPath="$(MSBuildProjectDirectory)\mustache.website.sdk.dotNET.csproj" Query="/Project/PropertyGroup/PackageVersion" Value="$(NewVersionString)" />
</Target>
...
<PropertyGroup>
..
<PackageVersion>1.1.4</PackageVersion>
..
When picking Visual Studio Pack project option (just change to BeforeTargets="Build" for executing the task before Build) the RefreshVersion code will be triggered to calculate the new version number, and XmlPoke task will update your .csproj property accordingly (yes, it will modify the file).
When working with NuGet libraries, I also send the package to NuGet repository by just adding the next build task to the previous example.
<Message Text="Uploading package to NuGet..." Importance="high" />
<Exec WorkingDirectory="$(MSBuildProjectDirectory)\bin\release" Command="c:\nuget\nuget push *.nupkg -Source https://www.nuget.org/api/v2/package" IgnoreExitCode="true" />
c:\nuget\nuget is where I have the NuGet client (remember to save your NuGet API key by calling nuget SetApiKey <my-api-key> or to include the key on the NuGet push call).
Just in case it helps someone ^_^.
What source control system are you using?
Almost all of them have some form of $ Id $ tag that gets expanded when the file is checked in.
I usually use some form of hackery to display this as the version number.
The other alternative is use to use the date as the build number: 080803-1448
Some time ago I wrote a quick and dirty exe that would update the version #'s in an assemblyinfo.{cs/vb} - I also have used rxfind.exe (a simple and powerful regex-based search replace tool) to do the update from a command line as part of the build process. A couple of other helpfule hints:
separate the assemblyinfo into product parts (company name, version, etc.) and assembly specific parts (assembly name etc.). See here
Also - i use subversion, so I found it helpful to set the build number to subversion revision number thereby making it really easy to always get back to the codebase that generated the assembly (e.g. 1.4.100.1502 was built from revision 1502).
If you want an auto incrementing number that updates each time a compilation is done, you can use VersionUpdater from a pre-build event. Your pre-build event can check the build configuration if you prefer so that the version number will only increment for a Release build (for example).
Here is a handcranked alternative option: This is a quick-and-dirty PowerShell snippet I wrote that gets called from a pre-build step on our Jenkins build system.
It sets the last digit of the AssemblyVersion and AssemblyFileVersion to the value of the BUILD_NUMBER environment variable which is automatically set by the build system.
if (Test-Path env:BUILD_NUMBER) {
Write-Host "Updating AssemblyVersion to $env:BUILD_NUMBER"
# Get the AssemblyInfo.cs
$assemblyInfo = Get-Content -Path .\MyShinyApplication\Properties\AssemblyInfo.cs
# Replace last digit of AssemblyVersion
$assemblyInfo = $assemblyInfo -replace
"^\[assembly: AssemblyVersion\(`"([0-9]+)\.([0-9]+)\.([0-9]+)\.[0-9]+`"\)]",
('[assembly: AssemblyVersion("$1.$2.$3.' + $env:BUILD_NUMBER + '")]')
Write-Host ($assemblyInfo -match '^\[assembly: AssemblyVersion')
# Replace last digit of AssemblyFileVersion
$assemblyInfo = $assemblyInfo -replace
"^\[assembly: AssemblyFileVersion\(`"([0-9]+)\.([0-9]+)\.([0-9]+)\.[0-9]+`"\)]",
('[assembly: AssemblyFileVersion("$1.$2.$3.' + $env:BUILD_NUMBER + '")]')
Write-Host ($assemblyInfo -match '^\[assembly: AssemblyFileVersion')
$assemblyInfo | Set-Content -Path .\MyShinyApplication\Properties\AssemblyInfo.cs -Encoding UTF8
} else {
Write-Warning "BUILD_NUMBER is not set."
}