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[Obsolete] Image Capture Whole Web Page using C#

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22 Jun 2005CPOL4 min read 910.7K   16.9K   234   206
[Obsolete]Capture whole web pages as a single image using C#.

Sample Image - capture.gif

Introduction

[Obsolete] - I am updating this to say that the below code is obsolete now that modern browsers all have tons of page capture extensions.  I am leaving the code for historical/hysterical sake, but don't waste time trying to implement it.  - Doug

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This article presents a C# routine for capturing an entire web page as an image. Many capture examples show how to grab a screen shot, but do not show how to gather information that is below the scrolling region of an application. The most common example of a scrolling problem or “run-over” program is a web page.

This application grabs the page, plus, as a bonus, it demonstrates how to let the client adjust the size of the image and the quality of the JPEG. It shows how to write the name of the webpage onto the image, draw Standard Resolution Guides, save a bitmap as a JPEG and open the directory where the captures are stored.

Background

In a recent application, I wanted to provide our Quality Assurance testers the ability to capture an entire web page. I wanted them to do this by clicking a button from within a BHO (Browser Helper Object) that is used for another testing task. I also wanted to reduce the size of the capture, because the images are e-mailed and can quickly fill up our mailbox quotas.

Using the code

The easiest way to use this code is to download the source, trim out the code functions that may not be wanted (quality of capture, size of image, URL writing, guides, or the open directory function). After the code is trimmed down and the program can compile without errors, copy the source and its dependencies into the desired project.

The first issue to face when copying the source code into a project is the need to refer SHDocVw.dll and MSHTML.dll. In Visual Studio, go to Project, Add Reference, and then select the COM tab. Now, go down to the Microsoft section and look for "Microsoft Internet Controls". Select it, and then find "Microsoft HTML Object Library" (see the above image).

After adding the references, add these necessary directives into the project. (A few other directives are needed, if the code is not loaded into a form.)

C#
using System.Text;
using System.Runtime.InteropServices;
using System.Diagnostics;
using System.IO;
using System.Drawing.Imaging;
using SHDocVw;
using mshtml;

Import user32 functions

C#
[DllImport("user32.dll", CharSet=CharSet.Auto)]
public static extern IntPtr FindWindowEx(IntPtr parent /*HWND*/, 
  IntPtr next /*HWND*/, string sClassName, IntPtr sWindowTitle);

[DllImport("user32.dll", ExactSpelling=true, CharSet=CharSet.Auto)] 
public static extern IntPtr GetWindow(IntPtr hWnd, int uCmd); 

[DllImport("user32.Dll")]
public static extern void GetClassName(int h, StringBuilder s, int nMaxCount);

[DllImport("user32.dll")]
private static extern bool PrintWindow(IntPtr hwnd, IntPtr hdcBlt, uint nFlags);

public const int GW_CHILD = 5; 
public const int GW_HWNDNEXT = 2;

Find an open browser and assign a browser document for it.

C#
SHDocVw.WebBrowser m_browser = null;
SHDocVw.ShellWindows shellWindows = new SHDocVw.ShellWindowsClass();

//Find first availble browser window.
//Application can easily be modified to loop through and
//capture all open windows.
string filename;
 foreach (SHDocVw.WebBrowser ie in shellWindows)
 {
     filename = Path.GetFileNameWithoutExtension(ie.FullName).ToLower();
     if (filename.Equals("iexplore"))
     {
         m_browser = ie;
         break;
     }
 }
 if (m_browser == null)
 {
     MessageBox.Show("No Browser Open");
     return;
 }

 //Assign Browser Document
 mshtml.IHTMLDocument2 myDoc = (mshtml.IHTMLDocument2)m_browser.Document;

The width and height of the web page must be determined along with the resolution settings of the clients screen.

C#
//Set scrolling on.
myDoc.body.setAttribute("scroll", "yes", 0);

//Get Browser Window Height
int heightsize = (int)myDoc.body.getAttribute("scrollHeight", 0);
int widthsize = (int)myDoc.body.getAttribute("scrollWidth", 0);

//Get Screen Height
int screenHeight = (int)myDoc.body.getAttribute("clientHeight", 0);
int screenWidth = (int)myDoc.body.getAttribute("clientWidth", 0);

To capture the whole web page, fragments of the page will have to be grabbed and stitched together to make the whole page. After the first fragment is captured, the browser is scrolled down for the next capture. As the fragments are captured, they are stitched into a target bitmap. The process is repeated until the whole page is captured. For pages that are wider than the clients screen, the page gets scrolled over horizontally, and then the above process is repeated.

C#
//Get bitmap to hold screen fragment.
Bitmap bm = new Bitmap(screenWidth, screenHeight,
   System.Drawing.Imaging.PixelFormat.Format16bppRgb555);

//Create a target bitmap to draw into.
Bitmap bm2 = new Bitmap(widthsize + URLExtraLeft, heightsize +
   URLExtraHeight - trimHeight,
        System.Drawing.Imaging.PixelFormat.Format16bppRgb555);
Graphics g2 = Graphics.FromImage(bm2);

Graphics g = null;
IntPtr hdc;
Image screenfrag = null;
int brwTop = 0;
int brwLeft = 0;
int myPage = 0;
IntPtr myIntptr = (IntPtr)m_browser.HWND;

//Get inner browser window.
int hwndInt = myIntptr.ToInt32();
IntPtr hwnd = myIntptr;
hwnd = GetWindow(hwnd, GW_CHILD);
StringBuilder sbc = new StringBuilder(256);

//Get Browser "Document" Handle
while (hwndInt != 0)
{
    hwndInt = hwnd.ToInt32();
    GetClassName(hwndInt, sbc, 256);

    if(sbc.ToString().IndexOf("Shell DocObject View", 0) > -1)
    {
        hwnd = FindWindowEx(hwnd, IntPtr.Zero,
            "Internet Explorer_Server", IntPtr.Zero);
        break;
    }
    hwnd = GetWindow(hwnd, GW_HWNDNEXT);
 }

//Get Screen Height (for bottom up screen drawing)
while ((myPage * screenHeight) < heightsize)
{
    myDoc.body.setAttribute("scrollTop", (screenHeight - 5) * myPage, 0);
    ++myPage;
}

//Rollback the page count by one
--myPage;

int myPageWidth = 0;
 while ((myPageWidth * screenWidth) < widthsize)
{
    myDoc.body.setAttribute("scrollLeft", (screenWidth - 5) * myPageWidth, 0);
    brwLeft = (int)myDoc.body.getAttribute("scrollLeft", 0);
    for (int i = myPage; i >= 0; --i)
    {
        //Shoot visible window
        g = Graphics.FromImage(bm);
        hdc = g.GetHdc();
        myDoc.body.setAttribute("scrollTop", (screenHeight - 5) * i, 0);
        brwTop = (int)myDoc.body.getAttribute("scrollTop", 0);
        PrintWindow(hwnd, hdc, 0);
        g.ReleaseHdc(hdc);
        g.Flush();
        screenfrag = Image.FromHbitmap(bm.GetHbitmap());
        g2.DrawImage(screenfrag, brwLeft + URLExtraLeft, brwTop +
           URLExtraHeight);
    }
    ++myPageWidth;
}

Finally, save the above target to a time stamped JPEG file.

Points of Interest

I had a lot of fun and suffered a lot of frustration with this project. The captures are really nice. Try it out on one of the "Code Project" pages.

Not shown in this article, but available in the source is the saving of the file to JPEG. I tried GIF and bitmap, but settled on JPEG for size. The main goal was to be able to e-mail these files without taking up a lot of our mailbox quota.

In the actual application, I have an option to copy the file to the clipboard. I never was able to get the clipboard image into a "device dependent bitmap" state that didn't take up much size. I would copy the image, and then paste it into my Outlook e-mail, only to have the e-mail be about a MB big. When I would open the JPEG in Photoshop, then select it, copy it and paste it into Outlook, the Adobe device dependent bitmap was under 100 KB. The same happened with the simple Windows Paintbrush application.

Because of time constraints, I settled on just copying the JPEG file to Outlook. Any solutions on how to turn a large device independent bitmap into a bitmap with a small memory footprint would be welcomed.

License

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


Written By
Web Developer
United States United States
My experience with programming began with Turbo Pascal while working on my Physics degree back in 1989.

After getting out of school, I used pre-VBA Excel macros to write some really fancy applications to help with the job I was doing. This inspired me to try to write "Windows" programs and to search out Visual Basic 3.0.

I wrote a bunch of small applications and ran them against Access and FoxPro. However, this still wasn't my primary job.

In 1994, I went on my first contract, a 3-month deal that turned into 3-years. I learned a lot more about development. Development was in VB3, VB4 and ASP. I got a chance to admin NT4 and SQL Server 6 and 6.5.

After moving on to another company, I spent another 2 years with VB and then 5 years with Java and JSP.

In March of 2004, I installed Visual Studio 2003. I tasted C#, and became hopelessly addicted.

My other interests are my 3 sons, my wife Smile | :) , metal detecting, yard work, travel and learning new things.

update: Now love SharePoint, PowerShell, JQuery, C#, PHP

location: Atlanta, Georgia

Comments and Discussions

 
GeneralRe: It seems it doesn't work with IE7 Pin
Michael Sync5-Aug-07 23:40
Michael Sync5-Aug-07 23:40 
GeneralRe: It seems it doesn't work with IE7 Pin
michael. zhao7-Sep-07 0:06
michael. zhao7-Sep-07 0:06 
GeneralRe: It seems it doesn't work with IE7 Pin
Daniel Landers10-Apr-08 0:08
Daniel Landers10-Apr-08 0:08 
GeneralRe: It seems it doesn't work with IE7 Pin
omar galeano31-Jul-08 2:39
omar galeano31-Jul-08 2:39 
GeneralSave win form as JPEG format. Pin
Madhavaraok13-Jul-07 0:43
Madhavaraok13-Jul-07 0:43 
QuestionHow to implement same thing in Winforms capturing Pin
Madhavaraok11-Jul-07 21:05
Madhavaraok11-Jul-07 21:05 
GeneralVery nice feature. Can you please do same thing for Winforms Pin
Madhavaraok11-Jul-07 2:13
Madhavaraok11-Jul-07 2:13 
QuestionCan you provide same thing for Windows application Pin
Madhavaraok11-Jul-07 2:10
Madhavaraok11-Jul-07 2:10 
I want same feature in the windows applicaiton. Can you provide same thing for Windows application. Thanks in advance.
AnswerRe: Can you provide same thing for Windows application Pin
Ravi Sant20-Jun-11 1:34
Ravi Sant20-Jun-11 1:34 
GeneralmyDoc.body.getAttribute("clientHeight", 0) - return value Pin
rmandel11-Jun-07 5:37
professionalrmandel11-Jun-07 5:37 
GeneralKnowing when loading is complete Pin
mikemcmeekin4-Apr-07 7:08
mikemcmeekin4-Apr-07 7:08 
GeneralRe: Knowing when loading is complete Pin
Shuriken8717-May-09 18:15
Shuriken8717-May-09 18:15 
GeneralActually dont worry I appear to have this working now Pin
Sacha Barber19-Feb-07 5:43
Sacha Barber19-Feb-07 5:43 
GeneralA simliar idea that I need some help with PLEASE [modified] Pin
Sacha Barber16-Feb-07 23:50
Sacha Barber16-Feb-07 23:50 
GeneralCpatuer Web Image into Excel_Form VB Pin
B.L.Praveen11-Jan-07 22:54
B.L.Praveen11-Jan-07 22:54 
GeneralRe: Cpatuer Web Image into Excel_Form VB Pin
Douglas M. Weems13-Jan-07 10:56
Douglas M. Weems13-Jan-07 10:56 
GeneralInternet Explorer -> doesn't work for this pages Pin
Dorian Darius4-Dec-06 22:09
Dorian Darius4-Dec-06 22:09 
GeneralRe: Internet Explorer -> doesn't work for this pages Pin
Not_Possible19-Dec-06 0:55
Not_Possible19-Dec-06 0:55 
GeneralRe: Internet Explorer -&amp;gt; doesn't work for this pages [modified] Pin
givemempower824-Jan-07 7:02
givemempower824-Jan-07 7:02 
GeneralRe: Internet Explorer -&amp;gt; doesn't work for this pages Pin
Sire40418-Jun-07 23:09
Sire40418-Jun-07 23:09 
QuestionProblem in getting ScreenShot of client computer screen (asp.net) Pin
jitendra kumar rajput1-Dec-06 2:25
jitendra kumar rajput1-Dec-06 2:25 
AnswerRe: Problem in getting ScreenShot of client computer screen (asp.net) Pin
Recep Guzel19-Jan-07 4:30
Recep Guzel19-Jan-07 4:30 
QuestionVery Nice Work. Pin
David Strickland / Swingvote28-Nov-06 3:54
David Strickland / Swingvote28-Nov-06 3:54 
GeneralFirefox Pin
Dorian Darius24-Nov-06 0:11
Dorian Darius24-Nov-06 0:11 
GeneralRe: Firefox Pin
Douglas M. Weems24-Nov-06 14:39
Douglas M. Weems24-Nov-06 14:39 

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