如何声明包含使用记录作为参数的事件的记录 [英] How to declare record containing events which use record as parameter

问题描述

我试图找出如何声明一个使用对方的记录和一些对象事件。问题不管我声明什么，我有一个未声明的标识符。

I'm trying to figure out how to declare both a record and a number of object events which use each other. The problem is no matter which way I declare them, I have an "undeclared identifier".

所以使用下面的代码，我可以让他们互相使用吗？事件将被用在一个对象中，并且该记录将被传递给对象的构造函数。

So with the code below, can I get them to use each other? The events will be used in an object, and the record will be passed and used into the object's constructor.

  TMyEvent = procedure(Sender: TObject; var Rec: TMyRecord) of object;

  TMyRecord = record
    OnMyEvent: TMyEvent;
  end;

这可能吗？它需要在所有版本的Delphi 7和更高版本中工作。

Is this possible? It needs to work in all versions of Delphi 7 and up.

推荐答案

不幸的是，转发声明只允许用于类而不是记录，所以我知道的唯一方式是使用指针：

Unfortunately forward declarations are only allowed for classes but not records, so the only way I know of is to use pointers:

PMyRecord = ^TMyRecord;

TMyEvent = procedure(Sender: TObject; Rec: PMyRecord) of object;

TMyRecord = record
  OnMyEvent: TMyEvent;
end;

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