Android网络状态检测

/*
  * 判读当前网络是否可用
  * */
 private  boolean isNetworkAvailable() {     
     Context context = mActivity.getApplicationContext();     
     ConnectivityManager connectivity = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);     
     if (connectivity == null) {     
        return false;     
     } else {     
        NetworkInfo[] info = connectivity.getAllNetworkInfo();     
        if (info != null) {     
           for (int i = 0; i < info.length; i++) {     
              if (info[i].getState() == NetworkInfo.State.CONNECTED) {     
                 return true;     
              }     
           }     
        }     
     }     
     return false;     
  }