Allowtransparency = true不呈现WPF UI

Question

我在表单应用程序中使用tabcontrol，我希望在一个选项卡中显示来自其他进程的WPF窗口。我能够使用以下代码显示WPF窗口，但如果我在WPF窗口中设置Allowtransparency = true，则不会在选项卡内部呈现它。谁能解释我为什么会这样？

    void Form1_HandleCreated(object sender, EventArgs e)
    { 
            var process = Process.Start(@"wpfWindow.exe");
            process.WaitForInputIdle();

            while (process.MainWindowHandle == IntPtr.Zero)
            {
                    Thread.Sleep(10);
            }
            SetParent(process.MainWindowHandle, tabPage1.Handle);


            SetWindowPos(process.MainWindowHandle, 0, 0, 0, (int)tabPage1.ClientSize.Width, (int)tabPage1.ClientSize.Height, WindowsConstants.SWP_NOZORDER | WindowsConstants.SWP_NOACTIVATE);
    }