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I've tried to port a C#-Project to Mono. Compiling etc. went fine using XamarinStudio 5.9 but when I try to start the project using the mono runtime I got the following exception.
System.Runtime.InteropServices.GCHandle.op_Explicit (value=0x0) in C:\buildroot\release\repos\mono\mcs\class\corlib\System.Runtime.InteropServices\GCHandle.cs:123
System.Windows.Forms.XplatUIWin32.GetMessage (msg=, hWnd=, wFilterMin=, wFilterMax=, blocking=) in C:\buildroot\release\repos\mono\mcs\class\Managed.Windows.Forms\System.Windows.Forms\XplatUIWin32.cs:2080
System.Windows.Forms.XplatUIWin32.GetMessage (Parameters=) in C:\buildroot\release\repos\mono\mcs\class\Managed.Windows.Forms\System.Windows.Forms\XplatUIWin32.cs:2027
System.Windows.Forms.XplatUI.GetMessage (Parameters=) in C:\buildroot\release\repos\mono\mcs\class\Managed.Windows.Forms\System.Windows.Forms\XplatUI.cs:716
System.Windows.Forms.Application.RunLoop (Parameters=) in C:\buildroot\release\repos\mono\mcs\class\Managed.Windows.Forms\System.Windows.Forms\Application.cs:852
System.Windows.Forms.Application.Run (Parameters=) in C:\buildroot\release\repos\mono\mcs\class\Managed.Windows.Forms\System.Windows.Forms\Application.cs:724
System.Windows.Forms.Application.Run (Parameters=) in C:\buildroot\release\repos\mono\mcs\class\Managed.Windows.Forms\System.Windows.Forms\Application.cs:707
PlatoController.Program.Main (Parameters=) in D:\Entwicklung\Mono\Plato\PlatoController\App\Program.cs:79
An internet search only found similar questions but now answer.
Any hint what went wrong ?
System.Windows.Forms is no longer supported by mono.
Does that mean I should use winforms ? An if, how do I use it.
I'm using Xamarin Studio and the reference to System.Windows.Forms is checked. Do I have to exchange the standard lib through something else ?
You would need to use a new toolkit, something like Gtk# or Xwt.
This is likely a case of WM_ASYNC_MESSAGE being sent by the OS, and we just assume that we are the only senders of this message. The right fix is probably to ignore this message and pass it along to the OS, and use a different message code internal to Mono's Winforms to send async requests.