How do I get the title of the current active window using c#?

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#.

Effector

Were you trying to determine which window within your application has focus or which window of any application has focus? – Cultured

this is relevant #2423734 so if you wanted a button click to do it then it's worth making sure your form doesn't take focus. – Episcopal

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.

Holiness

Don't forget to be a good citizen. blogs.msdn.com/oldnewthing/archive/2007/07/27/4072156.aspx and blogs.msdn.com/oldnewthing/archive/2008/10/06/8969399.aspx have relevant info. – Summerlin

a newb note, to get it to run, using System.Runtime.InteropServices; and re where to put the dll import and static extern lines. pasting it within the class – Episcopal

@smink How get Active foreground window for specific user (let's say process runs as service). – Jibe

Site you've linked to isn't available. Here is (possibly) web archive of it: web.archive.org/web/20150814043810/http://www.csharphelp.com/… – Horde

Also, I want my app to be notified every time foreground window will change. Is there any event for that? – Horde

this works perfectly when the text is in english. but when the text is hebrew I get question marks instead of the hebrew text. is there a way around that? – Biosynthesis

Can I use this to access the SaveFileDialog, I want to access the dialog window and want to set its file location, filename and click the save button programmatically.. – Stake

Answer 2

If you were talking about WPF then use:

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

Coralloid

If the entire application isn't active (another program has focus), then no window will have IsActive set to true. – Vaunt

Actually that could be wrong, in my case I was trying to access the Window array on a non-UI thread. However, also see this in case I am still right: social.msdn.microsoft.com/Forums/vstudio/en-US/… – Vaunt

Answer 3

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.

Bb

Answer 4

Loop over Application.Current.Windows[] and find the one with IsActive == true.

Deventer

Wouldn't this only work for the windows in the current .Net application? I think d4nt wants to get the title of the current active window on the desktop, no matter what application it belongs to. – Echinate

Answer 5

Use the Windows API. Call GetForegroundWindow().

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

Documentation: GetForegroundWindow function | Microsoft Docs

Mazy

Answer 6

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

Form activForm;
activForm = Form.ActiveForm.ActiveMdiChild;

Resolutive

Answer 7

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.
    }

Autocracy

This is wrong. It will show the title of your program not of the current active window. – Risible