Android應用中怎么對網(wǎng)絡連接狀態(tài)進行監(jiān)聽

/** 
 * 
 * @author cj 判斷網(wǎng)絡工具類 
 * 
 */ 
public class NetUtil { 
  /** 
   * 沒有連接網(wǎng)絡 
   */ 
  private static final int NETWORK_NONE = -1; 
  /** 
   * 移動網(wǎng)絡 
   */ 
  private static final int NETWORK_MOBILE = 0; 
  /** 
   * 無線網(wǎng)絡 
   */ 
  private static final int NETWORK_WIFI = 1; 
  public static int getNetWorkState(Context context) { 
    // 得到連接管理器對象 
    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; 
  } 
} 
/** 
 * 自定義檢查手機網(wǎng)絡狀態(tài)是否切換的廣播接受器 
 * 
 * @author cj 
 * 
 */ 
public class NetBroadcastReceiver extends BroadcastReceiver { 
  public NetEvevt evevt = BaseActivity.evevt; 
  @Override 
  public void onReceive(Context context, Intent intent) { 
    // TODO Auto-generated method stub 
    // 如果相等的話就說明網(wǎng)絡狀態(tài)發(fā)生了變化 
    if (intent.getAction().equals(ConnectivityManager.CONNECTIVITY_ACTION)) { 
      int netWorkState = NetUtil.getNetWorkState(context); 
      // 接口回調(diào)傳過去狀態(tài)的類型 
      evevt.onNetChange(netWorkState); 
    } 
  } 
  // 自定義接口 
  public interface NetEvevt { 
    public void onNetChange(int netMobile); 
  } 
} 

<receiver android:name="cn.broadcastreceiver.NetBroadcastReceiver" > 
      <intent-filter> 
        <action android:name="android.net.conn.CONNECTIVITY_CHANGE" /> 
      </intent-filter> 
    </receiver> 
abstract public class BaseActivity extends FragmentActivity implements NetEvevt { 
  public static NetEvevt evevt; 
  /** 
   * 網(wǎng)絡類型 
   */ 
  private int netMobile; 
  @Override 
  protected void onCreate(Bundle arg0) { 
    // TODO Auto-generated method stub 
    super.onCreate(arg0); 
    evevt = this; 
    inspectNet(); 
  } 
  /** 
   * 初始化時判斷有沒有網(wǎng)絡 
   */ 
  public boolean inspectNet() { 
    this.netMobile = NetUtil.getNetWorkState(BaseActivity.this); 
    return isNetConnect(); 
    // if (netMobile == 1) { 
    // System.out.println("inspectNet：連接wifi"); 
    // } else if (netMobile == 0) { 
    // System.out.println("inspectNet:連接移動數(shù)據(jù)"); 
    // } else if (netMobile == -1) { 
    // System.out.println("inspectNet:當前沒有網(wǎng)絡"); 
    // 
    // } 
  } 
  /** 
   * 網(wǎng)絡變化之后的類型 
   */ 
  @Override 
  public void onNetChange(int netMobile) { 
    // TODO Auto-generated method stub 
    this.netMobile = netMobile; 
    isNetConnect(); 
  } 
  /** 
   * 判斷有無網(wǎng)絡 。 
   * 
   * @return true 有網(wǎng), false 沒有網(wǎng)絡. 
   */ 
  public boolean isNetConnect() { 
    if (netMobile == 1) { 
      return true; 
    } else if (netMobile == 0) { 
      return true; 
    } else if (netMobile == -1) { 
      return false; 
    } 
    return false; 
  } 
} 
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 
    //在這個判斷，根據(jù)需要做處理 
  } 
}