c#调用windows虚拟键盘

 private void (object sender, RoutedEventArgs e)
{
try
{
    dynamic file = "C:\Program Files\Common Files\microsoft  shared\ink\TabTip.exe";
    if (!System.IO.File.Exists(file))
        return;
    Process.Start(file);
}
catch (Exception)
{
}     
}

private const Int32 WM_SYSCOMMAND = 274;
private const UInt32 SC_CLOSE = 61536;
[]
private static extern bool PostMessage(IntPtr hWnd, int Msg, uint wParam, uint lParam);
[]
private static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
private void textBox_LostFocus(object sender, RoutedEventArgs e)
{
    IntPtr TouchhWnd = new IntPtr(0);
    TouchhWnd = FindWindow("IPTip_Main_Window", null);
    if (TouchhWnd == IntPtr.Zero)
        return;
    PostMessage(TouchhWnd, WM_SYSCOMMAND, SC_CLOSE, 0);
}