基础OOP问题,关于 property 使用 function & procedure 做成员...(50分)

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs;

type
  TForm1 = class(TForm)
    function Pro_String_Read (const Value: String): String;
    function Pro_String_Write (const Value: String): String;
    property S: String read Pro_String_Read write Pro_String_Write;
    
    //  这个有一个错误: Incompatible types 如何解决，原因是什么？谢谢！～
      
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation
  function TForm1.Pro_String_Read (const Value: String): String;
    begin
    Result := 'The DIY Property is ' + Value;
    end;

  function TForm1.Pro_String_Write (const Value: String): String;
    begin
    Self.Caption := 'The DIY Property is ' + Value;
    end;

{$R *.dfm}

end.