Android实时监听网络状态（1）

其实手机在网络方面的的监听也比较重要，有时候我们必须实时监控这个程序的实时网络状态，android在网络断开与连接的时候都会发出广播，我们通过接收系统的广播就可以实现网络的监听。

1、添加访问网络和获取网络状态的权限

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

2、新建一个Application类并继承android.app.Application 申明变量保存网络状态

package com.javen.application;

import com.javen.netbroadcast.NetUtil;

public class Application extends android.app.Application {
    private static Application mApplication;
    public static int mNetWorkState;

    public static synchronized Application getInstance() {
        return mApplication;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        mApplication = this;
        initData();
    }

    public void initData() {
        mNetWorkState = NetUtil.getNetworkState(this);
    }
}

Application

3、新建NetBroadcastReceiver类继承BroadcastReceiver 并实现onReceive方法 在onReceive方法通知接口完成加载

package com.javen.receiver;

import java.util.ArrayList;

import com.javen.application.Application;
import com.javen.netbroadcast.NetUtil;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;

public class NetBroadcastReceiver extends BroadcastReceiver {
    public static ArrayList<netEventHandler> mListeners = new ArrayList<netEventHandler>();
    private static String NET_CHANGE_ACTION = "android.net.conn.CONNECTIVITY_CHANGE";
    @Override
    public void onReceive(Context context, Intent intent) {
        if (intent.getAction().equals(NET_CHANGE_ACTION)) {
            Application.mNetWorkState = NetUtil.getNetworkState(context);
            if (mListeners.size() > 0)// 通知接口完成加载
                for (netEventHandler handler : mListeners) {
                    handler.onNetChange();
                }
        }
    }

    public static abstract interface netEventHandler {

        public abstract void onNetChange();
    }
}

4、在应该的Activity中实现netEventHandler接口 

package com.javen.netbroadcast;

import com.javen.receiver.NetBroadcastReceiver;
import com.javen.receiver.NetBroadcastReceiver.netEventHandler;
import com.javen.ui.base.BaseActivity;

import android.os.Bundle;
import android.view.Menu;

public class MainActivity extends BaseActivity implements netEventHandler{

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        NetBroadcastReceiver.mListeners.add(this);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public void onNetChange() {
        // TODO Auto-generated method stub
        if (NetUtil.getNetworkState(this) == NetUtil.NETWORN_NONE) {
            T.showLong(this, R.string.net_err);
        }else {
            T.showLong(this, "网络可以使用");
        }
    }

}

5、判断网络的工具类

package com.javen.netbroadcast;

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo.State;

public class NetUtil {
    public static final int NETWORN_NONE = 0;
    public static final int NETWORN_WIFI = 1;
    public static final int NETWORN_MOBILE = 2;

    public static int getNetworkState(Context context) {
        ConnectivityManager connManager = (ConnectivityManager) context
                .getSystemService(Context.CONNECTIVITY_SERVICE);

        // Wifi
        State state = connManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI)
                .getState();
        if (state == State.CONNECTED || state == State.CONNECTING) {
            return NETWORN_WIFI;
        }

        // 3G
        state = connManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE)
                .getState();
        if (state == State.CONNECTED || state == State.CONNECTING) {
            return NETWORN_MOBILE;
        }
        return NETWORN_NONE;
    }
}

NetUtil