想做一个断网时显示页面。从网上找到一个挺好的帖子,然后就试着写了一下真的还不错。
大体思路:网络变化时系统会发出广播,然后监听这个广播,对activity进行通知。
在清单文件中添加权限<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission>
写一个工具类来监听网络变化:
- public class NetUtil {
- /**
- * 没有连接网络
- */
- private static final int NETWORK_NONE = -1;
- /**
- * 移动网络
- */
- private static final int NETWORK_MOBILE = 0;
- /**
- * 无线网络
- */
- private static final int NETWORK_WIFI = 1;
- public static int getNetWorkState(Context context) {
- // 得到连接管理器对象
- ConnectivityManager connectivityManager = (ConnectivityManager) context
- .getSystemService(Context.CONNECTIVITY_SERVICE);
- NetworkInfo activeNetworkInfo = connectivityManager
- .getActiveNetworkInfo();
- if (activeNetworkInfo != null && activeNetworkInfo.isConnected()) {
- if (activeNetworkInfo.getType() == (ConnectivityManager.TYPE_WIFI)) {
- return NETWORK_WIFI;
- } else if (activeNetworkInfo.getType() == (ConnectivityManager.TYPE_MOBILE)) {
- return NETWORK_MOBILE;
- }
- } else {
- return NETWORK_NONE;
- }
- return NETWORK_NONE;
- }
- }
写一个类继承
BroadcastReceiver 自定义接口来做通知
- public class NetBroadcastReceiver extends BroadcastReceiver {
- public NetEvevt evevt = BaseActivity.evevt;
- @Override
- public void onReceive(Context context, Intent intent) {
- // TODO Auto-generated method stub
- // 如果相等的话就说明网络状态发生了变化
- if (intent.getAction().equals(ConnectivityManager.CONNECTIVITY_ACTION)) {
- int netWorkState = NetUtil.getNetWorkState(context);
- // 接口回调传过去状态的类型
- evevt.onNetChange(netWorkState);
- }
- }
- // 自定义接口
- public interface NetEvevt {
- public void onNetChange(int netMobile);
- }
- }
- abstract public class BaseActivity extends FragmentActivity implements NetEvevt {
- public static NetEvevt evevt;
- /**
- * 网络类型
- */
- private int netMobile;
- @Override
- protected void onCreate(Bundle arg0) {
- // TODO Auto-generated method stub
- super.onCreate(arg0);
- evevt = this;
- inspectNet();
- }
- /**
- * 初始化时判断有没有网络
- */
- public boolean inspectNet() {
- this.netMobile = NetUtil.getNetWorkState(BaseActivity.this);
- return isNetConnect();
- }
- /**
- * 网络变化之后的类型
- */
- @Override
- public void onNetChange(int netMobile) {
- // TODO Auto-generated method stub
- this.netMobile = netMobile;
- isNetConnect();
- }
- /**
- * 判断有无网络 。
- *
- * @return true 有网, false 没有网络.
- */
- public boolean isNetConnect() {
- if (netMobile == 1) {
- return true;
- } else if (netMobile == 0) {
- return true;
- } else if (netMobile == -1) {
- return false;
- }
- return false;
- }
- }
最后别忘了,在清单文件中注册
- <receiver android:name="cn.broadcastreceiver.NetBroadcastReceiver" >
- <intent-filter>
- <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
- </intent-filter>
- </receiver>
- public class MainActivity extends BaseActivity {
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.activity_main);
- }
- @Override
- public void onNetChange(int netMobile) {
- // TODO Auto-generated method stub
- //在这个判断,根据需要做处理
- }
- }
原文转载至http://blog.csdn.net/mxiaoyem/article/details/50708052