下面的方法返回false表示网络不通    // 检测网络   public static boolean checkNetworkAvailable(Context context) {    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) {        NetworkInfo netWorkInfo = info[i];        if (netWorkInfo.getType() == ConnectivityManager.TYPE_WIFI) {         return true;        } else if (netWorkInfo.getType() == ConnectivityManager.TYPE_MOBILE) {         return true;        }       }      }     }    }      return false;     }