为什么出错

Question

自定义一个类，但出错，我是凭c++的经验写的，可能有什么不对type
.......  TPlate=class
  public
    Width,Height:byte;
    constructor Create(tWidth,tHeight:byte);
  end;implementationconstructor TPlate.Create(tWidth,tHeight:byte);
begin
    Width:=tWidth;
    Height:=tHeight;
end;
procedure TForm1.Button1Click(Sender: TObject);
var
    p1,p2:TPlate;
begin
    p1.Create(1,2);
    p2.Create(3,4);     //执行至此出错，代码窗口下方提示p1,p2尚未初始化    showmessage(inttostr(p1.Width));
    showmessage(inttostr(p1.Height));
end;

Answer 1

var
    p1,p2:TPlate;
begin
    p1:= TPlate.Create(1,2);
    p2:= TPlate.Create(3,4);        showmessage(inttostr(p1.Width));
    showmessage(inttostr(p1.Height));
end;