Question

我正在使用Bot Framework v4 SDK。我正在尝试将通过bot上传到Microsoft Teams的图片下载到一个临时目录中，然后使用该图片。我之所以愿意这样做，是因为我需要拍摄用户附加到聊天中的照片，然后将其放入文档中，然后将文档返回给用户。当我在模拟器上运行它时，此方法有效，但是一旦该机器人进入了Teams，我就会出错。

我通过附件提示提示用户输入照片：

return await stepContext.PromptAsync(
    "imagePrompt",
    new PromptOptions
    {
        Prompt = MessageFactory.Text("Please attach a picture."),
    });

从stepContext.Result中获取附件：

List<Attachment> contextAttachmentResult = (List<Attachment>)stepContext.Result;

确定文件的托管位置

var remoteFileUrl = contextAttachmentResult[0].ContentUrl;

设置系统临时目录的路径

var tempImagePath = Path.Combine(Path.GetTempPath(), contextAttachmentResult[0].Name);

并尝试使用WebClient

下载文件

using (var webClient = new WebClient())
{
    webClient.Headers.Add("User-Agent", "Other");
    webClient.Headers.Add("Authorization", userProfile.Token);
    webClient.DownloadFile(remoteFileUrl, tempImagePath);
}

我尝试将令牌放入从OAuthPrompt获得的令牌中，但仍然收到403。当我尝试下载403时，它就出现了。我认为这是SharePoint问题，是因为如果我打印出remoteFileUrl，我会得到https://company-my.sharepoint.com/personal/my_name/Documents/Microsoft Teams Chat Files/someImage.png

堆栈跟踪的开始是：

System.Net.WebException: The remote server returned an error: (403) FORBIDDEN. at System.Net.HttpWebRequest.GetResponse() at System.Net.WebClient.GetWebResponse(WebRequest request) at System.Net.WebClient.DownloadBits(WebRequest request, Stream writeStream) at System.Net.WebClient.DownloadFile(Uri address, String fileName)

编辑：根据Mick的评论，我尝试以这种方式使用ConnectorClient（并尝试了两种不同的下载方式）：

using (var connectorClient = new ConnectorClient(new Uri(stepContext.Context.Activity.ServiceUrl, MYAPPID, MYAPPPASSWORD)))
{
    var token = await (connectorClient.Credentials as MicrosoftAppCredentials).GetTokenAsync();
    using (var httpClient = new HttpClient())
    {
        httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token);
        httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue(contextAttachmentResult[0].ContentType));
        var byteArray = await httpClient.GetByteArrayAsync(remoteFileUrl);

    }
    using (var webClient = new WebClient())
    {
        webClient.Headers.Add("User-Agent", "Other");
        webClient.Headers.Add("Authorization", token);
        webClient.DownloadFile(remoteFileUrl, siteReviewFile1ImagePath);
    }
}

但是即使我已将连接器设置为使用我的appId和appPwd System.Net.Http.HttpRequestException: Response status code does not indicate success: 401 (Unauthorized). at System.Net.Http.HttpResponseMessage.EnsureSuccessStatusCode() at System.Net.Http.HttpClient.d__30.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at IBIBot.Dialogs.SiteReviewSpace.SiteReviewDialog.<>c__DisplayClass4_0.<<-ctor>b__2>d.MoveNext() in

，我仍然收到401

我仍然对如何获得此下载感到困惑

Answer 1

不使用Attachment.ContentUrl而是使用Attachment.Content.DownloadUrl解决此问题。 downloadurl是预先授权的下载，因此不需要任何载体或授权标头。我的代码如下所示：

var remoteFileUrl = ((JObject)contextAttachmentResult[0].Content)["downloadUrl"].ToString();
using (var webClient = new WebClient())
{
    webClient.DownloadFile(remoteFileUrl, someFileLocationPath);
}

从Sharepoint下载上传到Bot的图片返回403 FORBIDDEN

1 个答案: