上次发了一个文章获取windows网络状态，判断是否可以访问互联网。传送门：获取本机网络状态

这次我们监听网络状态切换，具体代码如下：

public class WindowsNetworkHelper
{
    private static Action<bool>? _NetworkStatusChangedCallback;

    /// <summary>
    /// 检查当前网络是否可访问互联网、并设置网络状态变更回调
    /// </summary>
    /// <param name="networkStatusChangedCallback"></param>
    /// <returns>true-可访问互联网；false-不可访问互联网</returns>
    public static bool CheckInternetAccessAndSetNetworkStatusChangedCallback(Action<bool> networkStatusChangedCallback)
    {
        //幅值
        _NetworkStatusChangedCallback = networkStatusChangedCallback;
        //注册网络状态变更事件
        NetworkInformation.NetworkStatusChanged -= NetworkInformation_NetworkStatusChanged;
        NetworkInformation.NetworkStatusChanged += NetworkInformation_NetworkStatusChanged;
        //返回当前网络状态
        return CheckInternetAccess();
    }

    private static void NetworkInformation_NetworkStatusChanged(object sender)
    {
        //网络状态变化，获取一次当前网络状态
        var bInternetAccess = CheckInternetAccess();
        //触发回调，把网络状态作为参数传入
        _NetworkStatusChangedCallback?.Invoke(bInternetAccess);
    }

    public static bool CheckInternetAccess()
    {
        var connectProfile = NetworkInformation.GetInternetConnectionProfile();
        if (null == connectProfile) return false;
        var networkLevel = connectProfile.GetNetworkConnectivityLevel();
        if (networkLevel == NetworkConnectivityLevel.InternetAccess)
            return true;
        else
            return false;
    }
}

调用方式：

using System;
using System.Diagnostics;
using System.Management;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Threading;
using Windows.Networking.Connectivity;

namespace ConsoleApp3
{
    internal class Program
    {
        private static void Main(string[] args)
        {

            var ret = WindowsNetworkHelper.CheckInternetAccessAndSetNetworkStatusChangedCallback(NewtworkStatusChanged);
            Console.WriteLine($"宜家网络状态是否可访问互联网:{ret}");
            Console.ReadLine();
        }

        private static void NewtworkStatusChanged(bool sender)
        {
            Console.WriteLine($"当前是否可访问互联网：{sender},是否后台线程={Thread.CurrentThread.IsBackground}");
        }
    }
}

从联网到断开网络、再连上的效果：