在没有轮询的情况下使用C#检测活动窗口已更改

using System;
using System.Runtime.InteropServices;

public class WindowActivityDetector
{
    private const int WH_FOREGROUNDIDLE = 11;
    private const int WM_ACTIVATE = 6;

    private delegate IntPtr HookProc(int code, IntPtr wParam, IntPtr lParam);

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    private static extern IntPtr SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hMod, uint dwThreadId);

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    private static extern bool UnhookWindowsHookEx(IntPtr hhk);

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode, IntPtr wParam, IntPtr lParam);

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

    private static IntPtr hookId = IntPtr.Zero;

    public static void StartMonitoring()
    {
        HookProc hookProc = new HookProc(WindowActivityCallback);
        hookId = SetWindowsHookEx(WH_FOREGROUNDIDLE, hookProc, IntPtr.Zero, 0);
    }

    public static void StopMonitoring()
    {
        UnhookWindowsHookEx(hookId);
    }

    private static IntPtr WindowActivityCallback(int code, IntPtr wParam, IntPtr lParam)
    {
        if (code >= 0 && wParam.ToInt32() == WM_ACTIVATE)
        {
            IntPtr activeWindowHandle = GetForegroundWindow();
            // 在这里可以进行对活动窗口的处理
            Console.WriteLine("活动窗口已更改，句柄为：" + activeWindowHandle.ToString());
        }

        return CallNextHookEx(hookId, code, wParam, lParam);
    }
}

public class Program
{
    public static void Main(string[] args)
    {
        WindowActivityDetector.StartMonitoring();

        // 程序继续执行其他逻辑
        Console.WriteLine("正在监视窗口活动改变...");

        // 按下任意键停止监视
        Console.ReadKey();

        WindowActivityDetector.StopMonitoring();
    }
}