Delphi实现静态变量

C++有静态变量，static关键字描述，其实Delphi也可以做到。

以前一般采用的是const方法来实现，现在的Delphi可以用class关键字来实现。

附代码如下，两种方式具有示例。

unit Unit6;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls;

type
  TTestClass = class
  private
    {$J+}
    const FTest : integer = 0;
    {$J-}
    class var FTest2 : integer;
    function GetTest: integer;
    function GetTest2: integer;
  public
    constructor Create;virtual;

    property Test : integer read GetTest;
    property Test2 : integer read GetTest2;
  end;

  TForm6 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form6: TForm6;

implementation

{$R *.dfm}

{ TTestClass }

constructor TTestClass.Create;
begin
  Inc(FTest);
  Inc(FTest2);
end;

function TTestClass.GetTest: integer;
begin
  Result := FTest;
end;

function TTestClass.GetTest2: integer;
begin
  Result := FTest2;
end;

procedure TForm6.Button1Click(Sender: TObject);
var
  ATest : TTestClass;
begin
  ATest := TTestClass.Create;
  Caption := IntToStr(ATest.GetTest)+':'+IntToStr(ATest.GetTest2);
end;

end.