protected override void OnSourceInitialized(EventArgs e)

{

　　base.OnSourceInitialized(e);

　　// Get this window's handle

　　IntPtr hWnd = new WindowInteropHelper(this).Handle;

　　// Get the extended window style

　　int exStyle = (int)GetWindowLong(hWnd, GWL_EXSTYLE);

　　// Set the WS_EX_TOOLWINDOW style

　　exStyle |= WS_EX_TOOLWINDOW;

　　SetWindowLong(hWnd, GWL_EXSTYLE, (IntPtr)exStyle);

}

// Win32 API declarations

private const int GWL_EXSTYLE = -20;

private const int WS_EX_TOOLWINDOW = 0x80;

[DllImport("user32.dll")]

private static extern IntPtr GetWindowLong(IntPtr hWnd, int nIndex);

[DllImport("user32.dll")]

private static extern IntPtr SetWindowLong(IntPtr hWnd, int nIndex, IntPtr dwNewLong);