Angular结合VSTO同步Outlook日历遇参数及HTTP请求错误

我正在开发一款面向内部开发者的Angular休假管理系统，支持员工申请休假/病假、管理员审批等功能。现在配置通过VSTO向Outlook同步日历数据的功能时遇到问题：点击生成Outlook日历按钮时，请求的year参数为undefined，且HTTP请求返回未知错误。

相关代码 #

outlook-calendar.service.ts #

import { Injectable } from '@angular/core';
import { HttpClient, HttpHeaders } from '@angular/common/http';
import { Observable, BehaviorSubject } from 'rxjs';
import { ReturnHandler } from '../modules/vacation/Models/ReturnHandler';
import { OutlookCalendar } from '../modules/vacation/Models/outlookCalendar';

@Injectable({
  providedIn: 'root'
})

export class OutlookCalendarService {
  httpOptions = {
    headers: new HttpHeaders({ 'Content-Type': 'application/json' })
  };
  
  private OutlookUrl = '/api/OutlookCalendar';
  private outlookBH$: BehaviorSubject<number> = new BehaviorSubject<number>(0);
  public outlook$: Observable<number> = this.outlookBH$.asObservable();

  constructor(private http: HttpClient) { }
  
  AddOutlookAppointment(outlookCalendar: OutlookCalendar) : Observable<ReturnHandler> {
    const url = `${this.OutlookUrl}/CreateAppointment`;
    return this.http.post<ReturnHandler>(url, outlookCalendar, this.httpOptions);
  }

  DeleteOutlookAppointment(outlookCalendar: OutlookCalendar) : Observable<ReturnHandler> {
    const url = `${this.OutlookUrl}/DeleteAppointment`;
    return this.http.post<ReturnHandler>(url, outlookCalendar, this.httpOptions);
  }

  OutlookYearCalendarGenerator(year: number) : Observable<ReturnHandler>{
    const url = `http://localhost:50304/vac/api/OutlookCalendar/CreateNewOutlookCalendar?year=${year}`;
    //const url = `${this.OutlookUrl}/CreateNewOutlookCalendar?year=${year}`;
    console.log(year);
    return this.http.get<ReturnHandler>(url, this.httpOptions);
  }

  // WriteOutlookNationalHolidays(year: string) : Observable<ReturnHandler>{
  //   const url = `${this.url}/WriteOutlookNationalHolidays?year=${year}`;
  //   return this.http.get<ReturnHandler>(url,this.httpOptions);
  // }
}

ThisAddIn.cs #

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;
using Outlook = Microsoft.Office.Interop.Outlook;
using Office = Microsoft.Office.Core;
using System.Windows.Forms;
using System.IO;

namespace OutlookCalendar
{
    public partial class ThisAddIn
    {
        private OutlookCalendarCs outlookCalendar;

        protected override object RequestComAddInAutomationService()
        {
            if(outlookCalendar == null)
                    outlookCalendar = new OutlookCalendarCs();

            return outlookCalendar;
        }

        private void ThisAddIn_Startup(object sender, EventArgs e)
        {
            Outlook.NameSpace session = Globals.ThisAddIn.Application.Session;
            Outlook.Accounts accounts = session.Accounts;
            List<Outlook.MAPIFolder> calendars = new List<Outlook.MAPIFolder>();

            foreach (Outlook.Account account in accounts)
            {
                Outlook.Recipient recipient = session.CreateRecipient(account.DisplayName);
                Outlook.MAPIFolder calendar = session.GetSharedDefaultFolder(recipient, Outlook.OlDefaultFolders.olFolderCalendar);
                if (calendar != null)
                {
                    calendars.Add(calendar);
                }
            }

            File.WriteAllLines("dd.txt", (IEnumerable<string>)calendars);

            Console.WriteLine(calendars);

            using (TextWriter tw = new StreamWriter("C:\\AxessCroTools\\IIS\\dd.txt"))
            {
                foreach (Outlook.MAPIFolder calendar in calendars)
                {
                    tw.WriteLine(calendar);
                }
            }
        }

        private void ThisAddIn_Shutdown(object sender, System.EventArgs e)
        {
            // Note: Outlook no longer raises this event. If you have code that 
            //    must run when Outlook shuts down, see https://go.microsoft.com/fwlink/?LinkId=506785
        }
        #region VSTO generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InternalStartup()
        {
            this.Startup += new System.EventHandler(ThisAddIn_Startup);
            this.Shutdown += new System.EventHandler(ThisAddIn_Shutdown);
        }
        
        #endregion
    }
}

错误信息 #

Http failure response for http://localhost:50304/vac/api/OutlookCalendar/CreateNewOutlookCalendar?year=undefined: 0 Unknown Error

排查方向 #

1. 参数传递问题：

   • 检查调用OutlookYearCalendarGenerator方法的组件代码，确认传入的year值是否正确初始化或获取（比如从日期选择器、表单输入等来源），避免出现未定义的情况。
   • 查看浏览器控制台输出的year值（代码中已添加console.log(year)），确认调用方法时参数是否确实未传递。

2. API请求配置问题：

   • 当前硬编码了API地址，建议改用代码中注释的相对路径${this.OutlookUrl}/CreateNewOutlookCalendar?year=${year}，避免跨域或环境不一致问题。
   • 确认后端API服务是否正常运行，CreateNewOutlookCalendar接口能否正常接收year参数并返回有效响应。

3. VSTO侧关联问题：

   • 当前VSTO代码仅在启动时获取日历列表并写入文件，未实现与Angular前端的交互逻辑。需确认后端API是否正确调用了VSTO的自动化服务（OutlookCalendarCs类）来生成日历，同时确保VSTO插件已正确加载并注册。

内容的提问来源于stack exchange，提问作者Hrvoje