WebClient.DownloadData 在 Bot Framework 中引发异常

Question

我正在上传图像并使用带有 DownloadData 的 WebClient 来获取字节数组，但现在它给我抛出了一个异常：

Exception: State size exceeded configured limit.
[File of type 'text/plain']

我以前从未注意到完全相同的图像的这种行为。可能出了什么问题？

private async Task SendPhoto_ActivityReceivedAsync(IDialogContext context, IAwaitable<object> result)
    {
        Activity activity = await result as Activity;
        Activity activityReply = activity.CreateReply();
        if (0 < activity.Attachments?.Count)
        {
            if (activity.Attachments.FirstOrDefault().ContentType.Equals("image/jpg") ||
                activity.Attachments.FirstOrDefault().ContentType.Equals("image/jpeg") ||
                activity.Attachments.FirstOrDefault().ContentType.Equals("image/png") ||
                activity.Attachments.FirstOrDefault().ContentType.Equals("image/tiff"))
            {
                picImage = activity.Attachments.FirstOrDefault().Name;
                HttpClient httpClient= new HttpClient();
                picImageFile = await httpClient.GetByteArrayAsync(activity.Attachments.FirstOrDefault().ContentUrl);
                await context.PostAsync("Want to send another?");
                context.Wait(SendAnotherImage_ActivityReceivedAsync);
            }
        }
    }

更新：将WebClient更改为HttpClient.GetByteArrayAsync，问题仍然存在。执行 PostAsync 后，该异常立即显示在机器人模拟器中

Answer 1

问题是picImageFile是对话框内部的变量，因此由于对话框已序列化，因此它被保存在状态中。两个选项

1. 下载映像并以该方法进行处理，而不将其保存在内存中
2. 将字节数组保存在外部存储中。