如何在剑道网格中加载大量数据

Question

网络方法：

   <WebMethod()>
   Public Shared Function Pcpacking() As IEnumerable(Of Packing)
   Dim db As New STOREEntities
   Return db.PC_PACKING_HISTORIES. _
   Where(Function(q) q.PACK_DATE > "1388/11/07"). _
   Select(Function(q) New Packing _
              With {.Packdate = q.PACK_DATE,
                    .Packserialnumber = q.PACK_SERIAL_NUMBER,
                    .Netweight = q.NET_WEIGHT,
                    .Packusername = q.PACK_USER_NAME}).ToList()
   End Function

脚本：

$(function () {
       $("#grid").kendoGrid({
           height: 200,
           columns: [
                { field: "Packserialnumber", width: "150px" },
               { field: "Netweight", width: "50px" },
               { field: "Packusername", width: "150px" },
               { field: "Packdate", width: "100px" }
           ],
           editable: false,
           dataSource: {
               schema: {
                   data: "d",
                   model: {
                       id: "Packserialnumber",
                       fields: {
                           Packserialnumber: { editable: false, nullable: true },
                           Netweight: { type: "number", validation: { required: true, min: 1} },
                           Packusername: { validation: { required: true} },
                           Packdate: { validation: { required: true} }
                       }
                   }
               },
               batch: false,
               transport: {
                   read: {
                       url: "Default.aspx/Pcpacking",
                       contentType: "application/json; charset=utf-8",
                       type: "POST"
                   }
               }
           }
       });
   });

在这种情况下（PACK_DATE > "1388/11/07" 366 条记录）一切正常。但是当我将日期更改为 1388/11/06 1260 条记录或 1388/11/05 5460 条记录 或 ... 出现以下错误：

{"Message":"使用JSON JavaScriptSerializer进行序列化或反序列化时出错。字符串的长度超过了值 在 maxJsonLength 属性上设置。 ","StackTrace":" 在 System.Web.Script.Serialization.JavaScriptSerializer。 序列化（对象 obj，StringBuilder 输出，SerializationFormat 序列化格式)\r\n 在 System.Web.Script.Serialization.JavaScriptSerializer.Serialize（对象 对象， SerializationFormat 序列化格式)\r\n 在 System.Web.Script.Services.RestHandler.InvokeMethod（HttpContext 语境， WebServiceMethodData 方法数据，IDictionary`2 rawParams)\r\n
在 System.Web.Script.Services.RestHandler.ExecuteWebServiceCall(HttpContext 上下文，WebServiceMethodData 方法数据)", "ExceptionType":"System.InvalidOperationException"}

我认为剑道网格不支持大数据。有什么建议吗？
对不起我的英语不好。

Answer 1

问题实际上是，默认情况下，如果生成的 JSON 字符串大于 100 kB，.NET JSON 序列化程序会抛出异常。显然，发送数千条记录大于限制。你可以change this setting，但我不会推荐它用于你的应用程序。

相反，将网格配置为一次请求小块数据。看来你可以configure Kendo Grid to load more data as you scroll。

$("#grid").kendoGrid({
    dataSource: {
        type: "odata",
        serverPaging: true,
        serverSorting: true,
        pageSize: 100,
        transport: {
            read: {
                url: "Default.aspx/Pcpacking",
                contentType: "application/json; charset=utf-8",
                type: "POST"
            }
        }
    },
    scrollable: {
        virtual: true
    },

    ...
});

您的服务器端脚本必须处理 Kendo 发送的 top（要发送多少条记录）和 skip（从哪里开始）参数。

Answer 2

$(function () {
       $("#grid").kendoGrid({
           height: 200,
           columns: [
                { field: "Packserialnumber", width: "150px" },
               { field: "Netweight", width: "50px" },
               { field: "Packusername", width: "150px" },
               { field: "Packdate", width: "100px" }
           ],
           editable: false,
           dataSource: {
               schema: {
                   data: "d",
                   model: {
                       id: "Packserialnumber",
                       fields: {
                           Packserialnumber: { editable: false, nullable: true },
                           Netweight: { type: "number", validation: { required: true, min: 1} },
                           Packusername: { validation: { required: true} },
                           Packdate: { validation: { required: true} }
                       }
                   }
               },
               batch: false,
               transport: {
                   read: {
                       url: "Default.aspx/Pcpacking",
                       contentType: "application/json; charset=utf-8",
                       dataType: "json"
                   }
               }
           }
       });
   });