How to get active window app name as shown in task manager

Question

I am trying to get the active window's name as shown in the task manager app list (using c#). I had the same issue as described here. I tried to do as they described but I have issue while the focused application is the picture library I get exception. I also tried this, but nothing gives me the results I expect. For now I use:

IntPtr handle = IntPtr.Zero;
handle = GetForegroundWindow();

const int nChars = 256;
StringBuilder Buff = new StringBuilder(nChars);
if (GetWindowText(handle, Buff, nChars) > 0)
{
    windowText = Buff.ToString();
}

and delete what is not relevant based on a table I created for most common apps, but I don't like this workaround. Is there a way to get the app name as it is in the task manager for all running app?

Answer 1

After reading a lot, I separated my code into two cases, for metro application and all other applications. My solution handle the exception I got for metro applications and exceptions I got regarding the platform. This is the code that finally worked:

[DllImport("user32.dll")]
public static extern IntPtr GetForegroundWindow();

[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
static extern int GetWindowText(IntPtr hWnd, StringBuilder lpString, int nMaxCount);

[DllImport("user32.dll")]
static extern uint GetWindowThreadProcessId(IntPtr hWnd, out uint lpdwProcessId);

public string GetActiveWindowTitle()
{
    var handle = GetForegroundWindow();
    string fileName = "";
    string name = "";
    uint pid = 0;
    GetWindowThreadProcessId(handle, out pid);

    Process p = Process.GetProcessById((int)pid);
    var processname = p.ProcessName;

    switch (processname)
    {
        case "explorer": //metro processes
        case "WWAHost":
            name = GetTitle(handle);
            return name;
        default:
            break;
    }
    string wmiQuery = string.Format("SELECT ProcessId, ExecutablePath FROM Win32_Process WHERE ProcessId LIKE '{0}'", pid.ToString());
    var pro = new ManagementObjectSearcher(wmiQuery).Get().Cast<ManagementObject>().FirstOrDefault();
    fileName = (string)pro["ExecutablePath"];
    // Get the file version
    FileVersionInfo myFileVersionInfo = FileVersionInfo.GetVersionInfo(fileName);
    // Get the file description
    name = myFileVersionInfo.FileDescription;
    if (name == "")
        name = GetTitle(handle);

 return name;
}

public string GetTitle(IntPtr handle)
{
string windowText = "";
    const int nChars = 256;
    StringBuilder Buff = new StringBuilder(nChars);
    if (GetWindowText(handle, Buff, nChars) > 0)
    {
        windowText = Buff.ToString();
    }
    return windowText;
}

Answer 2

It sounds like you need to go through each top level window (direct children of the desktop window, use EnumWindows via pinvoke http://msdn.microsoft.com/en-us/library/windows/desktop/ms633497(v=vs.85).aspx) and then call your GetWindowText pinvoke function.

EnumWindows will 'Enumerates all top-level windows on the screen by passing the handle to each window, in turn, to an application-defined callback function.'