如何声明数组属性? [英] How can I declare an array property?

问题描述

我建立了课堂系统

  TTableSpec=class(Tobject)
  private
    FName : string;
    FDescription : string;
    FCan_add : Boolean;
    FCan_edit : Boolean;
    FCan_delete : Boolean;
    FFields : array[1..100] of TFieldSpec;
  public
    property Name: String read FName;
    property Description: String read FDescription;
    property Can_add : Boolean read FCan_add;
    property Can_edit : Boolean read FCan_edit;
    property Can_delete : Boolean read FCan_delete;
    property Fields : array read FFields;
  end;

因此TableSpec Fields属性中的字段应为字段列表(我使用了TFieldSpec数组).编译后如何组织字段列表(使用或不使用数组)

Thus in TableSpec Fields property shall be the list of fields (I used TFieldSpec array). How to organize the list of fields (using or without using an array) as as a result of compilation I receive an error

[Error] Objects.pas(97): Identifier expected but 'ARRAY' found
[Error] Objects.pas(97): READ or WRITE clause expected, but identifier 'FFields' found
[Error] Objects.pas(98): Type expected but 'END' found
[Hint] Objects.pas(90): Private symbol 'FFields' declared but never used
[Fatal Error] FirstTask.dpr(5): Could not compile used unit 'Objects.pas'

推荐答案

您的行

property Fields : array read FFields;

是无效的语法.应该是

property Fields[Index: Integer]: TFieldSpec read GetField;

其中，GetField是一个(私有)函数，该函数采用一个整数(Index)并返回相应的TFieldSpec，例如

where GetField is a (private) function that takes an integer (the Index) and returns the corresponding TFieldSpec, e.g.,

function TTableSpec.GetField(Index: Integer): TFieldSpec;
begin
  result := FFields[Index];
end;

请参见有关数组属性的文档.

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