unit1.pas

来自「《深入Delphi的多媒体编程》实例源代码」· PAS 代码 · 共 52 行

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, 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

{$R *.DFM}

procedure TForm1.Button1Click(Sender: TObject);
var MyColor:Longint;
    x,y:Word;
begin
 MyColor:=$33;{颜色基数}
 with Canvas do
 begin
   {当x坐标在外循环，y坐标在内
循环时，颜色按列逐渐变化；反之则按行变化}
   for x:=0 to Width do
   begin
    if x mod 3=0 then  {每隔4列变化一次颜色}
    begin
       MyColor:=MyColor+1;  {颜色增量为1}
    end;
    for y:=0 to Height do
    begin
      Pixels[x,y]:=RGB(0,0,MyColor);
  {用API函数宏RGB合成颜色}
    end;
   end;
 end;

end;

end.