Delphi語言學習8-類成員（字段和方法）(2)

3.函數重載

type
  T1 = class(TObject)
    procedure Test(I: Integer); overload; virtual;
  end;
  T2 = class(T1)
    procedure Test(S: string); reintroduce; overload;
  end;
SomeObject := T2.Create;
SomeObject.Test('Hello!');       // calls T2.Test
SomeObject.Test(7);              // calls T1.Test

4 構造函數

type
   TShape = class(TGraphicControl)
     private
       FPen: TPen;
       FBrush: TBrush;
       procedure PenChanged(Sender: TObject);
       procedure BrushChanged(Sender: TObject);
     public
       constructor Create(Owner: TComponent); override;
       destructor Destroy; override;
   end;
constructor TShape.Create(Owner: TComponent);
begin
    inherited Create(Owner);     // Initialize inherited parts
    Width := 65;          // Change inherited propertIEs
    Height := 65;
    FPen := TPen.Create;  // Initialize new fIElds
    FPen.OnChange := PenChanged;
    FBrush := TBrush.Create;
    FBrush.OnChange := BrushChanged;
end;