ボットからメッセージを送る (プロアクティブなメッセージ)

private async Task<DialogTurnResult> SaveConversationReference(DialogContext dc, object options)
{
    var member = await TeamsInfo.GetMemberAsync(dc.Context, dc.Context.Activity.From.Id, default);
    if (member != null)
    {
        var email = member.Email;
        var value = dc.Context.Activity.GetConversationReference();

        var storage = dc.Context.TurnState.Get<IStorage>();
        IDictionary<string, object> changes = new Dictionary<string, object>
        {
            { $"ConversationReference_{email}", value }
        };

        await storage.WriteAsync(changes);
    }

    return await dc.EndDialogAsync(options);
}

using DemoBot1.Models;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Bot.Builder;
using Microsoft.Bot.Builder.Integration.AspNet.Core;
using Microsoft.Bot.Schema;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Primitives;
using System;
using System.Net.Mime;
using System.Threading;
using System.Threading.Tasks;

namespace DemoBot1.Controllers
{
    [Route("api/proactive")]
    [ApiController]
    public class ProactiveController : ControllerBase
    {
        private readonly IBotFrameworkHttpAdapter _adapter;
        private readonly string _appId;
        private readonly ILogger _logger;
        private readonly IStorage _storage;

        public ProactiveController(
            IBotFrameworkHttpAdapter adapter,
            IConfiguration config,
            ILogger<ProactiveController> logger, 
            IStorage storage)
        {
            _adapter = adapter;
            _appId = config["MicrosoftAppId"];
            _logger = logger;
            _storage = storage;
        }

        [HttpPost]
        [Consumes(MediaTypeNames.Application.Json)]
        [ProducesResponseType(StatusCodes.Status400BadRequest)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        public async Task<IActionResult> PostAsync(ProactiveParam param)
        {
            if (StringValues.IsNullOrEmpty(param.Email))
            {
                _logger.LogWarning("クエリパラメータの email が指定されていません。");
                return BadRequest();
            }

            string key = $"ConversationReference_{param.Email}";
            var values = await _storage.ReadAsync(new[] { key });
            ConversationReference value = null;
            if (values.ContainsKey(key))
            {
                value = (ConversationReference) values[key];
            }

            if (value == null)
            {
                _logger.LogWarning($"{param.Email} の ConversationReference は保存されていません。");
                return NotFound();
            }

            await ((BotAdapter)_adapter).ContinueConversationAsync(_appId, value, BotCallback, default);

            return Ok();
        }

        private Task BotCallback(ITurnContext turnContext, CancellationToken cancellationToken)
        {
            // 何か処理をする
            throw new NotImplementedException();
        }
    }
}

$url = "http://localhost:3978/api/proactive"
$body = @{
    "Email" = "xxx@example.com"
}
$bodyStr = ConvertTo-Json $body
$bodyBytes = [Text.Encoding]::UTF8.GetBytes($bodyStr)

Invoke-WebRequest $url -Body $bodyBytes -Method "Post" -ContentType "application/json"