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Get ASP.NET C# 2.0 Website Thumbnail Screenshot

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22 Jul 2010CPOL1 min read 149.8K   6.2K   70   44
How to get a Website/URL thumbnail/screenshot with C#.NET 2.0 in VS 2005.

screenshot.JPG

Sample application screenshot

Introduction

This sample code/website gets the thumbnail/screenshot for a specific URL, giving the browser dimensions and the thumbnail dimensions you want.

Background

Well, tired of search for a method for giving me the screenshot of a URL, and just finding examples of Windows.Forms, with the simple method DrawToBitmap, I just realized that in ASP.NET, that does not work like that, because of Single Thread and Multi Thread; so I used .SetApartmentState(ApartmentState.STA) to make it single threaded.

Using the Code

Just call the method that you want to associate with the ImageUrl of an ASP.NET Image control.

Server-side

Calling with the IHttpHandler Method

C#
ImageBox.ImageUrl = "~/HandlerWSThumb.ashx?url=" + 
   Server.UrlEncode(txtURL.Text).ToLower().ToString() + "&bw=" + 
   txtBW.Text + "&bh=" + txtBH.Text + "&tw=" + 
   txtTW.Text + "&th=" + txtTH.Text;

Calling with the Class Method

C#
Bitmap bmp = ClassWSThumb.GetWebSiteThumbnail(txtURL.Text, Int32.Parse(txtBW.Text), 
             Int32.Parse(txtBH.Text), Int32.Parse(txtTW.Text), 
             Int32.Parse(txtTH.Text));
bmp.Save(Server.MapPath("~") + "/thumbnail.bmp");
ImageBox.ImageUrl = "~/thumbnail.bmp";

//**if Jpeg is the image format you need just replace the 2 lines above for:
//
//bmp.Save(Server.MapPath("~") + "/thumbnail.jpg", ImageFormat.Jpeg);
//ImageBox.ImageUrl = "~/thumbnail.jpg";

//** but don't forget to add the reference
//   to the class in the page 'Default.aspx'(code behind):
//using System.Drawing.Imaging;

Here is the class method code:

C#
using System;
using System.Drawing;
using System.Windows.Forms;
using System.Threading;
using System.IO;

namespace GetWebSiteThumb
{
    public class ClassWSThumb
    {
        public static Bitmap GetWebSiteThumbnail(string Url, int BrowserWidth, 
               int BrowserHeight, int ThumbnailWidth, int ThumbnailHeight)
        {
            return new WSThumb(Url, BrowserWidth, BrowserHeight, 
                   ThumbnailWidth, ThumbnailHeight).GetWSThumb();
        }

        private class WSThumb
        {
            public WSThumb(string Url, int BW, int BH, int TW, int TH) {
                __Url = Url;
                __BrowserWidth = BW;
                __BrowserHeight = BH;
                __ThumbnailWidth = TW;
                __ThumbnailHeight = TH;
            }

            private Bitmap __Bitmap = null;            
            private string __Url = null;
            private int __ThumbnailWidth;
            private int __ThumbnailHeight;
            private int __BrowserWidth;
            private int __BrowserHeight;

            public string Url            {
                get{return __Url;}
                set{__Url = value;}
            }
            
            public Bitmap ThumbnailImage            {
                get{return __Bitmap;}
            }

            public int ThumbnailWidth            {
                get{return __ThumbnailWidth;}
                set{__ThumbnailWidth = value;}
            }

            public int ThumbnailHeight            {
                get {return __ThumbnailHeight;}
                set {__ThumbnailHeight = value;}
            }

            public int BrowserWidth            {
                get{return __BrowserWidth;}
                set{__BrowserWidth = value;}
            }

            public int BrowserHeight            {
                get{return __BrowserHeight;}
                set{__BrowserHeight = value;}
            }

            public Bitmap GetWSThumb()            {
                ThreadStart __threadStart = new ThreadStart(_GenerateWSThumb);
                Thread __thread = new Thread(__threadStart);

                __thread.SetApartmentState(ApartmentState.STA);
                __thread.Start();
                __thread.Join();
                return __Bitmap;
            }

            private void _GenerateWSThumb()            {
                WebBrowser __WebBrowser = new WebBrowser();
                __WebBrowser.ScrollBarsEnabled = false;
                __WebBrowser.Navigate(__Url);
                __WebBrowser.DocumentCompleted += 
                  new WebBrowserDocumentCompletedEventHandler(WebBrowser_DocumentCompleted);
                while (__WebBrowser.ReadyState != WebBrowserReadyState.Complete)
                    Application.DoEvents();
                __WebBrowser.Dispose();
            }

            private void WebBrowser_DocumentCompleted(object sender, 
                         WebBrowserDocumentCompletedEventArgs e)            {
                WebBrowser __WebBrowser = (WebBrowser)sender;
                __WebBrowser.ClientSize = new Size(this.__BrowserWidth, this.__BrowserHeight);
                __WebBrowser.ScrollBarsEnabled = false;
                __Bitmap = new Bitmap(__WebBrowser.Bounds.Width, __WebBrowser.Bounds.Height);
                __WebBrowser.BringToFront();
                __WebBrowser.DrawToBitmap(__Bitmap, __WebBrowser.Bounds);
                
                if (__ThumbnailHeight != 0 && __ThumbnailWidth !=0)
                __Bitmap = (Bitmap)__Bitmap.GetThumbnailImage(
                    __ThumbnailWidth, __ThumbnailHeight, null, IntPtr.Zero);                
            }
        }
    }
}

Here is the IHTTPHandler method code:

C#
using System;
using System.Data;
using System.Web;
using System.Collections;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Drawing;
using System.Drawing.Imaging;
using System.Windows.Forms;
using System.Threading;
using System.IO;
using System.Reflection;

namespace GetWebSiteThumb
{
    /// <summary>
    /// Summary description for $codebehindclassname$
    /// </summary>
    [WebService(Namespace = "http://tempuri.org/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    public class HandlerWSThumb : IHttpHandler
    {
        public void ProcessRequest(HttpContext context)
        {
            Bitmap thumb = null;
            string url = null;
            int bw = 800; //valor por defeito
            int bh = 600; //valor por defeito
            int tw = 0;    // sem thumbnail 
            int th = 0;

            context.Response.ContentType = "image/jpeg";
            if (context.Request["url"] != null)
            {
                if (context.Request["url"].ToString().ToLower().Contains("http://") || 
                       context.Request["url"].ToString().ToLower().Contains("https://"))
                    url = context.Request["url"].ToString();
                else
                    url = "http://" + context.Request["url"].ToString();
            }

            if (context.Request["bw"] != null)
                bw = Int32.Parse(context.Request["bw"].ToString());

            if (context.Request["bh"] != null)
                bh = Int32.Parse(context.Request["bh"].ToString());

            if (context.Request["tw"] != null)
                tw = Int32.Parse(context.Request["tw"].ToString());

            if (context.Request["th"] != null)
                th = Int32.Parse(context.Request["th"].ToString());

            // return context bitmap
            thumb = GetWebSiteThumbnail(url, bw, bh);

            if (tw != 0 && th != 0)
                thumb.GetThumbnailImage(tw, th, null, IntPtr.Zero).Save(
                           context.Response.OutputStream, ImageFormat.Jpeg);
            else
                thumb.Save(context.Response.OutputStream, ImageFormat.Jpeg);

            thumb.Dispose();
        }

        public static Bitmap GetWebSiteThumbnail(string Url, 
                      int BrowserWidth, int BrowserHeight)
        {
            WebsiteThumbnailImage thumbnailGenerator = 
              new WebsiteThumbnailImage(Url, BrowserWidth, BrowserHeight);
            return thumbnailGenerator.GenerateWebSiteThumbnailImage();
        }

        private class WebsiteThumbnailImage
        {
            public WebsiteThumbnailImage(string Url, 
                   int BrowserWidth, int BrowserHeight)
            {
                this.m_Url = Url;
                this.m_BrowserWidth = BrowserWidth;
                this.m_BrowserHeight = BrowserHeight;
            }

            private string m_Url = null;
            public string Url
            {
                get { return m_Url; }
                set { m_Url = value; }
            }

            private Bitmap m_Bitmap = null;
            public Bitmap ThumbnailImage
            {
                get { return m_Bitmap; }
            }

            private int m_BrowserWidth;
            public int BrowserWidth
            {
                get { return m_BrowserWidth; }
                set { m_BrowserWidth = value; }
            }

            private int m_BrowserHeight;
            public int BrowserHeight
            {
                get { return m_BrowserHeight; }
                set { m_BrowserHeight = value; }
            }

            public Bitmap GenerateWebSiteThumbnailImage()
            {
                Thread m_thread = 
                  new Thread(new ThreadStart(_GenerateWebSiteThumbnailImage));
                m_thread.SetApartmentState(ApartmentState.STA);
                m_thread.Start();
                m_thread.Join();
                return m_Bitmap;
            }

            private void _GenerateWebSiteThumbnailImage()
            {
                WebBrowser m_WebBrowser = new WebBrowser();
                m_WebBrowser.ScrollBarsEnabled = false;
                m_WebBrowser.Navigate(m_Url);
                m_WebBrowser.DocumentCompleted += 
                  new WebBrowserDocumentCompletedEventHandler(
                  WebBrowser_DocumentCompleted);
                while (m_WebBrowser.ReadyState != WebBrowserReadyState.Complete)
                    Application.DoEvents();
                m_WebBrowser.Dispose();
            }

            private void WebBrowser_DocumentCompleted(object sender, 
                    WebBrowserDocumentCompletedEventArgs e)
            {
                WebBrowser m_WebBrowser = (WebBrowser)sender;
                m_WebBrowser.ClientSize = new Size(this.m_BrowserWidth, 
                                          this.m_BrowserHeight);
                m_WebBrowser.ScrollBarsEnabled = false;
                m_Bitmap = new Bitmap(m_WebBrowser.Bounds.Width, 
                                      m_WebBrowser.Bounds.Height);
                m_WebBrowser.BringToFront();
                m_WebBrowser.DrawToBitmap(m_Bitmap, m_WebBrowser.Bounds);
                //m_Bitmap = (Bitmap)m_Bitmap.GetThumbnailImage(
                //   m_ThumbnailWidth, m_ThumbnailHeight, null, IntPtr.Zero);
            }
        }

        // Resusable flag
        public bool IsReusable
        {
            get { return false; }
        }
    }
}

Points of Interest

I learn that there are always three ways to do things: the right way, the wrong way, and the best way. I tried to cover the 3 of them ;) As an add-on, you could build a WebService method for returning the thumbnail. Maybe I will edit this article in the near future and put some code in the sample to accomplish it.

History

  • Version 1.0: Upgrades and tips are welcome.
  • Version 1.1: Just added a comment about converting the resulting BMP in the class method to JPEG, after a user asked me to do that.

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
Web Developer Microsky
Portugal Portugal
Software developer since 1986, as a hobby
and since 1998 as a professional

Currently working for Ogilvy S.A.
(Advertinsing media in portugal)

Comments and Discussions

 
Generalportability Pin
abhishek_mys0524-Jan-11 20:05
abhishek_mys0524-Jan-11 20:05 
GeneralRe: portability Pin
Gilberto Francisco14-Mar-11 4:56
Gilberto Francisco14-Mar-11 4:56 
GeneralMy vote of 4 Pin
windmove12-Jan-11 11:16
windmove12-Jan-11 11:16 
QuestionHow can this be a Website? Pin
nige*30-Nov-10 15:42
nige*30-Nov-10 15:42 
AnswerRe: How can this be a Website? Pin
Mohamad4love5-Jun-11 23:40
Mohamad4love5-Jun-11 23:40 
GeneralCapturing full page Pin
diegote17-Nov-10 3:30
diegote17-Nov-10 3:30 
GeneralBlank page Pin
abecedar001759416-Nov-10 3:26
abecedar001759416-Nov-10 3:26 
GeneralMy vote of 5 Pin
domdom500012-Nov-10 0:27
domdom500012-Nov-10 0:27 
Exactly what I was looking for! Thanks
GeneralAttempted to read or write protected memory. Pin
Jonathan Wood16-Oct-10 14:17
Jonathan Wood16-Oct-10 14:17 
GeneralMy vote of 5 Pin
Bigdeak19-Aug-10 1:51
Bigdeak19-Aug-10 1:51 
GeneralMy vote of 5 Pin
jawed.ace17-Aug-10 1:46
jawed.ace17-Aug-10 1:46 
General5 from myside :) Pin
jawed.ace17-Aug-10 1:45
jawed.ace17-Aug-10 1:45 
GeneralMy vote of 5 Pin
jdhforever29-Jul-10 15:36
jdhforever29-Jul-10 15:36 
GeneralThat's good Pin
Yves26-Jul-10 14:53
Yves26-Jul-10 14:53 
QuestionAttach image to an email? Pin
eappell26-Jul-10 5:15
eappell26-Jul-10 5:15 
GeneralMy vote of 5 Pin
eappell26-Jul-10 5:03
eappell26-Jul-10 5:03 
GeneralWeb Browser in server environment. Pin
gstolarov23-Jul-10 8:15
gstolarov23-Jul-10 8:15 
GeneralRe: Web Browser in server environment. Pin
Gilberto Francisco23-Jul-10 9:31
Gilberto Francisco23-Jul-10 9:31 

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