Add Help to Your Application/zh CN

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Revision as of 05:32, 23 December 2020 by Robsean (talk | contribs) (创建帮助一个条目)

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LCL带来一个帮助系统,允许你 为你自己的应用程序来创建帮助


在 examples/helphtml/中打开示例。



这里是一个非常好的演示 (,38487.msg261731.html#msg261731


LCL帮助包含两部分: 帮助数据库和查看器. 帮助数据库包含关键字 (ID, node, message, pascal, ...) 到帮助页面 (or help web site or...). 帮助查看器嗲用数据库向用户显示帮助信息.

  • A THelpDatabase manages content. It can be a collection of HTML pages or fpdoc XML files or a CHM file or a database or whatever.
  • A THelpViewer is a component that shows help content. For example a viewer for the mime type text/html can start a web browser.

当请求帮助时,the LCL queries each registered THelpDatabase and each database can return a list of entries. If several entries are returned, the LCL asks the user to choose an entry. Then the LCL asks the database to show the help for the entry. The database extracts the help content and asks the LCL for a viewer that supports the mime type of the content. Finally, the viewer shows the help content.


Context-sensitive CHM application help can be used from Lazarus 1.0 and later.

A demonstration program is included that shows how to include context-sensitive help using CHM and the lhelp CHM viewer (the same one that is used for IDE help by default). Please see ${lazarusdir}/components/chmhelp/democontrol/.

你可以写你自己的CHM文件,例如,with the now ancient Microsoft HTML Workshop or with the new Lazarus chmmaker tools in $(lazarusdir)/tools/chmmaker You can use a TCHMHelpDatabase control like the THTMLHelpDatabase control described below.

The advantages of using the CHM system are a smaller, self contained help file instead of multiple files. On the other hand, not every system has a CHM viewer installed by default, so you might want to include lhelp, a CHM viewer written in Pascal and included with the Lazarus sources (components/chmhelp/lhelp/lhelp.lpi).


  • 在你的窗体上放置一个TLHelpConnector
  • Set LHelpPath with the name and location of the LHelp executable (this can be absolute, or relative to the application directory)
  • Set AutoRegister to true
// Example with both chm file and LHelp.exe in Application folder.
Procedure TForm1.FormCreate(Sender: TObject);
  If FileExists(ChangeFileExt(Application.ExeName, '.chm')) Then
    CHMHelpDatabase1.Filename := ChangeFileExt(Application.ExeName, '.chm');
    CHMHelpDatabase1.Keyword := 'test';

    LHelpConnector1.LHelpPath := IncludeTrailingBackSlash(ExtractFileDir(Application.ExeName)) + 'lhelp.exe';
    mnuHelpMain.Enabled := False;

Procedure TForm1.Button1Click(Sender: TObject);
  If mnuHelpMain.Enabled Then  
    //ShowTableOfContents;  (Not implemented for TCHMHelpDatabase)


The LCL provides two components to use HTML files for help: THTMLHelpDatabase and THTMLBrowserHelpViewer. To see the HTML help, see the lazarus example examples/helphtml/htmlhelp1.lpi.


Lazarus help items


  • 在一个窗体上放置一个THTMLHelpDatabase
  • 设置AutoRegister为 true 。
  • 设置KeywordPrefixhtml/ 。它意味着所有关键字都必须以字符串html/为开头。
  • 设置BaseURLfile://yourhelp/。这将在子文件夹yourhelp中搜索HTML文件。你可以具体指定完整的路径(像:file:///usr/lib/yourhelp/)或者一个URL(像:。
  • 在窗体上放置一个THTMLBrowserHelpViewer。这个组件可以启动用户的默认浏览器。
  • 设置AutoRegister为 true 。


  • 现在创建子文件夹yourhelp,并创建一个html页面 yourhelp/edit1.html. In case of a website, the help page should be accesible as
  • 在一个窗体上放置一个TEdit。
  • 设置HelpTypehtKeyword
  • 设置HelpKeywordhtml/edit1.html

When running the program you can focus the edit and press F1 to invoke the help. Under macOS the help key is Cmd-? (or Cmd+Shift+? depending on you keyboard layout). Note: Some window managers, widget set combinations do not pass F1 to the LCL.

INF (using fpGUI's DocView help viewer)

See the message and example project included in the Lazarus Forums. [1]

It shows a fully working example of an LCL application using fpGUI's DocView help viewer. It shows context sensitive help and general help.


  • Set focus to a specific control and press F1. It will show the help topic for that specific control.
  • Click the Help button and it will show the help topic for the dialog/form.
  • Select the "Help -> Show Help" menu item and it will show the general application help and display the first topic in the help file.

See also