BotFramework 和 LUIS 出现 JSON 序列化器错误

StackOverflow 社区！

我有一个聊天机器人，并集成了 LUIS.ai 以使其更加智能。其中一个对话即将与主管（老师）预约 一切都运行良好，代码完全相同。几个小时前，我遇到了一些奇怪的错误。

 Exception: Type 'Newtonsoft.Json.Linq.JArray' in Assembly 'Newtonsoft.Json, Version=10.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed' is not marked as serializable.

如何重现错误？

如果用户输入中缺少两个实体（教师和日期），则工作正常，机器人会构建表单，询问缺少的输入并显示建议的会议时间。

如果其中一个实体在输入中丢失，它将构建一个表格并询问丢失的日期或教师实体并显示建议的会议时间。

BUT

如果用户的输入同时包含实体：教师和日期，那么我会收到错误。

这是我的 WebApiConfig 类：

public static class WebApiConfig
    {
        public static void Register(HttpConfiguration config)
        {
            // Json settings
            config.Formatters.JsonFormatter.SerializerSettings.NullValueHandling = NullValueHandling.Ignore;
            config.Formatters.JsonFormatter.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
            config.Formatters.JsonFormatter.SerializerSettings.Formatting = Formatting.Indented;
            JsonConvert.DefaultSettings = () => new JsonSerializerSettings()
            {
                ContractResolver = new CamelCasePropertyNamesContractResolver(),
                Formatting = Newtonsoft.Json.Formatting.Indented,
                NullValueHandling = NullValueHandling.Ignore,
            };

            // Web API configuration and services

            // Web API routes
            config.MapHttpAttributeRoutes();

            config.Routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );
        }
    }

仅当我尝试从用户话语中获取实体（一种builtin.dateTimeV2）时，我才会遇到此错误。

这个异步方法被称为：

    //From the LUIS.AI language model the entities
    private const string EntityMeetingDate = "MeetingDate";
    private const string EntityTeacher = "Teacher";

    [LuisIntent("BookSupervision")]
public async Task BookAppointment(IDialogContext context, IAwaitable<IMessageActivity> activity, LuisResult result)
{
    var message = await activity;
    await context.PostAsync($"I am analysing your message: '{message.Text}'...");

    var meetingsQuery = new MeetingsQuery();

    EntityRecommendation teacherEntityRecommendation;
    EntityRecommendation dateEntityRecommendation;

    if (result.TryFindEntity(EntityTeacher, out teacherEntityRecommendation))
    {
        teacherEntityRecommendation.Type = "Name";
    }
    if (result.TryFindEntity(EntityMeetingDate, out dateEntityRecommendation))
    {
        dateEntityRecommendation.Type = "Date";
    }

    var meetingsFormDialog = new FormDialog<MeetingsQuery>(meetingsQuery, this.BuildMeetingsForm, FormOptions.PromptInStart, result.Entities);
    context.Call(meetingsFormDialog, this.ResumeAfterMeetingsFormDialog);

}

构建表单的其他方法：

 private IForm<MeetingsQuery> BuildMeetingsForm()
{
    OnCompletionAsyncDelegate<MeetingsQuery> processMeetingsSearch = async (context, state) =>
    {
        var message = "Searching for supervision slots";
        if (!string.IsNullOrEmpty(state.Date))
        {
            message += $" at {state.Date}...";
        }
        else if (!string.IsNullOrEmpty(state.Name))
        {
            message += $" with professor {state.Name}...";
        }
        await context.PostAsync(message);
    };

    return new FormBuilder<MeetingsQuery>()
        .Field(nameof(MeetingsQuery.Date), (state) => string.IsNullOrEmpty(state.Date))
        .Field(nameof(MeetingsQuery.Name), (state) => string.IsNullOrEmpty(state.Name))
        .OnCompletion(processMeetingsSearch)
        .Build();
}

private async Task ResumeAfterMeetingsFormDialog(IDialogContext context, IAwaitable<MeetingsQuery> result)
{
try
{
    var searchQuery = await result;

    var meetings = await this.GetMeetingsAsync(searchQuery);

    await context.PostAsync($"I found {meetings.Count()} available slots:");

    var resultMessage = context.MakeMessage();
    resultMessage.AttachmentLayout = AttachmentLayoutTypes.Carousel;
    resultMessage.Attachments = new List<Attachment>();

    foreach (var meeting in meetings)
    {
        HeroCard heroCard = new HeroCard()
        {
            Title = meeting.Teacher,
            Subtitle = meeting.Location,
            Text = meeting.DateTime,
            Images = new List<CardImage>()
            {
                new CardImage() {Url = meeting.Image}
            },
            Buttons = new List<CardAction>()
            {
                new CardAction()
                {
                    Title = "Book Appointment",
                    Type = ActionTypes.OpenUrl,
                    Value = $"https://www.bing.com/search?q=easj+roskilde+" + HttpUtility.UrlEncode(meeting.Location)
                }
            }
        };

        resultMessage.Attachments.Add(heroCard.ToAttachment());
    }

    await context.PostAsync(resultMessage);
}
catch (FormCanceledException ex)
{
    string reply;

    if (ex.InnerException == null)
    {
        reply = "You have canceled the operation.";
    }
    else
    {
        reply = $"Oops! Something went wrong :( Technical Details: {ex.InnerException.Message}";
    }

    await context.PostAsync(reply);
}
finally
{
    context.Wait(DeconstructionOfDialog);
}
}


private async Task<IEnumerable<Meeting>> GetMeetingsAsync(MeetingsQuery searchQuery)
{
    var meetings = new List<Meeting>();

    //some random result manually for demo purposes
    for (int i = 1; i <= 5; i++)
    {
        var random = new Random(i);
        Meeting meeting = new Meeting()
        {
            DateTime = $" Available time: {searchQuery.Date} At building {i}",
            Teacher = $" Professor {searchQuery.Name}",
            Location = $" Elisagårdsvej 3, Room {random.Next(1, 300)}",
            Image = $"https://placeholdit.imgix.net/~text?txtsize=35&txt=Supervision+{i}&w=500&h=260"
        };

        meetings.Add(meeting);
    }

    return meetings;
}

最奇怪的是，这段代码起作用了，我对 GitHub 上的社区表示敬意和尊重，因为我认为这是一个很棒的平台，拥有大量文档和示例。

这是已知问题（也报告了here and here).

长话短说，由于 BotBuilder 尚不支持builtin.datetimeV2.* 实体，Resolution字典的EntityRecommendation最终得到一个值为 type 的条目JArray。当您将这些实体传递给FormDialog。由于实体是对话框中的私有字段，并且当然与任何其他对话框一样，正在被序列化，因此会抛出异常，因为JArray班级来自Newtonsoft未标记为可序列化。

添加对 datetimeV2 实体的支持的请求是here.

我现在能想到的解决方法是手动提取 DateTime 实体的值并将其分配给您Date你的领域MeetingsQuery您传递给的实例FormDialog并从中删除 DateTime 实体result.Entities您要传递给的集合FormDialog.

Update

正如您所见，这个问题已经在 SDK 中修复了这个请求请求.