Ping超时在Xamarin android表单应用程序中不起作用

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

if (ContextCompat.CheckSelfPermission(this, Manifest.Permission.Internet) != Permission.Granted)
{
    ActivityCompat.RequestPermissions(this, new string[] { Manifest.Permission.Internet }, REQUEST_INTERNET);
}

private async Task PingHostAsync(string host)
{
    var ping = new Ping();
    try
    {
        var reply = await ping.SendPingAsync(host);
        if (reply.Status == IPStatus.Success)
        {
            // Ping 成功
        }
        else
        {
            // Ping 失败
        }
    }
    catch (Exception ex)
    {
        // 处理异常
    }
}

ConnectivityManager cm = (ConnectivityManager)GetSystemService(Context.ConnectivityService);
NetworkInfo activeNetwork = cm.ActiveNetworkInfo;
bool isConnected = activeNetwork != null && activeNetwork.IsConnectedOrConnecting;

try
{
    // Ping 操作代码
}
catch (Exception ex)
{
    Log.Error("PingError", ex.Message);
}