public void ShowDragVisual(Control control)
{
UpdatePosition();
User32.ShowWindow(this.Handle, 8);
User32.SetWindowPos(
this.Handle, (IntPtr)(-1),
0, 0, 0, 0,
0x0010 | 0x0002 | 0x001);
try
{
_hook = new LowLevelMouseHook();
_hook.Activate(0);
}
catch (Win32Exception)
{
if (_hook != null)
{
_hook.Dispose();
_hook = null;
}
}
if (_hook == null)
{
_timer.Enabled = true;
if (control != null)
{
control.GiveFeedback += OnControlGiveFeedback;
}
}
else
{
_hook.MouseMove += (s, e) =>
{
if (InvokeRequired)
{
BeginInvoke(new Action <Point>(UpdatePosition), e.Location);
}
else
{
UpdatePosition(e.Location);
}
};
_hook.MouseWheel += (s, e) =>
{
if (e.Delta == 0)
{
return;
}
var h = User32.WindowFromPoint(new POINT(e.X, e.Y));
if (h == IntPtr.Zero)
{
return;
}
User32.SendMessage(h, WM.MOUSEWHEEL, (IntPtr)(e.Delta << 16), (IntPtr)((e.Y << 16) | e.X));
};
}
}