如何使用类助手访问类的严格私有成员? [英] How do I use class helpers to access strict private members of a class?

问题描述

这是一个后续问题:如何隐藏对象的受保护过程?
(我对整个班级助手的概念有点模糊)

假设我有一个类:

type 
TShy = class(TObject) 
strict private
  procedure TopSecret;
private
  procedure DirtyLaundry;  
protected 
  procedure ResistantToChange;
end; 

我知道如果我有源代码，我可以通过在同一单元中添加后代类来访问私有方法.

I know I can access the private method if I have the source code by adding a descendent class in the same unit.

我有两个问题:
- 如何使用类助手来访问 strict private 成员?
- 我可以在单独单元中使用类助手来访问(严格的)私有成员吗?

I have 2 questions:
- How do I employ a class helper to access the strict private member?
- Can I use a class helper in a separate unit to access (strict) private members?

推荐答案

直到(包括 Delphi 10.0 Seattle)，您都可以使用类助手来访问 strict protected 和 strict private 成员，像这样:

Up to, and including Delphi 10.0 Seattle, you can use a class helper to access strict protected and strict private members, like this:

unit Shy;

interface

type
  TShy = class(TObject)
  strict private
    procedure TopSecret;
  private
    procedure DirtyLaundry;
  protected
    procedure ResistantToChange;
  end;

unit NotShy;

interface

uses
  Shy;

type
  TNotShy = class helper for TShy
  public
    procedure LetMeIn;
  end;

implementation

procedure TNotShy.LetMeIn;
begin
  Self.TopSecret;
  Self.DirtyLaundry;
  Self.ResistantToChange;
end;

end.

uses
  ..., Shy, NotShy;

procedure TestShy;
var
  Shy: TShy;
begin
  Shy := TShy.Create;
  Shy.LetMeIn;
  Shy.Free;
end;

但是，从 Delphi 10.1 Berlin 开始，这不再有效！类助手不能再访问 strict protected、strict private 或 private 成员.此功能"实际上是 Embarcadero 现在已在柏林修复的编译器错误.你运气不好.

However, starting with Delphi 10.1 Berlin, this no longer works! Class helpers can no longer access strict protected, strict private or private members. This "feature" was actually a compiler bug that Embarcadero has now fixed in Berlin. You are out of luck.

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