// 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;
 }