1. Computing

Capturing a Screen Shot of a TWebBrowser Content (Web Page) in Delphi

Taking a Web Site's Screen Shot

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The TWebBrowser Delphi control provides access to the Web browser functionality from your Delphi apps - to allow you to create a customized Web browsing application or to add Internet, file and network browsing, document viewing, and data downloading capabilities to your applications.

Web Page Screen Shot

You might need to programmatically grab the screen shot of the current page loaded in the web browser control.

A screen shot (screen capture) is a copy of the screen's contents that can be saved as a graphics file.
Web Browser screen shot is a graphics copy of the content on the web browser control - usually a web page (document).

The custom function WebBrowserScreenShot will capture the contents of a TWebBrower's client area into a JPEG image and save it to a specified file.

 uses ActiveX;
 
 procedure WebBrowserScreenShot(const wb: TWebBrowser; const fileName: TFileName) ;
 var
   viewObject : IViewObject;
   r : TRect;
   bitmap : TBitmap;
 begin
   if wb.Document <> nil then
   begin
     wb.Document.QueryInterface(IViewObject, viewObject) ;
     if Assigned(viewObject) then
     try
       bitmap := TBitmap.Create;
       try
         r := Rect(0, 0, wb.Width, wb.Height) ;
 
         bitmap.Height := wb.Height;
         bitmap.Width := wb.Width;
 
         viewObject.Draw(DVASPECT_CONTENT, 1, nil, nil, Application.Handle, bitmap.Canvas.Handle, @r, nil, nil, 0) ;
 
         with TJPEGImage.Create do
         try
           Assign(bitmap) ;
           SaveToFile(fileName) ;
         finally
           Free;
         end;
       finally
         bitmap.Free;
       end;
     finally
       viewObject._Release;
     end;
   end;
 end; 
Note: JPEG images are smaller when compared to BMPs - this is why the BMP object is converted to a JPG before saving to the disk.

A sample usage: navigate to a web site in the form's OnCreate event, take the screen shot in the webbrowser's OnNavigateComplete2 event:

 procedure TForm1.FormCreate(Sender: TObject) ;
 begin
   WebBrowser1.Navigate('http://delphi.about.com') ;
 end;
 
 procedure TForm1.WebBrowser1NavigateComplete2(ASender: TObject; const pDisp: IDispatch; var URL: OleVariant) ;
 begin
   WebBrowserScreenShot(WebBrowser1,'c:\WebBrowserImage.jpg') ;
 end; 
Note: the code above saves the "http://delphi.about.com" site's screen shot to a file named WebBrowserImage.jpg on the C drive.
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