I have developed a small windows service which performs few database operations. I have to give an option to the user to change server name on post-deploy. if user changes in app.config it doesn't affect the service, it is still reading connection strings from AppName.exe.config.
Here what I have tried.
<connectionStrings>
<add name="testString" connectionString="Data Source=ServerAddresss;Initial Catalog=DatabaseName;Integrated Security=True;" />
</connectionStrings>
C# code,
ConfigurationManager.ConnectionStrings["ProjectName.Properties.Settings.testString"].ConnectionString);
This returns a server connection string from AppName.exe.config file but I want to access it from App.config file.
can someone help me out in this?
App.config and AppName.exe.config aren't exactly separate - AppName.exe.config is the build output of app.config.
In other words, once the service is deployed, there shouldn't even be an app.config to change, and if there is, changing it won't do anything. AppName.exe.config is where your application gets "app.config" values.
If you need different configuration values for different environments, take a look at config transformations. They allow you to change or replace sections or individual values for different configurations such as debug, release, or other custom configurations.
This is useful because it means that all of the connection strings are part of the project and are in source control. You can do without this and just edit the config file in place on the server, but then there will be nothing in source control indicating where the connection string came from. And then if you redeploy the service the change will be overwritten unless someone remembers to make the same change every time. Having it in source control is much better.
For some reason that I do not understand, you can right-click a web.config and select "Add Config Transforms", but you can't do that with an app.config. Maybe there's a good reason.
You can install this extension which enables the same behavior for app.config. Then you can right-click on app.config and add a transformation for another configuration, like Release.
In that file (app.Release.config) add this:
<connectionStrings xdt:Transform="Replace">
<add name="testString" connectionString="...your Release connection string..." />
</connectionStrings>
When you build and deploy using the Release configuration it will replace the connectionStrings section with this one, leaving everything else just as it is. You can also right-click app.Release.config and select "Preview Config Transforms" to see the transformed file side-by-side with the original.
You should be able to just pull in an arbitrary file with a ConfigurationFileMap
System.Configuration.ConfigurationFileMap fileMap = new ConfigurationFileMap(strConfigPath); //Path to your config file
System.Configuration.Configuration configuration = System.Configuration.ConfigurationManager.OpenMappedMachineConfiguration(fileMap);
This question is a possible duplicate of: Using ConfigurationManager to load config from an arbitrary location
Also, you'll have to be sure that the service is restarted after updating the config file (either config file).
Related
I have an asp.net project that is using Entity Framework that is used on several different client servers. This means a different web.config for each for connectionstrings and app settings.
Hasn't been an issue but I changed something that altered the web.config file recently and I manually had to adjust this for each client, I also have to exclude the web.config file in updates to ensure their own one is not overwritten.
What I would like to achieve is store these settings in maybe another config file that the project can pick up and use. Maybe that on Globals Application_Start gets these and imports them/overwrites the current web.config file perhaps.
Essentially I don't want to affect the current code that uses the connection string and ConfigurationManager.AppSettings used throughout the project but I do want to be able to let the web.config file update for each client and use a seperate file for some settings.
NOTE: I do not have access to publish directly to each server so I can't simply write a different deploy web.config for each one. I have to publish the files locally, store as zip and automated routine on servers downloads and extracts accordingly.
EDIT:
Please do say if this is considered a bad idea but an idea I had was to put something similar in Global.asax Application_Start method:
Does config file exist?
If no, create file and append all current settings in web.config
If yes, open and import those settings to the current web.config overwriting the original values
Hopefully then in a few weeks time, after I have asked all clients to perform a manual update they will have this code and I can begin to include the web.config in updates.
In VS, inside the Build menu, the last item is Configuration Manager.
In here you can specify various different release environments which can each have their own web.config transforms.
This is normally used for production/staging/test environments. However, I can see no reason why you could not use this and have a configuration file for each of your servers/environments.
You will then need to create the transformations for each environment, by rightclicking the web.config, then selecting Add Config Transform.
each of the environments you had setup can then override the settings in the main web.config. (That now acts as a template/default settings)
e.g.
In Web.EnvironmentA.Config
<add key="ConnectionString" value="ConStringA" xdt:Transform="SetAttributes" xdt:Locator="Match(key)"/>
In Web.EnvironmentB.Config
<add key="ConnectionString" value="ConStringB" xdt:Transform="SetAttributes" xdt:Locator="Match(key)"/>
Then when you do a publish, you simply setup which config file to use. If you use Azure or the VS publish method, it will save each of these settings, so then you can simply push to the relevant environment easily.
Just make sure you test this works as you intent first, before you start publishing everywhere ;)
My problem is solved but I don't quite understand the solution and why it worked. I made a class library "Business Layer" inside a solution which also contains a Windows forms project (C#). Within the class library I put an app.config file and defined a connection string inside it, which I used in SQL-connection code in the business layer. Then I called the database logic in the Windows forms application, but the project failed at the connection string part (i.e., it returned null). However, when I copied app.config to the application project it started working. Why? Why is it that if I am using all database code in the business layer that pasting the code in the application project worked?
Code:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<configSections>
</configSections>
<connectionStrings>
<add name="ConnectionString" connectionString="Data Source=HOME-PC;Initial Catalog=LMS;Integrated Security=True"
providerName="System.Data.SqlClient" />
</connectionStrings>
</configuration>
getting:
string conStr = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString.ToString();
You are using the following code in your program:
string conStr = ConfigurationManager.ConnectionStrings["ConnectionString"]
.ConnectionString.ToString();
So, what does this do? Why is this important?
ConfigurationManager will look for the app.config or web.config (if you are making a web site) that corresponds to the running program. For example, if you have a program called "MyCoolProgram", you would have two output files called "MyCoolProgram.exe" and "MyCoolProgram.exe.config".
It's because of this naming structure that the ConfigurationManager is able to work.
But you already made an app.config, right? You made one in your referencing dll project. Why do you have to make another app.config with the same values?
So let's add in another project to our example. So far our example solution looks like this:
MyCoolProject (exe)
CommonLogic (dll)
If both projects have their own app.config file, the files listed in MyCoolProjects' bin folder would look like this:
MyCoolProject.exe
MyCoolProject.exe.config
CommonLogic.dll
So first, where is the config file for CommonLogic? It's not there. By default, a class library's config file is not copied over with the dll file, but you can see it still exists in CommonLogic's bin directory.
Second, so let's say that you do copy over CommonLogic's config file. You will have a file called CommonLogic.dll.config in MyCoolProject's bin directory. However, with "MyCoolProject.exe.config" empty, your code still can't find the connection string. It's strange because,
The connection string is set (only) in CommonLogic.dll.config
The code that is trying to get the connection string is from CommonLogic
So what gives?
Remember what I said before: ConfigurationManager will look for the app.config that corresponds to the running program, not the assembly that the code was ran from. No matter where your code is, the Configuration Manager is going to look at "MyCoolProject.exe.config" for any values. It's not going to look at anything else. For all intents and purposes, it doesn't even know about any other libraries or config files.
This means that you need to put your connection string (preferably exclusively) in the program that will be consuming the referencing library.
The class library should not be in charge of setting the connection string, that should be up to the program that uses it.
when I copied app.config in actual application project too then it started working, why ?
Because app.config is for the application, not the library. VS just gives you an app.config for a library to show you what should be put in the application configuration file.
It's perfectly reasonable to assume that a library can be used in multiple applications with different configurations, so tying the configuration to the library would make it harder to separate the configuration between applications.
Read a app.config value:
string configFile =
System.Configuration.ConfigurationManager.AppSettings["connStr"].ToString();
Config file:
<appSettings>
<add key="connStr" value="Data Source=Dolphin-PC;
Initial Catalog=jsptpd_SYS;
Persist Security Info=True;User ID=sa;
Password=ccir"/>
</appSettings>
Get an error:
Object reference not set to an instance of an object
the \program and debug\ folder contains app.config file.
Why woud this happen
Because, System.Configuration.ConfigurationManager.AppSettings["connStr"] is null
How could i deal it?
A more valid question. There isn't anything wrong with your code here. the main reason that you are finding it null is probably because your app.config is not present in the directory you are running the application from. It could be because app.config is part of some library and it is not copied to the output directory. You need to make sure that either app.config is in your main project or you copy it to the directory (you are running your applicatior from) explicitly.
To fixed the problem,you need to know the princeple of ConfigurationManager how to read the config file:
http://msdn.microsoft.com/en-us/library/system.configuration.configurationmanager.aspx
To solve this problem,you could make sure your bin/ directory generate yourprogram.exe.config file,so the ConfigurationManager could read.
If this file missing,you coud make sure your app.config attribute generate operation is not Embeded resource.If it is true,the app.config will embeded to the exe file and configurationmanager could not read.
I'm creating a web application, which calls a DLL to run unit tests, I also have another DLL(DataAccessLayer) which performs connections and performs queries to SQL which references the main DLL. Both the DLLs use the same config file to read settings.
When running application from VS, the application is working fine. However when the web app is deployed to IIS, it seems the DLLs are unable to read the settings from the config file.
After some research I found that I might have to explicitly define the configuration elements in the web.config file, however I don't know how to implement this. Can someone please point me in the right direction?
I'm actually retrieving the settings using the ConfigurationManager with the following code:-
public string GetValue(string key)
{
var appConfig = ConfigurationManager.OpenExeConfiguration("path to dll");
strKeyValue = appConfig.AppSettings.Settings[key].Value;
return strKeyValue;
}
Thanks.
Use WebConfigurationManager.AppSettings["HelloWorldKey"]; to read AppSettings from the web.config.
Just set all the appSettings values used by the DLL you mention, directly in the web.config PRIOR to deploying the app. You don't need to modify this at run-time (and you shouldn't anyway, since any modification to the web.config will cause the application to restart)
Add the connectionstring or AppSetting or ApplicationSettings used in you app.config into your web.config, I understand this is a manual task but is the only way that the config will read the settings.
Use following code to access connection string
string filePath= WebConfigurationManager.AppSettings["Pathfile"].ToString();
Web config Fie
<configuration>
....
<appSettings>
<add key="Pathfile" value="Path to dll"/>
</appSettings>
....
</configuration>
I have done a project in C#.NET where my database file is an Excel workbook. Since the location of the connection string is hard coded in my coding, there is no problem for installing it in my system, but for other systems there is.
Is there a way to prompt the user to set a path once after the setup of the application is completed?
The answers I got was "Use App.Config"... can anyone tell what is this App.config and how to use it in my context here?
At its simplest, the app.config is an XML file with many predefined configuration sections available and support for custom configuration sections. A "configuration section" is a snippet of XML with a schema meant to store some type of information.
Overview (MSDN)
Connection String Configuration (MSDN)
Settings can be configured using built-in configuration sections such as connectionStrings or appSettings. You can add your own custom configuration sections; this is an advanced topic, but very powerful for building strongly-typed configuration files.
Web applications typically have a web.config, while Windows GUI/service applications have an app.config file.
Application-level config files inherit settings from global configuration files like machine.config. Web also applications inherit settings from applicationHost.config.
Reading from the App.Config
Connection strings have a predefined schema that you can use. Note that this small snippet is actually a valid app.config (or web.config) file:
<?xml version="1.0"?>
<configuration>
<connectionStrings>
<add name="MyKey"
connectionString="Data Source=localhost;Initial Catalog=ABC;"
providerName="System.Data.SqlClient"/>
</connectionStrings>
</configuration>
Once you have defined your app.config, you can read it in code using the ConfigurationManager class. Don't be intimidated by the verbose MSDN examples; it's actually quite simple.
string connectionString = ConfigurationManager.ConnectionStrings["MyKey"].ConnectionString;
Writing to the App.Config
Frequently changing the *.config files is usually not a good idea, but it sounds like you only want to perform one-time setup.
See: Change connection string & reload app.config at run time which describes how to update the connectionStrings section of the *.config file at runtime.
Note that ideally you would perform such configuration changes from a simple installer.
Location of the App.Config at Runtime
Q: Suppose I manually change some <value> in app.config, save it and then close it. Now when I go to my bin folder and launch the .exe file from here, why doesn't it reflect the applied changes?
A: When you compile an application, its app.config is copied to the bin directory1 with a name that matches your exe. For example, if your exe was named "test.exe", there should be a ("text.exe.config" in .net framework) or ("text.dll.config" in .net core) in your bin directory. You can change the configuration without a recompile, but you will need to edit the config file that was created at compile time, not the original app.config.
1: Note that web.config files are not moved, but instead stay in the same location at compile and deployment time. One exception to this is when a web.config is transformed.
.NET Core
New configuration options were introduced with .NET Core and continue with the unified .NET (version 5+). The way that *.config files works hasn't fundamentally changed, but developers are free to choose new, more flexible configuration paradigms.
As with .NET Framework configuration .NET Core can get quite complex, but implementation can be as simple as a few lines of configuration with a few lines of c# to read it.
Configuration in ASP.NET Core
Configuration in .NET Core
Simply, App.config is an XML based file format that holds the Application Level Configurations.
Example:
<?xml version="1.0"?>
<configuration>
<appSettings>
<add key="key" value="test" />
</appSettings>
</configuration>
You can access the configurations by using ConfigurationManager as shown in the piece of code snippet below:
var value = System.Configuration.ConfigurationManager.AppSettings["key"];
// value is now "test"
Note: ConfigurationSettings is obsolete method to retrieve configuration information.
var value = System.Configuration.ConfigurationSettings.AppSettings["key"];
App.Config is an XML file that is used as a configuration file for your application. In other words, you store inside it any setting that you may want to change without having to change code (and recompiling). It is often used to store connection strings.
See this MSDN article on how to do that.
Just to add something I was missing from all the answers - even if it seems to be silly and obvious as soon as you know:
The file has to be named "App.config" or "app.config" and can be located in your project at the same level as e.g. Program.cs.
I do not know if other locations are possible, other names (like application.conf, as suggested in the ODP.net documentation) did not work for me.
PS. I started with Visual Studio Code and created a new project with "dotnet new". No configuration file is created in this case, I am sure there are other cases.
PPS. You may need to add a nuget package to be able to read the config file, in case of .NET CORE it would be "dotnet add package System.Configuration.ConfigurationManager --version 4.5.0"
You can access keys in the App.Config using:
ConfigurationSettings.AppSettings["KeyName"]
Take alook at this Thread
Just adding one more point
Using app.config some how you can control application access, you want apply particular change to entire application use app config file and you can access the settings like below
ConfigurationSettings.AppSettings["Key"]
Application settings enable you to store application information dynamically. Settings allow you to store information on the client computer that shouldn't be included in the application code (for example a connection string), user preferences, and other information you need at runtime.
To add an application configuration file to a C# project:
In Solution Explorer, right-click the project node, and then select Add > New Item.
The Add New Item dialog box appears.
Expand Installed > Visual C# Items.
In the middle pane, select the Application Configuration File template.
Select the Add button.
A file named App.config is added to your project.
take a look at this article