使用不在Skype频道中工作的Bot框架上传文本文件作为附件

Question

在Skype频道中尝试时，我无法使用Bot框架（Bot.Builder v3.11.0）将文本文件上传为附件。它虽然在Bot框架模拟器中工作。以下是上传文件并返回附件中上传文件URL的活动的代码。使用Skype频道时会抛出异常。或者，有没有其他方法可以在Skype频道中上传/附加文本文件，然后用户可以从客户端下载该文件？

public static async Task<Activity> GetTextAttachmentAsync(Activity message)
{
    var reply = message.CreateReply("Here is a text attachment");
    var serviceUrl = reply.ServiceUrl;
    var conversationId = reply.Conversation.Id;

    byte[] fileData = null;
    using (var wc = new System.Net.WebClient())
        fileData = wc.DownloadData("https://textfiles.com/100/adventur.txt");

    using (var connector = new ConnectorClient(new Uri(serviceUrl)))
    {
        var attachments = new Attachments(connector);
        var token = await (connector.Credentials as MicrosoftAppCredentials).GetTokenAsync();
        connector.HttpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token);
        var response = await attachments.Client.Conversations.UploadAttachmentAsync(
            conversationId,
            new AttachmentData
            {
                Name = "transcript.html",
                OriginalBase64 = fileData,
                Type = "text/html"
            });

        reply.Attachments = new List<Attachment>
        {
            new Attachment
            {
                Name = "transcript.html",
                ContentType = "text/html",
                ContentUrl = attachments.GetAttachmentUri(response.Id)
            }
        };

        return reply;
    }
}

上述UploadAttachmentAsync()函数抛出异常：

Microsoft.Rest.HttpOperationException: Not Found
   at Microsoft.Bot.Connector.ErrorHandling.<HandleErrorAsync>d__2`1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.Bot.Connector.ConversationsExtensions.<UploadAttachmentAsync>d__15.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Support.Services.Bot.Core.Utilities.AdaptiveCardsHelper.<GetTextAttachmentAsync>d__4.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Support.Services.Bot.Core.Dialogs.BotDialog.<HandleMessageAsync>d__3.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Support.Services.Bot.Core.Dialogs.DialogBase`1.<MessageReceivedAsync>d__8.MoveNext()

Answer 1

在Visual Studio中启用公共语言运行时错误的情况下运行代码时。我收到以下错误：

网站地址https://textfiles.com/100/adventur.txt似乎没有受信任的证书，这使得.NET不满意。当我去调查时，我发现这个Stack Overflow answer建议使用下面的代码来克服这个问题，但强烈建议不要在生产中使用它。

ServicePointManager.ServerCertificateValidationCallback += (o, c, ch, er) => true;

在我运行您的代码之前，这将是我的原始建议：许多频道（包括Skype），限制您在使用base64和/或本地文件时能够从机器人发送的文件类型。例如，我知道您无法在Skype中将PDF文件作为Base64发送。如果内存正常，您只能使用Skype中的base64方法发送图像和视频文件（也可能是音频）。因此，即使你解决了这个错误，你也可能会遇到这种情况。解决方法是使用托管文件。我并不完全确定您要对机器人做什么，所以我不确定这是否适合您，但这是一个选项。

因此，如果您在解决证书问题后发现此代码无效，请尝试发送图像文件，看看是否有效，如果确实如此，但HTML文件仍然失败，您就会知道这就是原因。