從背景中的URL下載並顯示圖像

Question

如何使用asp.net從URL下載和顯示圖像

例如，我有一個頁面ShowImage.aspx，當我調用該頁面時，它應該顯示來自外部URL的圖像（來自響應流） https://appharbor.com/assets/images/stackoverflow-logo.png

與Response.ContentType =“ Image / png”

自己解決

    protected void Page_Load(object sender, EventArgs e)
    {
        WebRequest req = WebRequest.Create("https://appharbor.com/assets/images/stackoverflow-logo.png");
        WebResponse response = req.GetResponse();
        Stream stream = response.GetResponseStream();

        Byte[] buffer = null;
        Response.Clear();
        Response.ContentType = "image/png";
        Response.AddHeader("Content-Length", response.ContentLength.ToString());

        int bytesRead = 0;
        do
        {
            buffer = new Byte[4096];
            bytesRead = stream.Read(buffer, 0, buffer.Length);

            if (bytesRead > 0)
            {
                Response.OutputStream.Write(buffer,0,bytesRead);
            }
        } while (bytesRead > 0);
        Response.End();
    }

參考： http : //forums.asp.net/t/1401931.aspx/1

Answer 1

您可以簡單地使用Image控件的Image.ImageUrl屬性

<asp:Image id="img1" runat="server" ImageUrl="https://appharbor.com/assets/images/stackoverflow-logo.png" />

如果要從服務器端設置圖像URL（后面的代碼）

img1.ImageUrl = "http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.image.imageurl.aspx";

如果使用WebRequest從url獲取Image字符串。

WebRequest req = WebRequest.Create("https://appharbor.com/assets/images/stackoverflow-logo.png");
WebResponse response = req.GetResponse();
Stream stream = response.GetResponseStream();
System.Drawing.Image image = System.Drawing.Image.FromStream(stream);
using (MemoryStream ms = new MemoryStream())
{
     image.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
     ms.WriteTo(Response.OutputStream);
}

Answer 2

 public class Service1 : IService1
    {
        public Stream GetImage()
        {
            WebOperationContext.Current.OutgoingResponse.ContentType = "image/jpeg";
            using(WebClient Client = new WebClient())
            {
               using(StreamReader Reader = new StreamReader(Client.OpenRead("FILE URL")))
               {
                 try
                 {
                   string Contents = Reader.ReadToEnd();
                   Reader.Close();
                   return Contents;
                 }
                 catch
                 {
                    return string.Empty;
                 }
               }
            }
        }
    }