[mono-vb] System.NullReferenceException: Object reference not set to an instance of an object at System.Windows.Forms.TreeView.MouseMoveHandler when dragging a node in a treeview

[Rolf Bjarne Kvinge]

Hi,

Try executing mono like this:

MONO_INLINE_LIMIT=0 mono --debug yourapp.exe

This will get a better stack trace (the line numbers are off, most likely
due to inlining).

Rolf

> -----Original Message-----
> From: mono-vb-bounces at lists.ximian.com [mailto:mono-vb-
> bounces at lists.ximian.com] On Behalf Of Easy_Rider9999
> Sent: domingo, 17 de mayo de 2009 13:53
> To: mono-vb at lists.ximian.com
> Subject: [mono-vb] System.NullReferenceException: Object reference not
> set to an instance of an object at
> System.Windows.Forms.TreeView.MouseMoveHandler when dragging a node in
> a treeview
> 
> 
> I am always getting this error, when dragging a node in my treeview. I
> reported this error to Novell, but they say, that they can't reproduce
> it. I
> get this Error with Mono 2.4 (both windows and Ubuntu 8.04). Is anybody
> there that can reproduce this error? You can get my application at
> https://sourceforge.net/project/showfiles.php?group_id=257087&package_i
> d=315752&release_id=675230
> 
> This is the Error message:
> 
> System.NullReferenceException: Object reference not set to an instance
> of an
> obj
> ect
>   at System.Windows.Forms.TreeView.MouseMoveHandler (System.Object
> sender,
> Syste
> m.Windows.Forms.MouseEventArgs e) [0x0015a] in
> C:\cygwin\tmp\monobuild\build\BUI
> LD\mono-
> 2.4\mcs\class\Managed.Windows.Forms\System.Windows.Forms\TreeView.cs:22
> 3
> 0
>   at (wrapper delegate-invoke)
> System.Windows.Forms.MouseEventHandler:invoke_voi
> d__this___object_MouseEventArgs
> (object,System.Windows.Forms.MouseEventArgs)
>   at System.Windows.Forms.Control.OnMouseMove
> (System.Windows.Forms.MouseEventAr
> gs e) [0x0001c] in
> C:\cygwin\tmp\monobuild\build\BUILD\mono-2.4\mcs\class\Manage
> d.Windows.Forms\System.Windows.Forms\Control.cs:6382
>   at System.Windows.Forms.Control.WmMouseMove
> (System.Windows.Forms.Message&
> m)
> [0x00064] in
> C:\cygwin\tmp\monobuild\build\BUILD\mono-2.4\mcs\class\Managed.Wind
> ows.Forms\System.Windows.Forms\Control.cs:5783
>   at System.Windows.Forms.Control.WndProc
> (System.Windows.Forms.Message& m)
> [0x0
> 01d4] in
> C:\cygwin\tmp\monobuild\build\BUILD\mono-2.4\mcs\class\Managed.Windows.
> Forms\System.Windows.Forms\Control.cs:5387
>   at System.Windows.Forms.TreeView.WndProc
> (System.Windows.Forms.Message& m)
> [0x
> 0006b] in
> C:\cygwin\tmp\monobuild\build\BUILD\mono-2.4\mcs\class\Managed.Windows
> .Forms\System.Windows.Forms\TreeView.cs:1198
>   at System.Windows.Forms.Control+ControlWindowTarget.OnMessage
> (System.Windows.
> Forms.Message& m) [0x00000] in
> C:\cygwin\tmp\monobuild\build\BUILD\mono-2.4\mcs\
> class\Managed.Windows.Forms\System.Windows.Forms\Control.cs:234
>   at System.Windows.Forms.Control+ControlNativeWindow.WndProc
> (System.Windows.Fo
> rms.Message& m) [0x00000] in
> C:\cygwin\tmp\monobuild\build\BUILD\mono-2.4\mcs\cl
> ass\Managed.Windows.Forms\System.Windows.Forms\Control.cs:215
>   at System.Windows.Forms.NativeWindow.WndProc (IntPtr hWnd, Msg msg,
> IntPtr
> wPa
> ram, IntPtr lParam) [0x00085] in
> C:\cygwin\tmp\monobuild\build\BUILD\mono-2.4\mc
> s\class\Managed.Windows.Forms\System.Windows.Forms\NativeWindow.cs:242
> frmMain.tvMed_BeforeSelect Start
> frmMain.Form_Activate Start
> 
> Regards
> 
> Hans
> --
> View this message in context:
> http://www.nabble.com/System.NullReferenceException%3A-Object-
> reference-not-set-to-an-instance-of-an-object---at-
> System.Windows.Forms.TreeView.MouseMoveHandler-when-dragging-a-node-in-
> a-treeview-tp23582605p23582605.html
> Sent from the Mono - VB mailing list archive at Nabble.com.
> 
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