Newtonsoft.Json.JsonReaderException: 解析值时遇到意外字符 - ASP.NET

Question

如何在 ASP.NET Core Web API 中使用 Telegram.Bot 包开发 Telegram 机器人时正确反序列化 POST 方法“更新”？ 我使用 DeserializeObject(string) 方法这样做，但它一直返回错误：Newtonsoft.Json.JsonReaderException: Unexpected character encountered while parsing value

代码：

using Microsoft.AspNetCore.Mvc;
using Telegram.Bot;
using Telegram.Bot.Types;
using Telegram.Bot.Types.Enums;
using Telegram.Bot.Types.ReplyMarkups;
using Newtonsoft.Json;

namespace OfficeBooking.TelegramApi.Controllers
{
    [ApiController]
    [Route(template: "api/message")]
    public class TelegramBotController : ControllerBase
    {
        private readonly TelegramBotClient _telegramBotClient;

        public TelegramBotController(TelegramBot telegramBot)
        {
            _telegramBotClient = telegramBot.GetBot().Result;
        }

        [HttpPost]
        public async Task <IActionResult> Update([FromBody]object update)
        {
            var upd = JsonConvert.DeserializeObject<Update>(update.ToString());
            var chat = upd.Message?.Chat;

            if (chat == null)
            {
                return Ok();
            }

            await _telegramBotClient.SendTextMessageAsync(
                    chatId: chat.Id,
                    text: "Testing sendMessage method",
                    parseMode: ParseMode.MarkdownV2,
                    disableNotification: false,
                    replyMarkup: new InlineKeyboardMarkup(
                        InlineKeyboardButton.WithUrl(
                            "Check sendMessage method",
                            "https://core.telegram.org/bots/api#sendmessage")));

            return Ok();
        }
    }
}

Answer 1

我认为您应该尝试依靠 ASP.NET Core 来解析您的 json 输入。您可以简单地指定类型 Update 而不是 object ，它将为您完成剩下的工作。您只需要使用类型为 Update:

的现成对象

        [HttpPost]
        public async Task <IActionResult> Update([FromBody]Update update)
        {
            var chat = update.Message?.Chat;

            if (chat == null)
            {
                return Ok();
            }

            await _telegramBotClient.SendTextMessageAsync(
                    chatId: chat.Id,
                    text: "Testing sendMessage method",
                    parseMode: ParseMode.MarkdownV2,
                    disableNotification: false,
                    replyMarkup: new InlineKeyboardMarkup(
                        InlineKeyboardButton.WithUrl(
                            "Check sendMessage method",
                            "https://core.telegram.org/bots/api#sendmessage")));

            return Ok();
        }

如果您希望框架使用 NewtonsoftJson 而不是默认的 Json 实用程序（在您的情况下这不是必需的），请遵循此说明 https://dotnetcoretutorials.com/2019/12/19/using-newtonsoft-json-in-net-core-3-projects/