如何從 HttpResponseMessage 讀取應用程序/pdf 內容類型並將其轉換為 stream

Question

我有一個 Web API 連接到另一個端點。 來自第二個 Web API 的 GET 方法返回應用程序/pdf 內容類型。 在這里，我成功獲取了數據。 如何將 response.Content 轉換為文件/內存 stream 並返回值？

 public async Task<T> functionname<T>(ApplicationApiRoutes.APIRoutes route, string token = "", int TimeoutMinutes = 5, CancellationToken cancellationToken = default, params string[] routeparams)
    {
        T Response = default;
        try
        {
            ApplicationApiRoutes._RouteHashTable.TryGetValue(route, out string FormattedRoute);

            FormattedRoute = String.Format(FormattedRoute, routeparams);

            using (var request = new HttpRequestMessage(HttpMethod.Get, $"{FormattedRoute}"))
            {
                if (!String.IsNullOrWhiteSpace(token))
                {
                    request.Headers.Add("Cookie", $"access_token="+ token);
                }
                
               

                using (var response = await _httpclient
                    .SendAsync(request, HttpCompletionOption.ResponseHeadersRead, cancellationToken))
                {

                    
                   
                    response.EnsureSuccessStatusCode();

                    var result = await response.Content.ReadAsStringAsync();

                    Response = JsonConvert.DeserializeObject<T>(result, _jsonsettings);
                }
            }
        }
        catch (Exception ex)
        {
           
        }

        return Response;
    }

Answer 1

假設您想在檢索文件后下載文件，請在您的 controller 操作方法中嘗試以下操作：

var fileStream = new MemoryStream();

using (var file = await _httpClient.GetStreamAsync(request).ConfigureAwait(false))
{
      await file.CopyToAsync(fileStream);
}

fileStream.Position = 0;  
return File(fileStream , "application/pdf", "filename.pdf");