通过剪贴板添加时无法访问 Microsoft Teams Activity 中的图像

Question

I am working on a bot which receives messages from Teams via the Botframework and sends them to another application. I'm using .NET Core.

So far everything works fine, I can move texts, emojis, files etc. But I have a problem with images in the clipboard.

When sending a normal file, I can access it with the Attachment.Content["downloadUrl"] of the activity which I receive from the Botframework.

But when I insert images from the clipboard, it is stored in another way, with the Activity I get two attachments with different urls (one for layout and one for the image resource, I suppose?), like the image below, but when trying to GET the image, I receive an 401 Unauthorized.

Is there a way to access these images pasted from the clipboard, or are these probably only visible/accessible from inside Microsoft Teams?

Help me, Obi-Wan Kenobi. You're my only hope.

Thank you for your time!

EDIT: Thank you for your warm welcome!

I am using the OnMessageActivityAsync overload from here:
https://docs.microsoft.com/en-us/microsoftteams/platform/bots/bot-basics?tabs=csharp#bot-logic

    public class BotActivityHandler : Microsoft.Bot.Builder.Teams.TeamsActivityHandler
    {
        [...]

        protected override async Task OnMessageActivityAsync(ITurnContext<IMessageActivity> turnContext, CancellationToken cancellationToken)
        {
            // it's either this url or the one parsed from the html, but both receive a 401 with a GET request like below or with Postman
            var imageUrl = turnContext.Activity.Attachments.Where(x => !x.ContentUrl.IsNullOrEmpty()).ToList().First().ContentUrl;

            var response = await myHttpClient.GetAsync(imageUrl);
            var img = await response.Content.ReadAsStreamAsync();
        }
[...]

The turnContext includes an Activity with two Attachments: One has Content like

<div><div>\n<div><span><img
src=\"https://eu-api.asm.skype.com/v1/objects/[...]/views/imgo\"
 width=\"247\" id=\"[...]\" itemscope=\"\" itemtype=\"http://schema.skype.com/AMSImage\"\"></span>\n\n</div>\n\n\n</div>\n</div>

And the other one a ContentUrl like

"https://smba.trafficmanager.net/emea/v3/attachments/[...]/views/original"

Answer 1

Answered in https://github.com/MicrosoftDocs/msteams-docs/issues/1561

One can use the MicrosoftAppCredentials to receive a JWT Token to access the images.

var token = await new MicrosoftAppCredentials("appId", "password").GetTokenAsync();
httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token);