Question

我最近在一个相当广泛的REST API上编写了概念证明，以支持我们的遗留数据组件。但是我发现它在处理更大的数据集（40k +项目）时运行得非常慢。

经过一番研究后，我在SO上发现了一个主题，声称使用memorystream，HttpClientHandlers更有效率，更重要的是使用Gzip进行压缩。所以我更新了我当前的.NET版本并开始在VS2017中重写API。

（应该提到我从未使用过这些数据结构）

然后我在示例中跟随，但已撞墙。我在尝试从API中获取一些数据时收到此错误消息（这只是错误的片段）：

“消息”：“发生错误。”，“ExceptionMessage”：“不能将当前JSON对象（例如{\“name \”：\“value \”}）反序列化为类型 'System.Collections.Generic.List`1 [RESTWebApi.Models.TRK_TrackerFeatures]'

这是代码：

public async Task<IHttpActionResult> GetAll()
{
    DataSet ds = dc.FETCHTRK_TrackerFeatures("", conStr, "");
    List<TRK_TrackerFeatures> arr = new List<TRK_TrackerFeatures>();
    foreach (DataTable table in ds.Tables)
    {
        foreach (DataRow row in table.Rows)
        {
            int? id = row["ID"] as int?;
            String trackercode = row["TrackerCode"] as String;
            Boolean? applicabletoproject = row["ApplicableToProject"] as Boolean?;
            int? trk_feature_lkid = row["TRK_Feature_LKID"] as int?;
            int? trk_trackerstatus_lkid = row["TRK_TrackerStatus_LKID"] as int?;
            int? trk_trackerstatus_lkid2 = row["TRK_TrackerStatus_LKID2"] as int?;
            Boolean? readyforwork = row["ReadyForWork"] as Boolean?;
            String action = row["Action"] as String;
            String responsibleperson = row["ResponsiblePerson"] as String;
            int? tminus = row["TMinus"] as int?;
            DateTime? datetobeactioned = row["DateToBeActioned"] as DateTime?;
            int? trk_startdateid = row["TRK_StartDateID"] as int?;
            String accountableperson = row["AccountablePerson"] as String;
            String comments = row["Comments"] as String;
            DateTime? datestamp = row["DateStamp"] as DateTime?;
            arr.Add(new TRK_TrackerFeatures
            {
                ID = id,
                TrackerCode = trackercode,
                ApplicableToProject = applicabletoproject,
                TRK_Feature_LKID = trk_feature_lkid,
                TRK_TrackerStatus_LKID = trk_trackerstatus_lkid,
                TRK_TrackerStatus_LKID2 = trk_trackerstatus_lkid2,
                ReadyForWork = readyforwork,
                Action = action,
                ResponsiblePerson = responsibleperson,
                TMinus = tminus,
                DateToBeActioned = datetobeactioned,
                TRK_StartDateID = trk_startdateid,
                AccountablePerson = accountableperson,
                Comments = comments,
                DateStamp = datestamp
            });
        }
    }
    using (HttpClientHandler handler = new HttpClientHandler())
    {
        handler.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;
        using (HttpClient client = new HttpClient(handler, false))
        {
            string json = JsonConvert.SerializeObject(arr);
            byte[] jsonBytes = Encoding.UTF8.GetBytes(json);
            MemoryStream ms = new MemoryStream();
            using (GZipStream gzip = new GZipStream(ms, CompressionMode.Compress, true))
            {
                gzip.Write(jsonBytes, 0, jsonBytes.Length);
            }
            ms.Position = 0;
            StreamContent content = new StreamContent(ms);
            content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
            content.Headers.ContentEncoding.Add("gzip");
            HttpResponseMessage response = await client.PostAsync("http://localhost:61090/api/TRK_TrackerFeatures/GetAll", content);
            List<TRK_TrackerFeatures> results = await response.Content.ReadAsAsync<List<TRK_TrackerFeatures>>(); <== error here
            Debug.WriteLine(String.Join(", ", results)); // 
        }
    }
    return Ok();
}

无法将当前JSON对象反序列化为GenericList

0 个答案: