如何从另一个进程获得子窗口而不是子控件

我的任务是找到一种方法，使另一个应用程序出现在其他窗口的顶部(始终在顶部)。我能够使用RetrieveProcesses()函数获得具有窗口标题的进程。一旦用户选择了他们想要修改的进程，我的应用程序将调用MakeProcessOnTop或MakeProcessNormal。这两个函数都修改主应用程序的窗口。在我修改它的子节点之前，它可以正常工作。

然后我发现这在子窗口(比如outlook中的电子邮件)上不起作用，所以我开始寻找一种方法来处理子窗口。按照下面代码的编写方式，它最终会弄乱子窗口。我如何得到子窗口的句柄指针，但不是子控件?

public static class ProcessManagement
{
    [DllImport("user32.dll", SetLastError = true)]
    static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int X, int Y, int cx, int cy, SetWindowPosFlags uFlags);
    [DllImport("user32.dll", SetLastError = true)]
    static extern IntPtr SetFocus(IntPtr hWnd);
    [DllImport("user32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    static extern bool ShowWindow(IntPtr hWnd, ShowWindowCommands nCmdShow);
    [DllImport("user32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool EnumChildWindows(IntPtr hwndParent, EnumWindowsProc lpEnumFunc, IntPtr lParam);
    static readonly IntPtr HWND_TOPMOST = new IntPtr(-1);
    static readonly IntPtr HWND_NOTOPMOST = new IntPtr(-2);
    static readonly IntPtr HWND_TOP = new IntPtr(0);
    static readonly IntPtr HWND_BOTTOM = new IntPtr(1);
    public static IEnumerable<Process> RetrieveProcesses()
    {
        List<Process> returnList = new List<Process>();
        Process[] processArray = Process.GetProcesses();
        foreach (Process p in processArray)
        {
            if (!String.IsNullOrEmpty(p.MainWindowTitle))
            {
                returnList.Add(p);
            }
        }
        return returnList;
    }
    public static IntPtr GetProcessWindowHandle(int processId)
    {
        Process p = Process.GetProcessById(processId: processId);
        return p.MainWindowHandle;
    }
    public static List<IntPtr> GetProcessChildWindowHandles(IntPtr parent)
    {
        List<IntPtr> result = new List<IntPtr>();
        GCHandle listHandle = GCHandle.Alloc(result);
        try
        {
            EnumWindowsProc childProc = new EnumWindowsProc(EnumWindow);
            EnumChildWindows(parent, childProc, GCHandle.ToIntPtr(listHandle));
        }
        finally
        {
            if (listHandle.IsAllocated)
                listHandle.Free();
        }
        return result;
    }
    private static bool EnumWindow(IntPtr handle, IntPtr pointer)
    {
        GCHandle gch = GCHandle.FromIntPtr(pointer);
        List<IntPtr> list = gch.Target as List<IntPtr>;
        if (list == null)
        {
            throw new InvalidCastException("GCHandle Target could not be cast as List<IntPtr>");
        }
        list.Add(handle);
        //  You can modify this to check to see if you want to cancel the operation, then return a null here
        return true;
    }
    public static bool MakeProcessOnTop(IntPtr targetWindowHandle, bool targetChildren = true)
    {
        bool bReturn = true;
        if (!ShowWindow(targetWindowHandle, ShowWindowCommands.Minimize))
        {
            bReturn = false;
        }
        if (!ShowWindow(targetWindowHandle, ShowWindowCommands.Restore))
        {
            bReturn = false;
        }
        if (!ShowWindow(targetWindowHandle, ShowWindowCommands.ShowNoActivate))
        {
            bReturn = false;
        }
        if (!SetWindowPos(targetWindowHandle, HWND_TOPMOST, 0, 0, 0, 0, SetWindowPosFlags.SWP_NOACTIVATE | SetWindowPosFlags.SWP_NOMOVE | SetWindowPosFlags.SWP_NOSIZE))
        {
            bReturn = false;
        }
        if (targetChildren)
        {
            List<IntPtr> childProcesses = GetProcessChildWindowHandles(targetWindowHandle);
            foreach(IntPtr iPtr in childProcesses)
            {
                MakeProcessOnTop(iPtr, false);
            }
        }
        return bReturn;
    }
    public static bool MakeProcessNormal(IntPtr targetWindowHandle, bool targetChildren = true)
    {
        bool bReturn = true;
        if (!ShowWindow(targetWindowHandle, ShowWindowCommands.Minimize))
        {
            bReturn = false;
        }
        if (!ShowWindow(targetWindowHandle, ShowWindowCommands.Restore))
        {
            bReturn = false;
        }
        if (!ShowWindow(targetWindowHandle, ShowWindowCommands.ShowNoActivate))
        {
            bReturn = false;
        }
        if (!SetWindowPos(targetWindowHandle, HWND_NOTOPMOST, 0, 0, 0, 0, SetWindowPosFlags.SWP_NOACTIVATE | SetWindowPosFlags.SWP_NOMOVE | SetWindowPosFlags.SWP_NOSIZE))
        {
            bReturn = false;
        }
        if (targetChildren)
        {
            List<IntPtr> childProcesses = GetProcessChildWindowHandles(targetWindowHandle);
            foreach (IntPtr iPtr in childProcesses)
            {
                MakeProcessNormal(iPtr, false);
            }
        }
        return bReturn;
    }
}