c# - Bot Framework 如何在确认对话框中添加标题

Question

我正在按照本教程构建一个聊天机器人。

我的代码在Microsoft Bot Framework Emulator上运行良好，但在Facebook Messenger中进行测试时出现问题：

Is this your selection?
* Sandwich: Black Forest Ham
* Length: Six Inch
....
> no
What do you want to change? //Facebook Messenger stop and not display this line
 1. Sandwich(Black Forest Ham)
 2. Length(Six Inch)
> 2

这里是消息 Bot Framework：

{"error":{"message":"(#100) Param [elements][0][title] must be a non-empty UTF-8 encoded string","type":"OAuthException","code":100,"fbtrace_id":"HfCTxxxx"}}

我用模拟器调试，发现我的机器人返回内容为空Title。

 "attachments": [
{
  "contentType": "application/vnd.microsoft.card.hero",
  "content": {
    "title": "",
    "text": "What do you want to change? ",
    "buttons": [

用户输入时如何覆盖此卡no？

谢谢