我正在开发Xamarin Android应用程序。在继续我的下一个片段之前,我想检查 Internet连接并告知用户有关它的信息?我该如何实现呢?如何在用户开启互联网后刷新整个片段? 任何建议或意见将不胜感激!
答案 0 :(得分:11)
要获取网络状态,您可以在活动中使用以下方法:
public bool IsOnline()
{
var cm = (ConnectivityManager)GetSystemService(ConnectivityService);
return cm.ActiveNetworkInfo == null ? false : cm.ActiveNetworkInfo.IsConnected;
}
如果我从这句话中正确地理解你:And how to refresh whole fragment after user switch-on the internet
,你想要在连接状态发生任何变化时检测到,因此你绝对需要使用broadcast receivers。
首先,您应该使用名为ConnectionStatusChanged
的简单事件实现广播接收器,如下所示:
[BroadcastReceiver()]
public class NetworkStatusBroadcastReceiver : BroadcastReceiver
{
public event EventHandler ConnectionStatusChanged;
public override void OnReceive(Context context, Intent intent)
{
if (ConnectionStatusChanged != null)
ConnectionStatusChanged(this, EventArgs.Empty);
}
}
然后在您的活动中(例如,在OnCreate()
方法中,无关紧要)创建该接收器的实例并注册它:
var _broadcastReceiver = new NetworkStatusBroadcastReceiver();
_broadcastReceiver.ConnectionStatusChanged += OnNetworkStatusChanged;
Application.Context.RegisterReceiver(_broadcastReceiver,
new IntentFilter(ConnectivityManager.ConnectivityAction));
以下是事件处理程序的主体:
private void OnNetworkStatusChanged(object sender, EventArgs e)
{
if(IsOnline()){
Toast.MakeText(this, "Network Activated", ToastLength.Short).Show();
// refresh content fragment.
}
}
简而言之,NetworkStatusBroadcastReceiver
收到设备网络状态的任何变化,并调用ConnectionStatusChanged
(当用户启用数据流量或WiFi连接时),然后您捕获该事件,使用IsOnline()
方法检查网络状态。非常简单。
答案 1 :(得分:4)
您可以使用MVVMCross插件:Connectivity
它会暴露一个布尔值
/// <summary>
/// Gets if there is an active internet connection
/// </summary>
bool IsConnected { get; }
和改变状态的代表
/// <summary>
/// Event handler when connection changes
/// </summary>
event ConnectivityChangedEventHandler ConnectivityChanged;
答案 2 :(得分:1)
试试这个:
NetworkStatus internetStatus = Reachability.InternetConnectionStatus();
if(!Reachability.IsHostReachable("http://google.com")) {
// Put alternative content/message here
}
else
{
// Put Internet Required Code here
}