/// <summary> /// 询问服务器,文件是否存在 /// </summary> /// <param name="fileId">要询问的文件信息</param> /// <param name="success">成功回调函数</param> /// <param name="failure">失败回调函数</param> /// <returns>文件是否已经存在</returns> public static void IsFileExistInServer(string fileId, Success <bool> success, Failure failure = null) { var restTemplate = new RestTemplate(); restTemplate.MessageConverters.Add(new NJsonHttpMessageConverter()); restTemplate.HeadForHeadersAsync(Resources.fileInfoUrl + "/" + fileId, resp => { if (resp.Error != null) { failure?.Invoke(resp.Error.Message); } else { var singleValue = resp.Response.GetSingleValue("isExist"); success?.Invoke(!string.IsNullOrWhiteSpace(singleValue) && singleValue.ToUpper().Equals("TRUE")); } }); }