Android利用廣播監聽裝置網路連接(斷網)的變化情況

MainActivity如下:

package cc.testnetworkchange;import android.os.Bundle;import android.app.Activity;/** * Demo描述: * 利用廣播監聽裝置網路連接的變化情況 * 亦可藉此監測到裝置是否已經斷開網路 */public class MainActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);}}

NetWorkChangeBroadcastReceiver如下:

package cc.testnetworkchange;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.net.ConnectivityManager;import android.net.NetworkInfo;import android.net.NetworkInfo.State;public class NetWorkChangeBroadcastReceiver extends BroadcastReceiver {@Overridepublic void onReceive(Context context, Intent intent) {ConnectivityManager connectivityManager=(ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);if (connectivityManager!=null) {NetworkInfo [] networkInfos=connectivityManager.getAllNetworkInfo();for (int i = 0; i < networkInfos.length; i++) {State state=networkInfos[i].getState();if (NetworkInfo.State.CONNECTED==state) {System.out.println("------------> Network is ok");return;}}}//沒有執行return,則說明當前無網路連接System.out.println("------------> Network is validate");intent.setClass(context, NetWorkErrorActivity.class);intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP|Intent.FLAG_ACTIVITY_NEW_TASK);        context.startActivity(intent);}}

NetWorkErrorActivity如下:

package cc.testnetworkchange;import android.os.Bundle;import android.app.Activity;public class NetWorkErrorActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.networkerror);}}

main.xml如下:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent" >    <TextView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="利用廣播監聽裝置網路連接的變化情況"         android:layout_centerInParent="true"   /></RelativeLayout>
networkerror.mxl如下:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent" >    <TextView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="當前沒有可用的網路"         android:layout_centerInParent="true"   /></RelativeLayout>
manifest.xml如下:
<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="cc.testnetworkchange"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk        android:minSdkVersion="8"        android:targetSdkVersion="8" />            <uses-permission android:name="android.permission.INTERNET" />    <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="cc.testnetworkchange.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>                 <!-- 註冊顯示錯誤的Activity-->        <activity android:name="cc.testnetworkchange.NetWorkErrorActivity"></activity>                <!-- 註冊廣播 -->        <receiver android:name="cc.testnetworkchange.NetWorkChangeBroadcastReceiver">            <intent-filter>                 <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />             </intent-filter>        </receiver>    </application></manifest>