使用twebbrowser在delphi中从网站抓取图像

Question

im trying to make a small tool which downloads all images from the site visited. It have to be made with twebbrowser component. The test site from my customer is Click . At the moment im selecting the pictures with getelementbyid but some of the pictures dont have a id. How can i adress the missing ones? Thanks alot

Answer 1

After the page is loaded, query the TWebBrowser.Document property for the IHTMLDocument2 interface, and then you can enumerate the elements of the IHTMLDocument2.images collection:

var
  Document: IHTMLDocument2;
  Images: IHTMLElementCollection;
  Image: IHTMLImgElement;
  I: Integer;
begin
  Document := WebBrowser1.Document as IHTMLDocument2;
  Images := Document.images;
  For I := 0 to Images.length - 1 do
  begin
    Image := Images.item(I, '') as IHTMLImgElement;
    // use Image as needed...
  end;
end;

Note that this will only find images in HTML <img> tags. If you need to find images in <input type="image"> tags as well, you will have to enumerate the elements of the IHTMLDocument2.all collection looking for instances of the IHTMLInputElement interface whose type property is "image" , eg:

var
  Document: IHTMLDocument2;
  Elements: IHTMLElementCollection;
  Element: IHTMLElement;
  Image: IHTMLImgElement;
  Input: IHTMLInputElement;
  I: Integer;
begin
  Document := WebBrowser1.Document as IHTMLDocument2;
  Elements := Document.all;
  For I := 0 to Elements.length - 1 do
  begin
    Element := Elements.item(I, '') as IHTMLElement;
    if Element is IHTMLImgElement then begin
      Image := Element as IHTMLImgElement;
      // use Image as needed...
    end
    else if Element is IHTMLInputElement then begin
      Input := Element as IHTMLInputElement;
      if Input.type = 'image' then
      begin
        // use Input as needed...
      end;
    end;
  end;
end;

Answer 2

Instead of requesting a specific element by id, you can "walk" the document and look at each element using WebDocument.all.item(itemnum,'').

var
  cAllElements: IHTMLElementCollection;
  eThisElement: IHTMLElement;
  WebDocument: IHTMLDocument2;

=======

 cAllElements:=WebDocument.All
  For iThisElement:=0 to cAllElements.num-1 do
    begin
      eThisElement:=cAllElements.item(iThisElement,'') as IHTMLElement;
      // check out eThisElement and do what you want
    end;

You would then look at the element .tagName for IMG, or do whatever assessment you need in order to determine if it is a picture and handle it as you did before.

Dan