c# - How to read another windows from a different program

Question

I tried it with findwindow and process but it didn't work, how can I find a specific button ?

For example I have the button class AfxWnd90u and the instance 21. I want to check if this button is visible. I tried it with this code, but I couldn't find the button. I think I made a mistake with the instance.

Between I didn't use findwindow here because I experimented a little bit.

//////IMPORTANT/////////////
System.Diagnostics.Process[] move = System.Diagnostics.Process.GetProcessesByName("PartyGaming");
ArrayList save = new ArrayList();
RECT rct = new RECT();
listBox1.Items.Add(move.Length);
List<System.Diagnostics.Process> process = new List<System.Diagnostics.Process>();

// use only the process with the button AfxWnd90u21
for (int i = 0; i < move.Length;++i ) 
{
    IntPtr hCheck = FindWindowEx(move[i].MainWindowHandle, IntPtr.Zero, "AfxWnd90u21", null);
    //if button is visible
    if (hCheck != IntPtr.Zero)
        process.Add(move[i]);

    //////IMPORTANT/////////////
}

Answer 1

I believe a combination of FindWindow and SendMessage Windows API functions will give you want you want. The tricky part will be discovering the window class names, but something like WinSpy++ could help you there.

Here's a sample of how to use the API. Open Notepad.exe a few times, type in some text and then run this sample.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            List<WinText> windows = new List<WinText>();

            //find the "first" window
            IntPtr hWnd = FindWindow("notepad", null);

            while (hWnd != IntPtr.Zero)
            {
                //find the control window that has the text
                IntPtr hEdit = FindWindowEx(hWnd, IntPtr.Zero, "edit", null);

                //initialize the buffer.  using a StringBuilder here
                System.Text.StringBuilder sb = new System.Text.StringBuilder(255);  // or length from call with GETTEXTLENGTH

                //get the text from the child control
                int RetVal = SendMessage(hEdit, WM_GETTEXT, sb.Capacity, sb);

                windows.Add(new WinText() { hWnd = hWnd, Text = sb.ToString() });

                //find the next window
                hWnd = FindWindowEx(IntPtr.Zero, hWnd, "notepad", null);
            }

            //do something clever
            windows.OrderBy(x => x.Text).ToList().ForEach(y => Console.Write("{0} = {1}
", y.hWnd, y.Text));

            Console.Write("

Found {0} window(s).", windows.Count);
            Console.ReadKey();
        }

        private struct WinText
        {
            public IntPtr hWnd;
            public string Text;
        }

        const int WM_GETTEXT = 0x0D;
        const int WM_GETTEXTLENGTH = 0x0E;

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

        [DllImport("user32.dll", SetLastError = true)]
        public static extern int SendMessage(IntPtr hWnd, int msg, int Param, System.Text.StringBuilder text);

        [DllImport("user32.dll", SetLastError = true)]
        public static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, string lpszWindow);

    }
}