While working on a decent sized Windows Forms app in c#, I've seen a sporadic issue crop up that is incredibly difficult to debug. The form simply has a listview on it that is populated from a worker thread. The calls are all done with Invoke, on the UI thread. But, every once and awhile (it's sporadic). .NET throws this:
Unhandled Exception: System.NullReferenceException: Object reference not set to an instance of an object.
at System.Windows.Forms.ListViewItemCollection.get_Item(Int32 displayIndex)
at System.Windows.Forms.ListView.OnHandleDestroyed(EventArgs e)
at System.Windows.Forms.Control.WmDestroy(Message& m)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ListView.WndProc(Message& m)
at System.Windows.Forms.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
at System.Windows.Forms.ComponentManager.System.Windows.Forms.UnsafeNativeMethods+IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)
at System.Windows.Forms.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
at System.Windows.Forms.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
at System.Windows.Forms.Application.RunDialog(Form form)
at System.Windows.Forms.Form.ShowDialog(IWin32Window owner)
at System.Windows.Forms.Form.ShowDialog()
I can't find out where this is coming from, it has no reference to anything in the app, it's all in the framework.
Anyone seen this?