C# List running applications which have a GUI

Question

How could I list all running applications which have a GUI in C#? I am trying to make some sort of a taskbar, so I have to know what processes are running. I can't list all processes of course, because that would be a total disaster. My idea is to only list processes with a gui, because that seems like what's happening in the "stock" taskbar.

Would a solution that simply lists all the windows on the desktop be ok? — Emond, Aug 06 '17 at 18:45
If it lists the minimized ones as well, then it would be perfect. If only the ones that are "visible", then it's not really the answer, but it would be also appreciated because I will need that later. — Máté Varga, Aug 06 '17 at 18:53
See https://stackoverflow.com/questions/7268302/get-the-titles-of-all-open-windows and https://stackoverflow.com/questions/1032933/enumerate-all-window-handles-on-desktop — Emond, Aug 06 '17 at 18:57

score 0 · Answer 1 · answered Aug 06 '17 at 18:43

You can list all processes that have a main window:

static IEnumerable<Process> WindowProcesses()
{
    foreach(var proc in Process.GetProcesses())
    {
        if(proc.MainWindowHandle != IntPtr.Zero)
        {
            yield return proc;
        }
    }
}

This will enumerate all processes that have a main window, but may not necessarily list all processes that have any visible windows (e.g. services). For that, you need to P/Invoke EnumWindows and GetWindowThreadProcessId.

Ghulam Mohayudin · Accepted Answer · 2017-08-06T19:04:48.727

This code will fill a dropdown and set get it on foreground by selection, you can do it like this

    [DllImport("User32.dll")]
    static extern bool ShowWindow(IntPtr hWnd, uint nCmdShow);
    [DllImport("User32.dll")]
    private static extern bool SetForegroundWindow(IntPtr hWnd);

    private void ListTask()
    {
        Process[] processes = Process.GetProcesses();
        foreach (Process process in Process.GetProcesses().
                                     Where(p => !string.IsNullOrEmpty(p.MainWindowTitle)).ToList())
            listBox1.Items.Add(process.ProcessName);
    }

    private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
    {
        Process p = new Process();
        string name = listBox1.SelectedItem.ToString();
        p = Process.GetProcessesByName(name)[0];
        const uint SWP_SHOWWINDOW = 0x0001;
        ShowWindow(p.MainWindowHandle, SWP_SHOWWINDOW);
        SetForegroundWindow(p.MainWindowHandle);
        p.Dispose();
    }

1) Enumerates all processes, while the questioner only wanted those that have a GUI. 2) Creates a rendundant instance at `new Process()`. 3) `GetProcessesByName` may be ambiguous and return an incorrect process. — IS4, Aug 06 '17 at 18:52
Why do you check for the title? What if the window had an empty title? — IS4, Aug 06 '17 at 23:58

C# List running applications which have a GUI

2 Answers2