How to get active window that is not part of my application?

Question

How can I get the Window Title that the user currently have focus on? I'm making a program that runs with another Window, and if the user does not have focus on that window I find no reason for my program to keep updating.

So how can I determine what window the user have focus on?

I did try to look into

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

but I seems I can only use that if the Window is part of my application which is it not.

Melton

Did you read the documentation for that function? If so, what part was not clear? If not, why not? – Nacred

Answer 1

Check this code:

[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;
}

Contraband

Got it working now, thanks. WIll accept it when I can. – Melton

Sorry it took so long to accept the answer, done it now. – Melton

Answer 2

Use GetForegroundWindow to retrieve the handle of the focused window and GetWindowText to get the window title.

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

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

static void Main() { 
     StringBuilder builder = new StringBuilder(255) ; 
     GetWindowText(GetForegroundWindow(), builder, 255) ; 

     Console.WriteLine(builder) ; 
} 

Domineca

For some reason this will the lenght of the builder will be 0. – Melton