Get current Active Window : Native Windows Function « Windows « C# / CSharp Tutorial

using System;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Text;

public class MainClass

    // Declare external functions.
    private static extern IntPtr GetForegroundWindow();

    private static extern int GetWindowText(IntPtr hWnd, StringBuilder text, int count);

    public static void Main() {
        int chars = 256;
        StringBuilder buff = new StringBuilder(chars);

        // Obtain the handle of the active window.
        IntPtr handle = GetForegroundWindow();

        // Update the controls.
        if (GetWindowText(handle, buff, chars) > 0)

29.10.Native Windows Function
29.10.1.Calling Native DLL Functions
29.10.2.Calling a Function with a Structure Parameter
29.10.3.Enumerate Display Monitors
29.10.4.Get Workstation information
29.10.5.Get Computer name (char * parameter)
29.10.6.Get free disk space
29.10.7.Use native windows function to read file
29.10.8.The windows version information
29.10.9.Get current Active Window
29.10.10.Writing INI file: Write Private Profile String
29.10.11.Reading INI file: Get Private Profile String
29.10.12.GetVersionEx by using kernel32.dll
29.10.13.Get computer name (StringBuilder parameter)
29.10.14.Lock work station
29.10.15.Get Monitor Information