问在angular应用和v4机器人框架机器人之间发送聊天历史记录(C# + .Net核心Web应用，Angular 8前端)

EN

    window.WebChat.renderWebChat(
      {
          directLine,
          userID: id + '',
          username: 'user'
      },
      this.botWindowElement.nativeElement
  );

    directLine
      .postActivity({
          from: { id: id + '', name: 'webchat_user' },
          name: 'requestWelcomeDialog',
          type: 'event',
          value: 'token'
      })
      .subscribe(
          id => console.log(`Posted activity, assigned ID ${id}`),
          error => console.log(`Error posting activity ${error}`)
      );

        protected override async Task OnTeamsMembersAddedAsync(IList<TeamsChannelAccount> membersAdded, TeamInfo teamInfo, ITurnContext<IConversationUpdateActivity> turnContext, CancellationToken cancellationToken)
        {
            foreach (TeamsChannelAccount member in membersAdded)
            {
                if (member.Id != turnContext.Activity.Recipient.Id)
                {
                    await turnContext.SendActivityAsync(MessageFactory.Text($"Welcome {member.Name}!"), cancellationToken);
                }
            }
        }