从谷歌驱动器下载图像

Question

我尝试允许用户从用户的谷歌驱动器中选择图像。 我关注这个文档：https://developers.google.com/picker/docs/。 当我从谷歌（'/drive/v2/files/' + FileId）接收图像 URL 时，我尝试在我的 .NET 代码中下载平铺图像：

var WebRequest = (HttpWebRequest)System.Net.WebRequest.Create(url);
WebRequest.AllowWriteStreamBuffering = true;
WebRequest.Timeout = 30000;
WebRequest.KeepAlive = false;
WebRequest.UserAgent = "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2228.0 Safari/537.36";
WebRequest.AllowAutoRedirect = true;
WebRequest.Headers.Add("Authorization", "Bearer " + token);                 

byte[] Arr;
using (var WebResponse = WebRequest.GetResponse())
{
     using (var Stream = WebResponse.GetResponseStream())
     {
          Arr = Stream.StreamToByteArray();
     }

     WebResponse.Close();
}
return Arr;

但我得到的只是一个空的（白色）网页。使用我从谷歌获得的网址，我可以在浏览器中查看图像，但我无法在我的代码中下载它。

如何下​​载图片？

Answer 1

改用WebClient:

client = new WebClient();
client.Headers.Add("User-Agent", "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2228.0 Safari/537.36");
client.Headers.Add("Authorization", "Bearer " + token); 
client.AllowWriteStreamBuffering = true;
return client.DownloadData(url); /// DownloadData returns a byte array