How do I get the title of the current active windo

Question

I'd like to know how to grab the Window title of the current active window (i.e. the one that has focus) using C#.

Answer 1

See example on how you can do this with full source code here:

http://www.csharphelp.com/2006/08/get-current-window-handle-and-caption-with-windows-api-in-c/

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

[DllImport("user32.dll")]
static extern int GetWindowText(IntPtr hWnd, StringBuilder text, int count);

private string GetActiveWindowTitle()
{
    const int nChars = 256;
    StringBuilder Buff = new StringBuilder(nChars);
    IntPtr handle = GetForegroundWindow();

    if (GetWindowText(handle, Buff, nChars) > 0)
    {
        return Buff.ToString();
    }
    return null;
}

---

Edited with @Doug McClean comments for better correctness.

Answer 2

If you were talking about WPF then use:

 Application.Current.Windows.OfType<Window>().SingleOrDefault(w => w.IsActive);

Answer 3

If it happens that you need the Current Active Form from your MDI application: (MDI- Multi Document Interface).

Form activForm;
activForm = Form.ActiveForm.ActiveMdiChild;

Answer 4

Based on GetForegroundWindow function | Microsoft Docs:

[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
static extern IntPtr GetForegroundWindow();

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

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

private string GetCaptionOfActiveWindow()
{
    var strTitle = string.Empty;
    var handle = GetForegroundWindow();
    // Obtain the length of the text   
    var intLength = GetWindowTextLength(handle) + 1;
    var stringBuilder = new StringBuilder(intLength);
    if (GetWindowText(handle, stringBuilder, intLength) > 0)
    {
        strTitle = stringBuilder.ToString();
    }
    return strTitle;
}

It supports UTF8 characters.

Answer 5

you can use process class it's very easy. use this namespace

using System.Diagnostics;

if you want to make a button to get active window.

private void button1_Click(object sender, EventArgs e)
    {            
       Process currentp = Process.GetCurrentProcess();
       TextBox1.Text = currentp.MainWindowTitle;  //this textbox will be filled with active window.
    }

Answer 6

Use the Windows API. Call GetForegroundWindow().

GetForegroundWindow() will give you a handle (named hWnd) to the active window.

Documentation: GetForegroundWindow function | Microsoft Docs