使用VS2019 .net coer3.1 开发Teams Bot，获取Teams用户信息和发送主动消息

首先创建一个自定义的Bot，可以查看ActivityHandler里面的方法，根据自己的需要进行重写

using Microsoft.Bot.Builder;
using Microsoft.Bot.Builder.Teams;
using Microsoft.Bot.Schema;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;

namespace EmptyBot1
{
    public class TestBot: ActivityHandler
    {
        protected override async Task OnMembersAddedAsync(IList membersAdded, ITurnContext turnContext, CancellationToken cancellationToken)
        {
            foreach (var member in membersAdded)
            {
                if (member.Id != turnContext.Activity.Recipient.Id)
                {
                    await turnContext.SendActivityAsync(MessageFactory.Text($"Hello world TestBot!"), cancellationToken);
                }
            }
        }
        protected override async Task OnMessageActivityAsync(ITurnContext turnContext, CancellationToken cancellationToken)
        {
            await turnContext.SendActivityAsync(MessageFactory.Text($"You sead {turnContext.Activity.Text}"),cancellationToken);     
        }

        protected override async Task OnConversationUpdateActivityAsync(ITurnContext turnContext, CancellationToken cancellationToken)
        {
            var member = await TeamsInfo.GetMemberAsync(turnContext, turnContext.Activity.From.Id, cancellationToken);
            var message = turnContext.Activity;
            ConversationStarter.toId = message.From.Id;
            ConversationStarter.toName = message.From.Name;
            ConversationStarter.fromId = message.Recipient.Id;
            ConversationStarter.fromName = message.Recipient.Name;
            ConversationStarter.serviceUrl = message.ServiceUrl;
            ConversationStarter.channelId = message.ChannelId;
            ConversationStarter.conversationId = message.Conversation.Id;
            await turnContext.SendActivityAsync(MessageFactory.Text($"Hello world!{member.Name}"), cancellationToken);
        }
    }
}

第二步，修改Startup.cs中，中文注释的代码部分

// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License.
//
// Generated with Bot Builder V4 SDK Template for Visual Studio EmptyBot v4.9.2

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Bot.Builder;
using Microsoft.Bot.Builder.Integration.AspNet.Core;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;

namespace EmptyBot1
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllers().AddNewtonsoftJson();

            // Create the Bot Framework Adapter with error handling enabled.
            services.AddSingleton();

            // Create the bot as a transient. In this case the ASP Controller is expecting an IBot.
            //将此处原本指向默认Bot服务的对象，修改成指向自定义的TestBot
            services.AddTransient();
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            app.UseDefaultFiles()
                .UseStaticFiles()
                .UseWebSockets()
                .UseRouting()
                .UseAuthorization()
                .UseEndpoints(endpoints =>
                {
                    endpoints.MapControllers();
                });

            // app.UseHttpsRedirection();
        }
    }
}

追后只需要在需要的地方调用发送消息的代码，就能主动给Teams用户发送消息了

//发送消息
await ConversationStarter.Resume(msg)