在Android上监听网络状态的变更

  开发过程中经常会遇到一种需求，在你的Activity中需要获得网络连接的状态，以便确认下一步的流程，之前设计过一个复杂的方法，后来发现每次网络状态发生变化了都会发广播出来，广播这是个好东西，有了广播，我们就可以灵活的去处理了。

    当然，首先要加权限 

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

这样，我们写receiver就可以了。

<receiver      android:name="NetworkReceiver">      <intent-filter>          <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />      </intent-filter>    </receiver> 

public class NetworkReceiver extends BroadcastReceiver {        protected Context    mContext;        @Override      public void onReceive(Context context, Intent intent) {          mContext = context;          // 第一种          ConnectivityManager connectivityManager = (ConnectivityManager) context                  .getSystemService(Context.CONNECTIVITY_SERVICE);          NetworkInfo activeNetInfo = connectivityManager.getActiveNetworkInfo();          NetworkInfo mobileNetInfo = connectivityManager                  .getNetworkInfo(ConnectivityManager.TYPE_MOBILE);          showToast("Active Network Type", activeNetInfo);          showToast("Mobile Network Type", mobileNetInfo);          // 第二种          NetworkInfo networkInfo = intent                  .getParcelableExtra(ConnectivityManager.EXTRA_NETWORK_INFO);          String extraInfo = intent                  .getStringExtra(ConnectivityManager.EXTRA_EXTRA_INFO);          boolean isFailOver = intent.getBooleanExtra(                  ConnectivityManager.EXTRA_IS_FAILOVER, false);          boolean noConnectivity = intent.getBooleanExtra(                  ConnectivityManager.EXTRA_NO_CONNECTIVITY, false);          NetworkInfo otherNetworkInfo = intent                  .getParcelableExtra(ConnectivityManager.EXTRA_OTHER_NETWORK_INFO);          String reason = intent.getStringExtra(ConnectivityManager.EXTRA_REASON);          //          showToast("networkInfo", networkInfo);          showToast("extraInfo", extraInfo);          showToast("isFailOver", isFailOver);          showToast("noConnectivity", noConnectivity);          showToast("otherNetworkInfo", otherNetworkInfo);          showToast("reason", reason);      }        public void showToast(String info, Object object) {          if (object == null) {              return;          }          Toast.makeText(mContext, info + " : " + object.toString(), 0).show();      }    }