android - 在显示 Activity 之前，如何在android中使用来自广播接收器的数据

Question

我正在使用接收器以了解手机是否已连接到互联网。

我正在使用这段代码:

public class SearchFragment extends Fragment {

    private Boolean netOk = false;

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);

        ConnectionChangeReceiver1 netReceiver =  new ConnectionChangeReceiver1();
        IntentFilter filterNet = new IntentFilter("android.net.conn.CONNECTIVITY_CHANGE");
        getActivity().registerReceiver(netReceiver, filterNet);
    }

    @Override
    public void onResume() {
        super.onResume();

        if(netOk){
            Toast.makeText(getActivity(),"U GOT NET" , Toast.LENGTH_LONG).show();
        }else{
            Toast.makeText(getActivity(),"U DON'T GOT NET" , Toast.LENGTH_LONG).show();
        }
    }


    public class ConnectionChangeReceiver1 extends BroadcastReceiver {

        @Override
        public void onReceive(Context context, Intent intent) {

            ConnectivityManager connectivityManager = (ConnectivityManager) context
                    .getSystemService(Context.CONNECTIVITY_SERVICE);

            NetworkInfo activeNetInfo = connectivityManager
                    .getNetworkInfo(ConnectivityManager.TYPE_MOBILE);

            boolean isConnected = activeNetInfo != null
                    && activeNetInfo.isConnectedOrConnecting();

            if (isConnected){
                netOk= true;
            }else{
                netOk= false;
            }
        }
    }
}

问题是，netOk 保持错误。现在我明白了，只有在 onCreate、onStart、onResume 之后，才会调用接收器类。

所以问题是:如果我想在向用户显示 Activity 之前知道是否有互联网连接，我应该怎么做？

Answer 1

您可以试试这个以同步获取响应。

public static boolean checkInternetConnection(Context context) {

    ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
    // test for connection
    if (cm != null && cm.getActiveNetworkInfo().isConnected() 
            && cm.getActiveNetworkInfo().isAvailable()) {
        return true;
    }
    return false;
}