c# - 使用 JSON JavaScriptSerializer 进行序列化或反序列化时出错。

Question

我在尝试创建 json 时不断收到此错误。这是完整的错误

Error during serialization or deserialization using the JSON 
JavaScriptSerializer. The length of the string exceeds
the value set on the maxJsonLength property.

我的代码如下

public ActionResult ChangeRequests_Read([DataSourceRequest] DataSourceRequest request)
    {
        var data = GetRequests();
        var serializer = new JavaScriptSerializer();
        var result = new ContentResult();
        serializer.MaxJsonLength = Int32.MaxValue; // Whatever max length you want here
        result.Content = serializer.Serialize(data.ToDataSourceResult(request));
        result.ContentType = "application/json";
        return result;

        //return Json(GetRequests().ToDataSourceResult(request), JsonRequestBehavior.AllowGet);
    }

从这里开始

public static IEnumerable<ChangeRequestsVM> GetRequests()
    {
        var model = CompanyContextFactory.GetContextPerRequest();
        var chrwVM =  model.ChangeRequestsHDRs.Where(ch=> ch.CompanyID == GlobalVariables.CompanyID).Select(ch=> new ChangeRequestsVM
        {
            RequestID = ch.RequestID, 
            CompanyID = ch.CompanyID,
            ClientID = ch.ClientID,
            EmployeeID = (string.IsNullOrEmpty(ch.EmployeeID)) ? "NA" : ch.EmployeeID,
            AssignmentType = ch.AssignmentType,
            Key1 = ch.Key1,
            Key2 = ch.Key2,
            LogonID = ch.LogonID,
            ProcessDate = ch.ProcessDate,
            ProcessTime = ch.ProcessTime,
            ProcessUserID = ch.ProcessUserID,
            RequestDate = ch.RequestDate,
            RequestExport = ch.RequestExport,
            RequestNote = ch.RequestNote,
            RequestOrigin = Convert.ToChar(ch.RequestOrigin),
            RequestProcess = ch.RequestProcess,
            RequestStatus = ch.RequestStatus,
            RequestTime = ch.RequestTime,
            RequestType = Convert.ToChar(ch.RequestType),
            ResponseNote = ch.ResponseNote,
            TableName = ch.TableName,
            TransferDate = ch.TransferDate,
            TransferTime = ch.TransferTime,
            TransferUserID = ch.TransferUserID,
            dispOrigin = (Convert.ToChar(ch.RequestOrigin) == ChangeRequestOrigin.System) ? "System" : (Convert.ToChar(ch.RequestOrigin) == ChangeRequestOrigin.Client) ? "Client" : "Employee",
            dispRequestType = (Convert.ToChar(ch.RequestType) == ChangeRequestType.Insert) ? "Insert" : (Convert.ToChar(ch.RequestType) == ChangeRequestType.Alter) ? "Change" : "Delete",
            dispStatus = FieldTranslation.GetEnumDescription(typeof(enChangeRequestStatus), ch.RequestStatus ?? 0)
        }).OrderByDescending(ch=> ch.RequestID);
        return chrwVM;
    }

为什么我的 json 超长了？我做到了，所以该方法只从数据库中提取一项，但仍然出现错误。

Answer 1

您需要增加 MaxJsonLength 属性的大小:

https://msdn.microsoft.com/en-us/library/system.web.script.serialization.javascriptserializer.maxjsonlength.aspx

这是在配置文件中完成的。有关详细信息，请参阅上面的链接。

更新:

由于您使用的是 MVC，因此您可以使用以下应用设置:

<appSettings>
    <add key="aspnet:MaxJsonDeserializerMembers" value="123456789" />
...
</appSettings>

但是，请注意这是一个潜在的安全风险。在这里阅读更多:

https://msdn.microsoft.com/en-us/library/hh975440(v=vs.120).aspx