仅在数据或 wifi 断开连接时收到通知

Question

大家好，我正在构建一个应用程序，我只想在设备失去连接（无论是移动数据还是 wifi）时通知用户。

到目前为止我用过这个方法：

private void setupReceiver() {
        CheckNetworkStatusReceiver receiver = new CheckNetworkStatusReceiver();
        registerReceiver(receiver, new IntentFilter("android.net.conn.CONNECTIVITY_CHANGE"));
    }

和我的接收器：

public class CheckNetworkStatusReceiver extends BroadcastReceiver{

    @Override
    public void onReceive(Context context, Intent intent) {
        if (intent != null){
            Log.e("Action ",intent.getAction());
            if(intent.getAction().equalsIgnoreCase("android.net.conn.CONNECTIVITY_CHANGE")) {
                Toast.makeText(context, "Connection changed", Toast.LENGTH_SHORT).show();
            }
        }
    }
}

它工作正常，但问题是 toast 在连接到网络时也会显示，这是我不想要的。我只希望吐司在断开连接时显示。

有什么想法吗？

Answer 1

在显示 toast 之前检查连接是否可用，类似这样

 if(!isNetworkAvailable()){
Toast.makeText(context, "Connection changed", Toast.LENGTH_SHORT).show();
 }




private boolean isNetworkAvailable() {
 ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
 NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
 return activeNetworkInfo != null; 
}

编辑

为了安全起见，使用这个

private boolean isNetworkAvailable() {
ConnectivityManager connectivityManager 
      = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
return activeNetworkInfo != null && activeNetworkInfo.isConnected();
}

Answer 2

您可以这样检查网络连接：

    public static boolean isNetworkConnected() {
    ConnectivityManager cm = (ConnectivityManager) MBankApplication.appContext.getSystemService
            (Context.CONNECTIVITY_SERVICE);

    NetworkInfo wifiNetwork = cm.getNetworkInfo(1);
    if (wifiNetwork != null && wifiNetwork.isConnected()) {
        return true;
    }
    NetworkInfo mobileNetwork = cm.getNetworkInfo(0);
    if (mobileNetwork != null && mobileNetwork.isConnected()) {
        return true;
    }
    NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
    if (activeNetwork == null || !activeNetwork.isConnected()) {
        return false;
    }
    return true;
}

然后展示你的吐司

    if(!isNetworkConnected()){
        Toast.makeText(context, "Connection changed", Toast.LENGTH_SHORT).show();
    }

仅在数据或 wifi 断开连接时收到通知

Get notified only when data or wifi is disconnected

android

broadcastreceiver

android-connectivitymanager