unit1.pas

有关多媒体的各个细节

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Timer1: TTimer;
    Image1: TImage;
    Button1: TButton;
    Button2: TButton;
    procedure Timer1Timer(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    StartY,tt,l,h:integer;
    PicRect:Trect;
    BmpMap:TBitmap;
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

//循环显示
procedure TForm1.Timer1Timer(Sender: TObject);
begin
 StartY:=StartY-1;
 tt:=tt-1;

//计算显示的纵坐标，并置循环变量
 if StartY>0 then
     tt:=StartY+80
 else
  if StartY<-image1.height then
    StartY:=image1.height+20;

//文字显示处理
 with Image1.Canvas do
  begin
   //第一行文字
   font.size:=18;
   font.color:=clRed;
   TextOut(30,StartY,'电视片尾');
   //第二行文字
   font.size:=12;
   font.color:=clBlue;
   TextOut(30,StartY+50,'字幕演示');

   //填充原来字符串
   l:=textwidth('电视片尾');
   h:=textheight('字幕演示');
   pen.color:=clGreen;
   moveto(30,h+StartY+50-2);
   lineto(30+l,h+StartY+50-2);
  end;

//计算新的图形显示区域，并给予显示
PicRect.topleft.x:=30;
PicRect.topleft.y:=tt;
PicRect.bottomright.x:=PicRect.topleft.x+100;
PicRect.bottomright.y:=PicRect.topleft.y+80;
image1.canvas.stretchdraw(PicRect,BmpMap);

//填充原来图形区域
image1.Canvas.pen.color:=clGreen;
image1.Canvas.moveto(0,PicRect.topleft.y+80);
image1.Canvas.lineto(PicRect.topleft.x+100,PicRect.topleft.y+80);
end;

//初始化程序参数，并开始显示
procedure TForm1.Button1Click(Sender: TObject);
begin
  timer1.enabled:=true;//启动定时器
  timer1.Interval:=10;

  //移动的循环参数
  StartY:=image1.height+20;
  tt:=StartY+80;
  //填充背景色
  image1.Canvas.brush.color:=clGreen;
  PicRect:=Rect(0,0,image1.width,image1.height);
  image1.Canvas.FillRect(PicRect);

  //创建图形对象，并在限定的区域内显示图形
  PicRect:=Rect(-1,-1,1,1);
  BmpMap:=Tbitmap.create;
  BmpMap.loadfromfile('bird.bmp');
  image1.canvas.stretchdraw(PicRect,BmpMap);//缩略显示
end;

//退出
procedure TForm1.Button2Click(Sender: TObject);
begin
 BmpMap.free;//释放图形对象
 Close;
end;

end.