84RR1573R 84RR1573R - 9 days ago 4
C# Question

C# get child handles using FindWindowEx by name and ordinal number

According to http://msdn.microsoft.com/en-us/library/ms633500(v=vs.85).aspx I define FindWindowEx function.

using System.Runtime.InteropServices;

[DllImport("user32.dll", CharSet=CharSet.Unicode)]
static extern IntPtr FindWindowEx(IntPtr parentHandle, IntPtr childAfter, string lclassName, string windowTitle);


Now I am able to find first handle of "Button" control (get name from Spy++) setting childAfter as IntPtr.Zero.

IntPtr hWndParent = new IntPtr(2032496); // providing parent window handle
IntPtr hWndButton = FindWindowEx(hWndParent, IntPtr.Zero, "Button", string.Empty);


How to get second, third or any handle of "Button" control inside that parent window? The fact is, button titles may vary, so I cannot find them directly by name defining fourth parameter.

Answer
static IntPtr FindWindowByIndex(IntPtr hWndParent, int index)
{
    if (index == 0)
        return hWndParent;
    else
    {
        int ct = 0;
        IntPtr result = IntPtr.Zero;
        do
        {
            result = FindWindowEx(hWndParent, result, "Button", null);
            if (result != IntPtr.Zero)
                ++ct;
        }
        while (ct < index && result != IntPtr.Zero);
        return result;
    }
}

Use like:

IntPtr hWndThirdButton = FindWindowByIndex(hWnd, 3); // handle of third "Button" as shown in Spy++
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