您需要ScriptMethod到您的Web方法，因为你需要发送响应为JSON。

You need to ScriptMethod to your web method because you needs to send the response as json.

[WebMethod]
[ScriptMethod(ResponseFormat = ResponseFormat.Json)]      
public bool SavePins(string saveData)
{
     try
      {
           File.WriteAllText(string.Format("{0}{1}.shane", file_location, "pinsData"),     saveData);
           return true;
      }
     catch (Exception)
     {
        return false;
      }
 }