检查uri是否有效，而不会使用HttpClient下载它

Question

如何验证下载uri是否有效而不会导致客户端下载内容？

Answer 1

1. 创建客户端
2. 使用client.GetAsync（uri，HttpComplettionOption）api
3. 使用ResponseHeadersRead

这只会检查uri是否有效而不下载实际内容。

HttpClient client = new HttpClient();
var downloadUri = new Uri("https://domainame/someblobcontent.zip");
Task<HttpResponseMessage> response = null;
try
 {
       using (response = client.GetAsync(downloadUri, HttpCompletionOption.ResponseHeadersRead))
            {
                if(response.Result.IsSuccessStatusCode)
                {
                    Console.WriteLine("uri is valid, got response code {0}", response.Result.StatusCode);
                }
                else
                {
                    Console.WriteLine("uri is not valid, got response code {0}", response.Result.StatusCode);
                }
            }
  }
  catch(Exception e)
  {
      Console.WriteLine(e.ToString());
  }