如何在不使用网络浏览器的情况下渲染 HTML 元素？

发布于 2024-12-18 09:04:47 字数 1801 浏览 5 评论 0原文

有没有一种方法可以在画布上绘制特定的 HTML 元素内容而不使用任何 Web 浏览器控件？

使用此代码，我将元素渲染到表单的画布上（仅作为示例）。
它虽然有效，但这段代码不是一个好的做法 - 请参见下文，为什么...

uses
  SHDocVw, MSHTML;

procedure TForm1.Button1Click(Sender: TObject);
var
  WebBrowser: TWebBrowser;
  HTMLElement: IHTMLElement;
  HTMLRenderer: IHTMLElementRender;
begin
  WebBrowser := TWebBrowser.Create(nil);
  try
    WebBrowser.ParentWindow := Application.Handle;
    WebBrowser.Navigate('https://stackoverflow.com/questions/2975586/good-delphi-blogs');

    while WebBrowser.ReadyState < READYSTATE_COMPLETE do
      Application.ProcessMessages;

    HTMLElement := (WebBrowser.Document as IHTMLDocument3).getElementById('question');
    HTMLRenderer := (HTMLElement as IHTMLElementRender);
    HTMLRenderer.DrawToDC(Canvas.Handle);

  finally
    HTMLElement := nil;
    HTMLRenderer := nil;
    WebBrowser.Free;
  end;
end;

它很糟糕，因为

它使用隐藏的 TWebBrowser 控件，但我想直接通过 IHTMLDocument 界面并在我的自己的画布，
如果我创建并加载 IHTMLDocument 手动，例如这样然后渲染器方法IHTMLElementRender.DrawToDC 不绘制任何内容（也许是因为没有画布用于渲染文档）
更糟糕的是 IHTMLElementRender.DrawToDC 目前已弃用，所以我正在寻找一种在我自己的画布上渲染元素的替代方法

是否有一种干净的方法可以使用 MSHTML 来解决这个问题？

原文

Is there a way how to draw specific HTML element content on a canvas without using any web browser control ?

With this code I'm rendering the element to the form's canvas (just as an example).
It works though, but this code is not a good practice - see below, why...

uses
  SHDocVw, MSHTML;

procedure TForm1.Button1Click(Sender: TObject);
var
  WebBrowser: TWebBrowser;
  HTMLElement: IHTMLElement;
  HTMLRenderer: IHTMLElementRender;
begin
  WebBrowser := TWebBrowser.Create(nil);
  try
    WebBrowser.ParentWindow := Application.Handle;
    WebBrowser.Navigate('https://stackoverflow.com/questions/2975586/good-delphi-blogs');

    while WebBrowser.ReadyState < READYSTATE_COMPLETE do
      Application.ProcessMessages;

    HTMLElement := (WebBrowser.Document as IHTMLDocument3).getElementById('question');
    HTMLRenderer := (HTMLElement as IHTMLElementRender);
    HTMLRenderer.DrawToDC(Canvas.Handle);

  finally
    HTMLElement := nil;
    HTMLRenderer := nil;
    WebBrowser.Free;
  end;
end;

It's bad because

it uses the hidden TWebBrowser control, but I would like to load the HTML document directly through the IHTMLDocument interface and render certain element on my own canvas
if I create and load the IHTMLDocument manually e.g. this way then the renderer method IHTMLElementRender.DrawToDC doesn't paint anything (maybe because there's no canvas for rendering of the document)
even worse is that IHTMLElementRender.DrawToDC is deprecated at this time, so I'm looking for an alternative method for rendering elements on my own canvas

Is there a clean way to solve this using MSHTML ?

分享到QQ

分享到微博