unit1.pas

Delphi源代码--- --卡拉OK模拟器

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    GroupBox1: TGroupBox;
    Panel1: TPanel;
    Edit1: TEdit;
    Timer1: TTimer;
    Label1: TLabel;
    Image1: TImage;
    procedure Edit1KeyDown(Sender: TObject; var Key: Word;
      Shift: TShiftState);
    procedure FormCreate(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

const
 basenum=100;  //覆盖原字符串所需次数

var
  Form1: TForm1;
  str: String;  //显示的文本
  loop: Integer;  //存储计时器触发的次数


implementation

{$R *.dfm}

procedure TForm1.Edit1KeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
 if Key=13 then  //如果按下回车键
  begin
   str:=edit1.Text;
   Image1.Canvas.Brush.Color:=clWhite;
   Image1.Canvas.FillRect(Image1.ClientRect);
   Image1.Canvas.Font.Size:=20;
   Image1.Canvas.Font.Color:=clBlack;
   Image1.Canvas.TextOut(10,10,str);  //输出底色为黑色的文字
   Timer1.Enabled:=True;  //打开计时器
   edit1.Enabled:=False;
  end;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
 str:='';
 loop:=1;
 Image1.Canvas.Font.Name:='黑体';
 Image1.Canvas.Font.Size:=20;
 Image1.Canvas.Font.Color:=clBlack;
 Timer1.Enabled:=False;
end;

procedure TForm1.Timer1Timer(Sender: TObject);
var
 rect1: TRect;
 wid: Integer;
begin
 Image1.Canvas.Font.Name:='黑体';
 Image1.Canvas.Font.Size:=20;
 Image1.Canvas.Font.Color:=clred;
 wid:=Image1.Canvas.TextWidth(str);  //字符串的总宽度
 rect1:=rect(10,10,10+wid*loop div basenum,10+Image1.Canvas.TextHeight(str));
 //拷贝的区域按照loop和basenum的比例来确定
 Image1.Canvas.TextRect(rect1,10,10,str);  //在指定的区域里输出文字
 Inc(loop);  //次数加1
 if loop>basenum then
  begin
   Timer1.Enabled:=False;
   loop:=1;
   edit1.Enabled:=True;
   edit1.SetFocus;  //输入框获得焦点
  end;
end;

end.