unit1.pas

本光盘是《Delphi 7应用教程》一书的配套光盘

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation
Type
  zjj=(RBall,GBall,BBall); //定义枚举类型

{$R *.dfm}
Function meth(zjf:zjj):String;//自定义函数
begin
  Case zjf of
    RBall:meth:='红';
    GBall:meth:='绿';
    BBall:meth:='蓝';
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  zj1,zj2,zj3:zjj;        //声明枚举变量
  str,str1,str2,str3:String;
begin
  str:='';
  for zj1:=Low(zjj) to High(zjj) do //循环变量为枚举类型
    begin
      str1:=meth(zj1);
      for zj2:=Low(zjj) to High(zjj) do
        begin
          if (zj2<>zj1) then
            begin
              str2:=meth(zj2);
              for zj3:=Low(zjj) to High(zjj) do
                if ((zj3<>zj1)And(zj3<>zj2))then
                  begin
                    str3:=meth(zj3);
                    str:=str+str1+str2+str3+'   ';//找到一种不同颜色的球就添加上
                  end; //此处end语句很多，注意不要漏掉或多写
            end;
        end;
    end;
  if Length(str)>33 then
    begin
      str1:=Copy(str,1,33);         //字符串太长就截取为两段
      str2:=Copy(str,34,Length(str));
      Canvas.TextOut(65,25,'中奖的不同颜色球如下');
      Canvas.TextOut(30,65,str1);
      Canvas.TextOut(30,90,str2);
    end;
end;

end.