From: Wayne Vucenic <wvucenic@...>
Date: 2003-09-28T14:08:42+09:00
Subject: RubyDotNet and Drag and Drop

I just heard about RubyDotNet, and it looks really great!

I did encounter a problem while trying to use drag and drop.  (RubyDotNet
r4, Ruby 1.8, .NET 1.1, Windows XP).  Here's a stripped down piece of
code that demonstrates the problem:

     require 'dotnet'

     loadLibrary 'System.Windows.Forms'

     form = Form.new
     form.topMost = true
     form.text = 'Drag and Drop Test'
     form.AllowDrop = true;

     Application.Run form

When I run this I get a "Microsoft .NET Framework" dialog saying "An
unhandled exception has occurred in your application...DragDrop
registration failed" with the following details:

************** Exception Text **************
System.InvalidOperationException: DragDrop registration failed. --->
System.Threading.ThreadStateException: The current thread must set to
Single Thread Apartment (STA) mode before OLE calls can be made.
Ensure that your Main function has STAThreadAttribute marked on it.
at System.Windows.Forms.Control.SetAcceptDrops(Boolean accept)
--- End of inner exception stack trace ---
at System.Windows.Forms.Control.SetAcceptDrops(Boolean accept)
at System.Windows.Forms.Control.OnHandleCreated(EventArgs e)
at System.Windows.Forms.Form.OnHandleCreated(EventArgs e)
at System.Windows.Forms.Control.WmCreate(Message& m)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
at System.Windows.Forms.ContainerControl.WndProc(Message& m)
at System.Windows.Forms.Form.WmCreate(Message& m)
at System.Windows.Forms.Form.WndProc(Message& m)
at System.Windows.Forms.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg,
IntPtr wparam, IntPtr lparam)

Thanks!!!

Wayne
No Bugs Software
"Ruby and C++ Contract Programming in Silicon Valley"