22 网络状态

• 权限

<!--网络状态的权限  -->
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

• 意图

public static final String CONNECTIVITY_ACTION = "android.net.conn.CONNECTIVITY_CHANGE";

结构：

清单文件:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.qf.day22_broadcastreceiver_demo7"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="18" />

    <!--网络状态的权限  -->
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.qf.day22_broadcastreceiver_demo7.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

MainActivity.java

package com.qf.day22_broadcastreceiver_demo7;

import android.net.ConnectivityManager;
import android.os.Bundle;
import android.app.Activity;
import android.content.IntentFilter;
import android.view.Menu;

public class MainActivity extends Activity {

    private MyNetWorkStateReceiver myNetWorkStateReceiver =  new MyNetWorkStateReceiver();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        IntentFilter intentFilter = new IntentFilter();
        //网络的监听Action
        intentFilter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
        registerReceiver(myNetWorkStateReceiver, intentFilter);
    }



}

MyNetWorkStateReceiver.java

package com.qf.day22_broadcastreceiver_demo7;

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

public class MyNetWorkStateReceiver extends BroadcastReceiver{

    @Override
    public void onReceive(Context context, Intent intent) {
        // TODO Auto-generated method stub
        //网络管理者对象
        ConnectivityManager manager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);

        NetworkInfo info = manager.getActiveNetworkInfo();

        if(info ==null){
            Log.e("AAA", "网络异常");
        }else{
            if(info.isConnected()){//是否连接
                Log.e("AAA", "网络正常");
            }else{
                //比如你链接wifi 但是不能上网
                Log.e("AAA", "网络无链接");
            }
        }
    }

}