通过句柄或pid获取窗口的子窗口

我有主进程/窗口的句柄和pid.
我想获取进程/窗口的子级 - 只有带有标题的可视窗口.

I have handle and pid of main process / window.
I want to get the children of the process / window - only the visual windows with title.

为了实现我想要的，我使用了以下内容:

to achieve what I want, I used the following:

[DllImport("user32.dll")] private static extern int EnumWindows(EnumWindowsProc ewp, int lParam);
[DllImport("user32.dll", SetLastError = true)] static extern uint GetWindowThreadProcessId(IntPtr hWnd, out uint lpdwProcessId);
[DllImport("user32.dll")] private static extern bool IsWindowVisible(int hWnd);
[DllImport("user32.dll", CharSet = CharSet.Auto)] private static extern int GetWindowText(int hWnd, StringBuilder title, int size);


public delegate bool EnumWindowsProc(int hWnd, int lParam); //Delegate used for EnumWindows() callback function.


public void GetChildren()
{
    //Declare a callback delegate for EnumWindows() API call.
    EnumWindowsProc ewp = new EnumWindowsProc(EvalWindow);
    //Enumerate all Windows.
    EnumWindows(ewp, 0);
}

//EnumWindows CALLBACK function
private bool EvalWindow(int hWnd, int lParam)
{
    //Get the ThreadProcessId of the Window.
    IntPtr handle = (IntPtr)hWnd;
    uint currentThreadPid;
    GetWindowThreadProcessId(handle, out currentThreadPid);

    //Check if the Window is children of the current Window (if it is, it will have the same pid).
    if (currentThreadPid != _threadPid)
        return true;

    //Check if Window is Visible or not.
    if (!IsWindowVisible(hWnd))
        return true;

    //Get the Window's Title.
    StringBuilder title = new StringBuilder(256);
    GetWindowText(hWnd, title, 256);

    //Check if Window has Title.
    if (title.Length == 0)
        return true;

    //Add new Window to the _childrenhWnd.
    _childrenhWnd.Add(handle);

    return true;
}

其中 _threadPid 是父进程的 pid.

where _threadPid is the pid of the parent.

效果很好，但我觉得有一个更好的方法，而不是浏览所有打开的窗口并过滤它们.

It works great but I feel there's a better way of doing it instead of going through all the opened windows and filter them.

我说得对吗?我怎样才能做得更好?

Am I right? how can I do it better?

我看到了一些关于 EnumChildWindows 的东西，但我也能做到.

I saw something about EnumChildWindows but I could achieve the same.

基于 RaymondChen 的评论，我想澄清我所说的孩子"的意思:
1.如果您打开便签并添加便笺 - 便笺是儿童.
2. 如果你打开 Paint.NET 并按 (f5, f6, f7, f8) 打开面板- 这些是子窗口.
程序的每个窗口不是主窗口(也是对话框)，我称之为子窗口.

Based on RaymondChen comment, I want to clarify what I mean by saying "children":
1. If you open sticky notes and add notes - the notes are children.
2. If you open Paint.NET and press (f5, f6, f7, f8) to open the panels - these are child windows.
Every window of the program which is not the main (dialogs also) I call children.

编辑 2:

这是我应用汉斯方法后的代码:

Here's my code after applying Hans's method:

[DllImport("user32.dll")] static extern bool EnumThreadWindows(int dwThreadId, EnumThreadDelegate lpfn, IntPtr lParam);
[DllImport("user32.dll")] private static extern bool IsWindowVisible(int hWnd);
[DllImport("user32.dll", CharSet = CharSet.Auto)] private static extern int GetWindowText(int hWnd, StringBuilder title, int size);


delegate bool EnumThreadDelegate(IntPtr hWnd, IntPtr lParam);


public void GetChildren()
{
   foreach (ProcessThread processThread in _process.Threads)
   {
       EnumThreadWindows(processThread.Id,
        (hWnd, lParam) => 
        {
            //Check if Window is Visible or not.
            if (!IsWindowVisible((int)hWnd))
                return true;

            //Get the Window's Title.
            StringBuilder title = new StringBuilder(256);
            GetWindowText((int)hWnd, title, 256);

            //Check if Window has Title.
            if (title.Length == 0)
                return true;

            _childrenhWnd.Add(hWnd);

            return true;
        }, IntPtr.Zero);
   }
}

不需要使用 GetWindowLongPtr 因为所有拥有的窗口都必须有标题并且是可见的，否则我真的不在乎所以这些条件已经过滤了拥有的窗口.

didnt need to use GetWindowLongPtr because all the owned windows must have title and be visible else I dont really care so these conditions already filter the owned windows.