Android开发之使用广播监听网络状态变化

 

我们经常需要判断网络状态的变化，如有无网络，所以需要监听网络状态的变化，比如网络断开，网络连接给予友好提示。如何监听网络状态的变化呢，最近工作中需要用到这个，于是就用广播机制来实现了网络状态的监听。

使用广播机制来监听网络状态主要涉及到以下几点：

1.需要自己编写个网络广播接收器，该接收器继承BroadcastReceiver类，用来接收系统发出的广播。比如我自己写了个NetStatusReceiver广播接收器。代码如下：

package com.log.system;



import android.content.BroadcastReceiver;

import android.content.Context;

import android.content.Intent;

import android.net.ConnectivityManager;

import android.net.NetworkInfo;

import android.widget.Toast;





public class NetStatusReceiver  extends BroadcastReceiver{



    public static final int NETSTATUS_INAVAILABLE = 0;

    public static final int NETSTATUS_WIFI = 1;

    public static final int NETSTATUS_MOBILE = 2;

    public static int netStatus = 0;

    public static boolean updateSuccess = false;

    private INetStatusListener mINetStatusListener;



    public void onReceive(Context context, Intent intent) {

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

        NetworkInfo mobileNetInfo = cm.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);

        NetworkInfo wifiNetInfo = cm.getNetworkInfo(ConnectivityManager.TYPE_WIFI);

        NetworkInfo allNetInfo = cm.getActiveNetworkInfo();



        if (allNetInfo == null) {

            if (mobileNetInfo != null && (mobileNetInfo.isConnected() || mobileNetInfo.isConnectedOrConnecting())) {

                netStatus = NETSTATUS_MOBILE;

            } else if (wifiNetInfo != null && wifiNetInfo.isConnected() || wifiNetInfo.isConnectedOrConnecting()) {

                netStatus = NETSTATUS_WIFI;

            } else {

                netStatus = NETSTATUS_INAVAILABLE;

            }

        } else {

            if (allNetInfo.isConnected() || allNetInfo.isConnectedOrConnecting()) {

                if (mobileNetInfo.isConnected() || mobileNetInfo.isConnectedOrConnecting()) {

                    netStatus = NETSTATUS_MOBILE;

                } else {

                    netStatus = NETSTATUS_WIFI;

                }

            } else {

                netStatus = NETSTATUS_INAVAILABLE;

            }

        }

        if(mINetStatusListener != null){

            mINetStatusListener.getNetState(netStatus);

        }

//        if (netStatus == NETSTATUS_INAVAILABLE) {

//            Toast.makeText(context, "网络未连接",Toast.LENGTH_SHORT).show();

//        } else if (netStatus == NETSTATUS_MOBILE) {

//            Toast.makeText(context, "网络处于移动网络",Toast.LENGTH_SHORT).show();

//        } else {

//            Toast.makeText(context, "网络处于Wifi网络",Toast.LENGTH_SHORT).show();

//        }

    }

    

    public void setNetStateListener(INetStatusListener listener){

        mINetStatusListener = listener;

    }

    

    public interface INetStatusListener{

        public void getNetState(int state);

    }

}

 

2.注册广播接收器

首先new一个广播接收器，然后对该接收器进行注册，也就是注册广播，然后并设置监听器。注册广播和设置监听的实现如下：

netReceiver = new NetStatusReceiver();
setRegisterReceiver(netReceiver);
setNetListener();

对应的具体方法实现代码如下：

public void setRegisterReceiver(NetStatusReceiver netReceiver){

        IntentFilter filter = new IntentFilter();

        filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);

        registerReceiver(netReceiver, filter);

    }

    public void setNetListener(){

        netReceiver.setNetStateListener(new INetStatusListener() {

            

            @Override

            public void getNetState(int state) {

                // TODO Auto-generated method stub

                if (state == NetStatusReceiver.NETSTATUS_INAVAILABLE) {

                    Toast.makeText(getBaseContext(), "网络未连接",

                            Toast.LENGTH_SHORT).show();

                } else {

                    Toast.makeText(getBaseContext(), "网络已经连接",

                            Toast.LENGTH_SHORT).show();

                }

            }

        });

    }

 

3.为了要获取网络的状态，需要在manifest文件中设置相关权限，即配置：

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