Develop Reference

Unable to get a string out of a method

I am really new to coding, never studied it or something similar, just learning it myself, never done it before, but I am trying to create my first real application right new.
However, I have some problems for 2 days which I just can't figure out, so I hope you can help me out.
Alright, so before the youtubedlCurrentWorker_Process() is created, I did define 'public string CurrentYouTubeDLVersion'.
How ever, when a button in my application executes the youtubedlCompareVersion_Process(), the CurrentYouTubeDLVersion string is empty, when it comes at the compare point.
Below is just a little part of my code.
Why is the string CurrentYouTubeDLVersion empty in the CompareVersion while the GetCurrentVersion ran before it?
Even if I double click "CurrentYouTubeDLVersion" in Visual Studio, it won't show a link to the one in the GetCurrentVersion_Process.
namespace MediaDownloader
{
public partial class updates : UserControl
{
public string LatestYoutubeDLVersion;
public string CurrentYouTubeDLVersion;
public void youtubedlGetCurrentVersion_Process()
{
if (File.Exists(YouTubeDLPath))
{
//Here I get the current version of youtube-dl.exe, to get the version number, we have to run youtube-dl.exe --version
Process youtubedl = new Process();
youtubedl.StartInfo.CreateNoWindow = true;
youtubedl.StartInfo.UseShellExecute = false;
youtubedl.StartInfo.RedirectStandardOutput = true;
youtubedl.StartInfo.RedirectStandardError = true;
youtubedl.StartInfo.FileName = YouTubeDLPath;
youtubedl.StartInfo.Arguments = " --version";
youtubedl.Start();
string CurrentYouTubeDLVersion = youtubedl.StandardOutput.ReadToEnd();
this.Dispatcher.Invoke((Action)(() =>
{
CurrentYouTubeDLVersionText.Text = "Current youtube-dl.exe version: " + CurrentYouTubeDLVersion;
YouTubeDLVersionStatusText.Text = null;
UpdateYouTubeDL.IsEnabled = false;
}));
}
public void youtubedlCompareVersion_Process()
{
youtubedlGetCurrentVersion_Process();
string LatestYoutubeDLVersion = WebClient.DownloadString("https://yt-dl.org/latest/version");
MessageBox.Show("Latest:" + LatestYoutubeDLVersion + "Current " + CurrentYouTubeDLVersion);
int YouTubeDLUptodate = CurrentYouTubeDLVersion.CompareTo(LatestYoutubeDLVersion);
if (YouTubeDLUptodate < 1)
{
YouTubeDLVersionStatusText.Text = "Your youtube-dl.exe is out of date, please click the button below to update.";
UpdateYouTubeDL.IsEnabled = true;
}
else
{
YouTubeDLVersionStatusText.Text = "youtube-dl.exe is up to date!";
UpdateYouTubeDL.IsEnabled = false;
}
}
}

Inside the youtubedlGetCurrentVersion_Process method, you're creating a new CurrentYouTubeDLVersion string, and it's completely separate from the public CurrentYouTubeDLVersion you added to the top of the class.
string CurrentYouTubeDLVersion = youtubedl.StandardOutput.ReadToEnd();
Assign to the class-level variable you made, instead of creating a new string:
CurrentYouTubeDLVersion = youtubedl.StandardOutput.ReadToEnd();
Then the value will be available to you in youtubedlCompareVersion_Process.

Take out the 'string' in front of CurrentYouTubeDLVersion and it should work
public youtubedlGetCurrentVersion_Process()
{
/* removed code to make easier to read */
//string CurrentYouTubeDLVersion = youtubedl.StandardOutput.ReadToEnd();
CurrentYouTubeDLVersion = youtubedl.StandardOutput.ReadToEnd();
/* removed code to make easier to read */
}

How to get the value of a property of a class in a non executing assembly through reflection

I'm having trouble while getting the value of the text property in a non-executing assembly; I read an assembly from disk via reflection, then i get all classes in the assembly to search for the Text property in a windows form class which is initialized by win forms designer. So far i have the following code:
static void Main(string[] args)
{
Assembly asm = Assembly.LoadFrom(Path.Combine(path, "Assembly.exe"));
PropertyInfo[] props;
foreach (Type t in asm.GetTypes())
{
var value = t.GetProperty("Text").GetValue(/*Not sure what to put here*/)
}
}
And this is how the designer generated the form
Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.None
Me.BackColor = System.Drawing.Color.FromArgb(CType(CType(0, Byte), Integer), CType(CType(128, Byte), Integer), CType(CType(128, Byte), Integer))
Me.ClientSize = New System.Drawing.Size(234, 181)
Me.Cursor = System.Windows.Forms.Cursors.Default
Me.Font = New System.Drawing.Font("Arial", 8.25!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
Me.ForeColor = System.Drawing.SystemColors.WindowText
Me.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedDialog
Me.Location = New System.Drawing.Point(581, 222)
Me.MaximizeBox = False
Me.MinimizeBox = False
Me.Name = "winform"
Me.RightToLeft = System.Windows.Forms.RightToLeft.No
Me.StartPosition = System.Windows.Forms.FormStartPosition.Manual
Me.Text = "Title"
Me.fraDías.ResumeLayout(False)
Me.ResumeLayout(False)
Keep in mind that the assembly is on disk and non-executing and that I want to retrieve the value of the Text property of every winform (I guess it should be somewhere hardcoded in the assembly since it was generated by the winforms designer)
Please tell me if this is possible, thanks!

Your requirements are contradictory, when you load an aseembly via reflection, and instantiate an object or try to get a property value, what happens is that some code begins to run, there is no way around that.
Remember that properties are just "syntax sugar" for a pair of methods, the getter and setter. Their current value is nothing but the value returned by the getter method, and when you change its value, you're in fact calling its setter method. So, to retrieve property values, you must make some code to run, even if it's a trivial get method.
I think maybe your confusion comes from the fact that you're using a designer to create the form. Particularly with the WinForms designer (WPF for instance is substantially different), all it does is to autogenerate some code for you. Setting properties, placing and moving controls around, what's happening under the hood is that it writes code that replicate your actions at runtime, specifically, it codes the InitializeComponent method. The real property value is set when the constructor is called (that in turn calls InitializeComponent), and then you may read/change using many properties.
What you would need to read those designer attributes is that those were hardcoded in some form of metadata, so that it's simply read as data and not as the result of code execution. That's not the case with WinForms, as it "saves" the form as code.

You cannot read a property of a class that has not been instantiated! The parameter you are missing is an instance of your type.
You must create an instance of the type with object o = Activator.CreateInstance(type); before accessing its members (unless they are static).
Your problem is related to how add-ins (plug-ins) can be loaded at runtime.
Here is how I made an Add-In Loader. Below, I will explain how you can adapt it to your problem. Add-Ins have to implement the IAddIn interface in my example. You are totally free in the definition of IAddIn. You could define it like this:
public interface IAddIn
{
bool OnLoad();
string Version { get; set; }
string Text { get; set; }
}
This allows you to access members without reflection.
public class AddInLoader
{
// Loads all non abstract types implementing IAddIn in all DLLs found in a folder.
public IList<IAddIn> Load(string folder)
{
var addIns = new List<IAddIn>();
string[] files = Directory.GetFiles(folder, "*.dll");
foreach (string file in files) {
addIns.AddRange(LoadFromAssembly(file));
}
return addIns;
}
// Loads all non abstract types implementing IAddIn found in a file.
private static IEnumerable<IAddIn> LoadFromAssembly(string fileName)
{
Assembly asm = Assembly.LoadFrom(fileName);
string addInInterfaceName = typeof(IAddIn).FullName;
foreach (Type type in asm.GetExportedTypes()) {
Type interfaceType = type.GetInterface(addInInterfaceName);
if (interfaceType != null &&
(type.Attributes & TypeAttributes.Abstract) != TypeAttributes.Abstract){
IAddIn addIn = (IAddIn)Activator.CreateInstance(type);
addIn.Version = asm.GetName().Version.ToString();
yield return addIn;
}
}
}
}
Now you can load and access the add-ins like this:
var loader = new AddInLoader();
IList<IAddIn> addIns = loader.Load(folderPath);
foreach (IAddIn addIn in addIns) {
if (addIn.OnLoad()) {
Console.WriteLine("Version = {0}, Text = {1}", addIn.Version, addIn.Text);
}
}
Reading the titles of Forms at runtime:
You can easily adapt this example. Instead of searching for types implementing an interface, search for types deriving from System.Windows.Forms.Form.
private static IEnumerable<Form> LoadFormsFromAssembly(string fileName)
{
Assembly asm = Assembly.LoadFrom(fileName);
foreach (Type type in asm.GetExportedTypes()) {
if (typeof(Form).IsAssignableFrom(type) &&
(type.Attributes & TypeAttributes.Abstract) != TypeAttributes.Abstract) {
Form form = (Form)Activator.CreateInstance(type);
yield return form;
}
}
}
Now you can get the texts of the forms like this:
var forms = LoadFormsFromAssembly(path);
foreach (Form frm in forms) {
Console.WriteLine(frm.Text);
}
Note: You must instantiate the forms, however you do not need to open (show) them. The code works only if the forms have a default constructor, i.e. a constructor without parameters.

You need an instance object for that type to get the value of a property.
It looks like you just want to check if a type has a "Text" property or not. You can to it by checking
bool hasTextProperty = t.GetProperty("Text") !=null;

Error in FAXCOMLib (c#)

I write a small program to send fax using FAXCOMLIB .
I make a class "fax" ,here is the code :
internal class Fax
{
public void SendFax( string FileName, string FaxNumber)
{
if (FaxNumber != "")
{
try
{
FAXCOMLib.FaxServer faxServer = new FAXCOMLib.FaxServerClass();
faxServer.Connect(Environment.MachineName);
FAXCOMLib.FaxDoc faxDoc = (FAXCOMLib.FaxDoc)faxServer.CreateDocument(FileName);
faxDoc.RecipientName = "گیرنده";
faxDoc.FaxNumber = FaxNumber;
faxDoc.DisplayName = "Asa";
int Response = faxDoc.Send();
faxServer.Disconnect();
}
catch (Exception Ex) { MessageBox.Show(Ex.Message); }
}
}
}
So when i want to execute the code i got these errors:
1-Error 13 Interop type 'FAXCOMLib.FaxServerClass' cannot be embedded. Use the applicable interface instead
2-Error 12 The type 'FAXCOMLib.FaxServerClass' has no constructors defined

in your project references, expand it and select the assembly in question (whatever the name is... FAX... whatever), then right click on it and go to properties. In there you will see the "Embed Interop Type" property - change it to "False"

Output Build Order of Visual Studio solution to a text file

Is there a way to output the Build order to a text file via command line?
To explain: We use multiple branches of source and have large solutions of 100+ projects on each branch. I need to write build scripts to build these solutions from command line. We can then tailor the solutions on the branches to only have project references for the projects that team are working on. This should greatly increase solution load time and ease the frustration of the Developers and me, I hope :)
I'm going to keep looking and maybe look at using C# and the APIs provided with VS. We are using 2012 update 1.

This is a good candidate for a Visual Studio Plugin project.
Create a new Visual Studio Add-in project.
In the project creation wizard make sure you choose the following configuration in the Choose Add-in Options step (the other steps are not important, I'm assuming you'll use C#):
In the Connect.cs file, add the following fields:
private BuildEvents _buildEvents;
private Events _events;
private bool buildEventConnected = false;
And add / modify these methods accordingly:
public void OnConnection(object application, ext_ConnectMode connectMode, object addInInst, ref Array custom)
{
_applicationObject = (DTE2)application;
_addInInstance = (AddIn)addInInst;
_events = _applicationObject.Events;
_buildEvents = _events.BuildEvents;
if (connectMode != ext_ConnectMode.ext_cm_UISetup && !buildEventConnected)
{
_buildEvents.OnBuildDone +=
new _dispBuildEvents_OnBuildDoneEventHandler(BuildEvents_OnBuildDone);
buildEventConnected = true;
}
}
private void BuildEvents_OnBuildDone(vsBuildScope Scope, vsBuildAction Action)
{
const string BUILD_OUTPUT_PANE_GUID = "{1BD8A850-02D1-11D1-BEE7-00A0C913D1F8}";
TextDocument txtOutput = default(TextDocument);
TextSelection txtSelection = default(TextSelection);
Window vsWindow = default(Window);
vsWindow = _applicationObject.Windows.Item(EnvDTE.Constants.vsWindowKindOutput);
OutputWindow vsOutputWindow = default(OutputWindow);
OutputWindowPane objBuildOutputWindowPane = default(OutputWindowPane);
vsOutputWindow = (OutputWindow)vsWindow.Object;
foreach (OutputWindowPane objOutputWindowPane in vsOutputWindow.OutputWindowPanes)
{
if (objOutputWindowPane.Guid.ToUpper() == BUILD_OUTPUT_PANE_GUID)
{
objBuildOutputWindowPane = objOutputWindowPane;
break;
}
}
txtOutput = objBuildOutputWindowPane.TextDocument;
txtSelection = txtOutput.Selection;
txtSelection.StartOfDocument(false);
txtSelection.EndOfDocument(true);
objBuildOutputWindowPane.OutputString(System.DateTime.Now.ToString());
txtSelection = txtOutput.Selection;
var solutionDir = System.IO.Path.GetDirectoryName(_applicationObject.Solution.FullName);
System.IO.File.WriteAllText(solutionDir + "\\build_output.log", txtSelection.Text);
}
public void OnDisconnection(ext_DisconnectMode disconnectMode, ref Array custom)
{
if (buildEventConnected)
{
_buildEvents.OnBuildDone -= new _dispBuildEvents_OnBuildDoneEventHandler(BuildEvents_OnBuildDone);
buildEventConnected = false;
}
}
That's it, on every build you'll have the output sent to the build_output.log file in your solution's folder.

Quick way is to do a "Clean Solution" so that you can see the inverted order in build log.

Custom workflow activity errors 'Value cannot be null'

I'm creating a custom workflow activity in VS2010 targeting .NET 3.5. The DLL is actually being used in a Microsoft System Center Service Manager custom workflow, but I don't think that is my issue.
I have a public string property, that the user types in the string of what the activity should use. However, when the WF runs, it errors out 'value cannot be null'. I want to target if it is my code or something else.
When we drag my custom activity onto the designer, I'm able to type in the text of the string on the designer for that property.
public static DependencyProperty ChangeRequestStageProperty = DependencyProperty.Register("ChangeRequestStage", typeof(String), typeof(UpdateChangeRequestStage));
[DescriptionAttribute("The value to set the ChangeRequestStage Property in the ChangeRequest Extension class.")]
[CategoryAttribute("Change Request Extension")]
[BrowsableAttribute(true)]
[DesignerSerializationVisibilityAttribute(DesignerSerializationVisibility.Visible)]
public String Stage
{
get { return ((String)(base.GetValue(UpdateChangeRequestStage.ChangeRequestStageProperty))); }
set { base.SetValue(UpdateChangeRequestStage.ChangeRequestStageProperty, value); }
}
protected override ActivityExecutionStatus Execute(ActivityExecutionContext executionContext)
{
EnterpriseManagementGroup emg = CreateEMG();
//System.WorkItem.ChangeRequest Extension - ClassExtension_928bec0a_cac4_4a0a_bd89_7146c9052fbe
ManagementPackClass mpcChangeRequest = emg.EntityTypes.GetClass(new Guid("8c6c6057-56ad-3862-47ec-dc0dde80a071"));
//System.WorkItemContainsActivity Relationship Class
ManagementPackRelationship workItemContainsActivityRelationship = emg.EntityTypes.GetRelationshipClass(new Guid("2DA498BE-0485-B2B2-D520-6EBD1698E61B"));
EnterpriseManagementObject changeRequest = null;
//Loop thru each emo (Change Request in this case), and assign it. There will never be more than 1 emo returned
foreach (EnterpriseManagementObject obj in emg.EntityObjects.GetRelatedObjects<EnterpriseManagementObject>(executionContext.ContextGuid, workItemContainsActivityRelationship, TraversalDepth.OneLevel, ObjectQueryOptions.Default))
{ changeRequest = obj; }
EnterpriseManagementObjectProjection emop = new EnterpriseManagementObjectProjection(changeRequest);
if (emop != null)
{ emop.Object[mpcChangeRequest, "ChangeRequestStage"].Value = Stage; }
emop.Commit();
return base.Execute(executionContext);
}
Since it is getting a 'value cannot be null' error, I'm guessing it's on this line:
emop.Object[mpcChangeRequest, "ChangeRequestStage"].Value = Stage;
I'm going to test and see if hardcoding a value works or not. Any ideas?
enter code here

try this
if (emop != null && emop.Object[mpcChangeRequest, "ChangeRequestStage"] != null)
emop.Object[mpcChangeRequest, "ChangeRequestStage"].Value = Stage

I didn't want to leave this question wide open, so I'm updating it as to how I resolved this (a long time ago).
Rather than working with an EnterpriseManagementObjectProjection (emop), I worked with a standard EnterpriseManagementObject (emo). From there, I was able to follow a similar format from above:
ManagementPackClass mpcChangeRequest = emg.EntityTypes.GetClass(new Guid("8c246fc5-4e5e-0605-dc23-91f7a362615b"));
changeRequest[mpcChangeRequest, "ChangeRequestStage"].Value = this.Stage;
changeRequest.Commit();