类引用作为属性 [英] Class Reference as Property

问题描述

Google对于这类搜索毫无用处，因为您会获得数亿个结果，而这些结果绝对与特定问题无关.

Google is useless for these sorts of searches, because you get hundreds of millions of results absolutely none of which relate to the specific question.

问题很简单:

• 是否可以在Delphi中具有类引用属性?
• 如果是，怎么办?

这就是我尝试过的...

Here's what I've tried...

type

  TMyObject = class
    // ...
  end;

  TMyObjectClass = class of TMyObject

  TMyObjectA = class(TMyObject)
    // specifics here
  end;

  TMyObjectB  =class(TMyObject)
    // specifics here
  end;

  TMyComponent = class(TComponent)
  private
    FObjectType: TMyObjectClass;
  published
    property ObjectType: TMyObjectClass read FObjectType write FObjectType;
  end;

上面的代码可以很好地编译，但是对象检查器根本不显示ObjectType属性.

The above code compiles fine, however the Object Inspector does not show the ObjectType property at all.

我的目的(如果您还没有猜到)是为了使它能够从特定的基类中选择一个类的后代，以使相同的组件以不同的方式工作.

My objective here (if you haven't already guessed) is to make it so that I can select a class descendant from a specific base class, to make the same component behave in a different way.

我想这样做，以便组件不需要直接了解子类(它必须是完全模块化的).

I want to do it this way so that the component doesn't need to know about the sub-classes directly (it needs to be fully modular).

让我澄清一下:我不能使用枚举在子类类型之间进行选择，因为组件无法直接链接到子类类型(在这种情况下是可能的)

无论如何...预先感谢！

Anyway... thanks in advance!

推荐答案

您可以找到所有源自特定基类的类:

You can find all classes that descend from a particular base class: Delphi: At runtime find classes that descend from a given base class? and make this a special property with list of values using TPropertyEditor.

这篇关于类引用作为属性的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！