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EnumDesktopWindows (user32)
 
.
Summary

C# Signature:

[DllImport("user32.dll")]
static extern bool EnumDesktopWindows(IntPtr hDesktop,
   EnumDesktopWindowsDelegate lpfn, IntPtr lParam);

User-Defined Types:

None.

Notes:

None.

Tips & Tricks:

Please add some!

Sample Code:

using System;

using System.Text;

using System.Collections;

using System.Runtime.InteropServices;

/// <summary>

/// EnumDesktopWindows Demo - shows the caption of all windows.

/// Authors: Svetlin Nakov, Martin Kulov - http://www.devbg.org/en/

/// Bulgarian Association of Software Developers

/// </summary>

public class EnumDesktopWindowsDemo

{

    const int MAXTITLE = 255;

    private static ArrayList mTitlesList;

    private delegate bool EnumDelegate(IntPtr hWnd, int lParam);

    [DllImport("user32.dll", EntryPoint="EnumDesktopWindows",
         ExactSpelling=false, CharSet=CharSet.Auto, SetLastError=true)]
    private static extern bool _EnumDesktopWindows(IntPtr hDesktop,
        EnumDelegate lpEnumCallbackFunction, IntPtr lParam);

    [DllImport("user32.dll", EntryPoint="GetWindowText",
         ExactSpelling=false, CharSet=CharSet.Auto, SetLastError=true)]
    private static extern int _GetWindowText(IntPtr hWnd,
        StringBuilder lpWindowText, int nMaxCount);

    private static bool EnumWindowsProc(IntPtr hWnd, int lParam)
    {
        string title = GetWindowText(hWnd);
        mTitlesList.Add(title);
        return true;
    }

    /// <summary>
    /// Returns the caption of a windows by given HWND identifier.
    /// </summary>
    public static string GetWindowText(IntPtr hWnd)
    {
        StringBuilder title = new StringBuilder(MAXTITLE);
        int titleLength = _GetWindowText(hWnd, title, title.Capacity + 1);
        title.Length = titleLength;

        return title.ToString();
    }

    /// <summary>
    /// Returns the caption of all desktop windows.
    /// </summary>
    public static string[] GetDesktopWindowsCaptions()
    {
        mTitlesList = new ArrayList();
        EnumDelegate enumfunc = new EnumDelegate(EnumWindowsProc);
        IntPtr hDesktop = IntPtr.Zero; // current desktop
        bool success = _EnumDesktopWindows(hDesktop, enumfunc, IntPtr.Zero);

        if (success)
        {
            // Copy the result to string array
            string[] titles = new string[mTitlesList.Count];
            mTitlesList.CopyTo(titles);
            return titles;
        }
        else
        {
            // Get the last Win32 error code
            int errorCode = Marshal.GetLastWin32Error();

            string errorMessage = String.Format(
                "EnumDesktopWindows failed with code {0}.", errorCode);
            throw new Exception(errorMessage);
        }
    }

    static void Main()
    {
        string[] desktopWindowsCaptions = GetDesktopWindowsCaptions();
        foreach (string caption in desktopWindowsCaptions)
        {
            Console.WriteLine(caption);
        }
    }

}

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