<receiver android:name=".NetworkConnectChangedReceiver" >     <intent-filter>         <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />         <action android:name="android.net.wifi.WIFI_STATE_CHANGED" />         <action android:name="android.net.wifi.STATE_CHANGE" />     </intent-filter></receiver>

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

IntentFilter filter = new IntentFilter();/** *     NETWORK_STATE_CHANGED_ACTION *   *  　　wifi是否连接正常 *   */filter.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION);/** *     WIFI_STATE_CHANGED_ACTION *   *     有无wifi源及各个状态间转变 *   */filter.addAction(WifiManager.WIFI_STATE_CHANGED_ACTION);/** * 　　CONNECTIVITY_ACTION *  * 　　wifi如果打开，关闭，以及连接上可用的连接都会接到监听 * 　　这个广播的最大弊端是比上边两个广播的反应要慢，如果只是要监听wifi，我觉得还是用上边两个配合比较合适   *  */filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);registerReceiver(new NetworkConnectChangedReceiver(new NetworkConnectChangedActionImp()), filter);

import android.content.Context;import android.content.Intent;public interface NetworkConnectChangedAction {        void doAfterCONNECTED(Context context , Intent intent);    void doAfterCONNECTING(Context context , Intent intent);    void doAfterDISCONNECTED (Context context , Intent intent);    void doAfterDISCONNECTING (Context context , Intent intent);    void doAfterSUSPENDED(Context context , Intent intent);    void doAfterUNKNOWN(Context context , Intent intent);}

import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.net.ConnectivityManager;import android.net.NetworkInfo;public class NetworkConnectChangedReceiver extends BroadcastReceiver {    private static NetworkConnectChangedAction action = null;        static{        action =  new NetworkConnectChangedActionImp();    }    @Override    public void onReceive(Context context, Intent intent ) {            if (ConnectivityManager.CONNECTIVITY_ACTION.equals(intent.getAction())) {            ConnectivityManager manager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);            /**             *  GPRS             */            //NetworkInfo gprs = manager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);            /**             *  INFO             */            //NetworkInfo info = intent.getParcelableExtra(ConnectivityManager.EXTRA_NETWORK_INFO);            /**             *     WIFI             */            NetworkInfo wifi = manager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);                if (wifi != null) {                if (NetworkInfo.State.CONNECTED == wifi.getState()) {                    action.doAfterCONNECTED(context, intent);                    } else if (NetworkInfo.State.CONNECTING  == wifi.getState()) {                    action.doAfterCONNECTING(context, intent);                } else if (NetworkInfo.State.DISCONNECTED  == wifi.getState()) {                    action.doAfterDISCONNECTED(context, intent);                } else if (NetworkInfo.State.DISCONNECTING  == wifi.getState()) {                    action.doAfterDISCONNECTING(context, intent);                } else if (NetworkInfo.State.SUSPENDED  == wifi.getState()) {                    action.doAfterSUSPENDED(context, intent);                } else if (NetworkInfo.State.UNKNOWN  == wifi.getState()) {                    action.doAfterUNKNOWN(context, intent);                }            }        }        }}

import android.content.Context;import android.content.Intent;public class NetworkConnectChangedActionImp implements NetworkConnectChangedAction{    @Override    public void doAfterCONNECTED(Context context, Intent intent) {}    @Override    public void doAfterCONNECTING(Context context, Intent intent) {}    @Override    public void doAfterDISCONNECTED(Context context, Intent intent) {}    @Override    public void doAfterDISCONNECTING(Context context, Intent intent) {}    @Override    public void doAfterSUSPENDED(Context context, Intent intent) {}    @Override    public void doAfterUNKNOWN(Context context, Intent intent) {}    }