百度推广api之搜索推广下ReportService接口下获取数据失败，咨询咨询！

接口文档的提示很模糊，找不到是什么原因所致的。
代码为：

 public K DoRequest<T, K>(string methodName, T request) // 其实可以从request得到methodName
        {
            System.Diagnostics.Debug.Assert(!string.IsNullOrEmpty(methodName) && request != null);
            if (methodName == null || request == null)
            {
                return default(K);
            }

            if (this.methodName != methodName)
            {
                this.methodName = methodName;
                this.url = GetEndpoint(this.ServiceType, this.methodName);
            }

            // handle request
            JSONEnvelop<AuthHeader, T> reqEnvelop = new JSONEnvelop<AuthHeader, T>(AuthHeaderValue, request);
            string reqJson = Serialize<JSONEnvelop<AuthHeader, T>>(reqEnvelop);

            //byte[] reqBytes = Compress(reqJson);
            byte[] reqBytes = Encoding.UTF8.GetBytes(reqJson);

            // actual request
            byte[] resBytes = HttpPostService.HttpPost(this.url, this.Timeout, reqBytes, BaiduConfig.ClientId);

            // handle response
            string resJson = Encoding.UTF8.GetString(resBytes);

            JSONEnvelop<ResHeader, K> resEnvelop = DeSerialize<JSONEnvelop<ResHeader, K>>(resJson);
            ResHeaderValue = resEnvelop.header;
            return resEnvelop.body;
        }

返回结果
百度api提示：
901999 Dataitem size is litte than 3 Dataitem size is litte than 3

调用getRealTimeData方法
请求：

返回结果：

调用getCampaign方法
请求：

**返回结果：****

http://www.csdn.net/tag/%E7%99%BE%E5%BA%A6%E6%8E%A8%E5%B9%BF