当窗体的MdiParent属性发生更改时，在面板中运行exe终止

我有一个表单（ToolForm），其中包含一个包含企业应用程序的面板 .

使用表单和托管应用程序一切正常，直到我将ToolForm的MdiParent属性设置为MdiContainer表单（MainAppForm） .

每当我设置MdiParent时，托管的应用程序只会在没有提示的情况下终止，并且在任务管理器中检查过，该过程确实被杀死了 .

无论如何设置ToolForm的MdiParent而不杀死托管应用程序？

Sample code here.

public partial class MainAppForm : Form
{
    public MainAppForm()
    {
        InitializeComponent();
        // Set additional form properties
        this.IsMdiContainer = true;
        ToolForm tf = new ToolForm();
        tf.Show(); // This would work fine
        tf.MdiParent = this; // hosted notepad.exe would just terminate here
    }
}

public partial class ToolForm : Form
{

    [DllImport("user32.dll", SetLastError = true)]
    private static extern long SetParent(IntPtr hWndChild, IntPtr hWndNewParent);

    [DllImport("user32.dll", EntryPoint = "GetWindowLongA", SetLastError = true)]
    private static extern long GetWindowLong(IntPtr hwnd, int nIndex);

    [DllImport("user32.dll", EntryPoint = "SetWindowLongA", SetLastError = true)]
    private static extern long SetWindowLong(IntPtr hwnd, int nIndex, long dwNewLong);

    [DllImport("user32.dll", SetLastError = true)]
    private static extern long SetWindowPos(IntPtr hwnd, long hWndInsertAfter, long x, long y, long cx, long cy, long wFlags);

    [DllImport("user32.dll", SetLastError = true)]
    private static extern bool MoveWindow(IntPtr hwnd, int x, int y, int cx, int cy, bool repaint);


    public ToolForm()
    {
        InitializeComponent();
        HostTestApplication();
    }

    public void HostTestApplication()
    {

        // Start the process
        IntPtr appWin = IntPtr.Zero;
        Process p = System.Diagnostics.Process.Start("notepad");

        // Wait for process to be created and enter idle condition
        p.WaitForInputIdle();
        p.EnableRaisingEvents = true;
        p.Exited += (s, ee) => Console.WriteLine("Process Exited!");
        while (p.Handle == IntPtr.Zero)
        {
            System.Threading.Thread.Sleep(100);
            p.Refresh();
        }

        // Get the main handle
        appWin = p.MainWindowHandle;

        // Put it into this form
        SetParent(appWin, panel1.Handle);

        // Move the window to overlay it on this window
        MoveWindow(appWin, -2, -22, this.Width, this.Height, true);

        // Resize window when panel size changed
        panel1.Resize += (s, e) => MoveWindow(appWin, -2, -22, this.Width, this.Height, true);

    }
}