main.pas

delphi的学习资料

{
  Class 例
}

unit Main;

interface

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

type
  TfmMain = class(TForm)
    btnArea: TBitBtn;
    edtDia: TEdit;
    btnSetDia: TBitBtn;
    LbArea: TLabel;
    btnGetDia: TButton;
    LbDia: TLabel;
    procedure btnAreaClick(Sender: TObject);
    procedure btnSetDiaClick(Sender: TObject);
    procedure btnSetDia2Click(Sender: TObject);
    procedure FormActivate(Sender: TObject);
    procedure btnGetDiaClick(Sender: TObject);
  private    { Private declarations }
  public     { Public declarations }
  end;

var
  fmMain: TfmMain;



////////////////////////////////////////////////////////////////////////////////
implementation
{$R *.dfm}


procedure TfmMain.FormActivate(Sender: TObject);
begin
  circ0:=TCircle.Create();
  edtDia.Text:=FloatToStr(circ0.dia);
end;

//============================================================================
procedure TfmMain.btnAreaClick(Sender: TObject);
var
  n: Single;
begin
  n:=circ0.GetArea();
  LbArea.Caption:=FormatFloat('0.###',n);
end;

//============================================================================
procedure TfmMain.btnSetDiaClick(Sender: TObject);
var
  n: Single;
begin
  n:=StrToInt(edtDia.Text);
  circ0.SetDia(n);
  LbArea.Caption:='???';
end;

//============================================================================
procedure TfmMain.btnSetDia2Click(Sender: TObject);
var
  n: Single;
begin
  n:=StrToInt(edtDia.Text);
  circ0.dia:=n;
end;

//============================================================================
procedure TfmMain.btnGetDiaClick(Sender: TObject);
var tt: single;
begin
  tt:=circ0.GetDia();
  LbDia.Caption:=FloatToStr(tt);
end;


end.