Get Application's Window Handles

Question

I'm building an app that given another app mainWindowhandle it collects information about the window state. I have no problem collecting information about child windows, but I can not access the other open windows of an application or even the menus. Is there any way of getting all window handles of an application?

Check out this working solution: http://stackoverflow.com/a/28055461/1274092 — Caffé, Jan 20 '15 at 21:30

score 17 · Accepted Answer · answered May 04 '09 at 17:01

You could do what Process.MainWindowHandle appears to do: use P/Invoke to call the EnumWindows function, which invokes a callback method for every top-level window in the system.

In your callback, call GetWindowThreadProcessId, and compare the window's process id with Process.Id; if the process ids match, add the window handle to a list.

score 11 · Answer 2 · answered May 04 '09 at 17:38

11

First, you'll have to get the windowhandle of the application's mainwindow.

 [DllImport("user32.dll", SetLastError = true)]
 static extern IntPtr FindWindow(string lpClassName, string lpWindowName);

 IntPtr hWnd = (IntPtr)FindWindow(windowName, null);

Then, you can use this handle to get all childwindows:

[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool EnumChildWindows(IntPtr hwndParent, EnumWindowsProc lpEnumFunc, IntPtr lParam);

private List<IntPtr> GetChildWindows(IntPtr parent)  
{  
    List<IntPtr> result = new List<IntPtr>();  
    GCHandle listHandle = GCHandle.Alloc(result);  
    try  
    {  
         EnumWindowProc childProc = new EnumWindowProc(EnumWindow);  
         EnumChildWindows(parent, childProc, GCHandle.ToIntPtr(listHandle));  
    }  
    finally  
    {  
         if (listHandle.IsAllocated)  
               listHandle.Free();  
    }  
    return result;  
}

answered May 04 '09 at 17:38

Mez

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1

Mez the problem isn't getting child windows, I can do that easily, what I can't do is get to other windows besides mainWindow and its childs... – user361526 May 05 '09 at 14:19
1

This works for any window, also for windows not belonging to the own application. Sorry if I misunderstood your question. – Mez May 05 '09 at 18:56
1

From where comes `EnumWindowProc`? – Matthieu Charbonnier May 18 '17 at 22:12
1

Add in a declaration for it: private delegate bool EnumWindowsProc(IntPtr hWnd, IntPtr lParam); – luka Apr 20 '18 at 08:17
2

EnumWindowProc childProc = new EnumWindowProc(EnumWindow); this get an error – luka Apr 20 '18 at 09:48

score 1 · Answer 3 · answered Nov 23 '20 at 22:16

    public void GetWindowHandles()
    {
        List<IntPtr> windowHandles = new List<IntPtr>();

        foreach (Process window in Process.GetProcesses())
        {
            window.Refresh();

            if (window.MainWindowHandle != IntPtr.Zero) 
            {
                windowHandles.Add(window.MainWindowHandle);
            }
        }
    }

Read This as to why we call the refresh method and check if the pointer is zero

Get Application's Window Handles

3 Answers3

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