如何声明两个相互关联的类？

Question

我有一个与此类似的问题,但是在delphi中.

type
  TThreadPopulator = class(TThread)
  private
    _owner:TASyncPopulator; //Undeclared identifier
  end;

type
  TAsyncPopulator = class
  private
    _updater: TThreadPopulator;
  end;

提到的问题的解决方案不适用于delphi

Answer 1

见Forward Declarations and Mutually Dependent Classes文档.

type (* start type section - one unified section "to rule them all" *)
  TAsyncPopulator = class; (* forward declaration *)

  TThreadPopulator = class(TThread)
  private
    _owner:TASyncPopulator;
  end;

  TAsyncPopulator = class (* final declaration - WITHIN that very section where forward declaration was made *)
  private
    _updater: TThreadPopulator;
  end;

使用来源,卢克!您的Delphi安装具有完整的VCL和RTL源,供您阅读,观看和学习.它经常使用这个模板.每次当你问自己"我怎么能做到"时,只要想想"Borland是怎么做的",而且很有可能你已经在Delphi提供的资源中得到了一个现成的例子.