System.OverflowException in CallWindowProc for 64 bit configuration when called from C# code.

Hi,

We have the following piece of C# code in our application:

private IntPtr _DefaultWndProc = IntPtr.Zero;

[DllImport("user32")]

private static extern IntPtr SetWindowLongPtr(IntPtr hwnd, int index, WndProcPointer wndProcPointer);

[DllImport("user32")]

private static extern IntPtr SetWindowLongPtr(IntPtr hwnd, int index, IntPtr wndProc);

[DllImport("user32")]

private static extern IntPtr GetWindowLongPtr(IntPtr hwnd, int index);

[DllImport("User32.dll", CharSet = CharSet.Auto)]

private static extern int CallWindowProc(IntPtr wndProc, IntPtr hwnd, int msg, IntPtr wparam, IntPtr lparam);

private const int GWL_WNDPROC = (-4);

private const int WM_NCDESTROY = 0x0082;

private delegate int WndProcPointer(IntPtr hwnd, int msg, IntPtr wparam, IntPtr lparam);

protected virtual int WndProc(IntPtr hwnd, int msg, IntPtr wparam, IntPtr lparam)

{

return CallWindowProc(_DefaultWndProc, hwnd, msg, wparam, lparam);

}

_DefaultWndProc is being set as follows:

_DefaultWndProc = SetWindowLongPtr(control.Handle, GWL_WNDPROC, _MyWndProc);

When we compile and execute this program for 32 bit configuration everything works fine.

However, if we set the configuration for 64 bit, the method call "CallWindowProc(_DefaultWndProc, hwnd, msg, wparam, lparam)" listed above is throwing the following exception:

System.OverflowException - {"Arithmetic operation resulted in an overflow."}

This occurs only when we move the mouse cursor over certain columns in a ListView.

Thanks!