利用廣播接收者監聽Android系統網絡變化

1.自定義廣播接收者

package com.onetoo.www.onetoo.receiver;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.util.Log;

/**
 * Created by longShun on 2017/2/17.
 * desc 網絡相關接收者
 */
public class NetBroadCastReceiver extends BroadcastReceiver {

    private static final String TAG = "NetBroadCastReceiver";

    @Override
    public void onReceive(Context context, Intent intent) {
        //如果是在開啓wifi連接和有網絡狀態下
        if(ConnectivityManager.CONNECTIVITY_ACTION.equals(intent.getAction())){
            ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkInfo networkInfo = cm.getActiveNetworkInfo();
            if (networkInfo != null && networkInfo.isAvailable()) {
                Log.d(TAG, "onReceive:網絡打開 ");
                //todo...相應處理
            }
            else {
                Log.d(TAG, "onReceive:網絡關閉 ");
            }
        }
    }
}

2.代碼中動態註冊

private NetBroadCastReceiver netBroadCastReceiver;

 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        //註冊網絡監聽
        netBroadCastReceiver = new NetBroadCastReceiver();
        IntentFilter intentFiler = new IntentFilter();
        //"android.net.conn.CONNECTIVITY_CHANGE"這個是網絡變化時系統發出的廣播                 
        intentFiler.addAction("android.net.conn.CONNECTIVITY_CHANGE");
        registerReceiver(netBroadCastReceiver, intentFiler);

    }

@Override
    protected void onDestroy() {
        super.onDestroy();
        //解除註冊
        unregisterReceiver(netBroadCastReceiver);
    }