c# - 如何确定互联网连接是否可用？

Question

如何确定 Windows 商店应用程序中是否有 Internet 连接？

Answer 1

您可以使用NetworkInformation该类来检测它；此示例代码添加了一个事件处理程序，每次连接状态更改时都会调用该处理程序；

NetworkInformation.NetworkStatusChanged += 
    NetworkInformation_NetworkStatusChanged; // Listen to connectivity changes

static void NetworkInformation_NetworkStatusChanged(object sender)
{
    ConnectionProfile profile = 
        NetworkInformation.GetInternetConnectionProfile();

    if ((profile != null) && profile.GetNetworkConnectivityLevel() >=
                NetworkConnectivityLevel.InternetAccess)
    {
        // We have Internet, all is golden
    }
}

当然，如果您只想检测一次而不是在它更改时收到通知，您可以从上面进行检查，而无需监听 change 事件。

Answer 2

using Windows.Networking.Connectivity;      

public static bool IsInternetConnected()
{
    ConnectionProfile connections = NetworkInformation.GetInternetConnectionProfile();
    bool internet = (connections != null) && 
        (connections.GetNetworkConnectivityLevel() == NetworkConnectivityLevel.InternetAccess);
            return internet;
}

Answer 3

刚刚编写了异步函数来做到这一点：

    private void myPingCompletedCallback(object sender, PingCompletedEventArgs e)
    {
        if (e.Cancelled)
            return;

        if (e.Error != null)
            return;

        if (e.Reply.Status == IPStatus.Success)
        {
            //ok connected to internet, do something
        }
    }

    private void checkInternet()
    {
        Ping myPing = new Ping();
        myPing.PingCompleted += new PingCompletedEventHandler(myPingCompletedCallback);
        byte[] buffer = new byte[32];
        int timeout = 1000;
        PingOptions options = new PingOptions(64, true);
        try
        {
            myPing.SendAsync("google.com", timeout, buffer, options);
        }
        catch
        {
        }
    }