uabout.pas

工廠採購管理系統

unit uabout;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, jpeg, ExtCtrls;
const//定义常量

  WS_EX_LAYERED = $80000;

  AC_SRC_OVER = $0;

  AC_SRC_ALPHA = $1;

  AC_SRC_NO_PREMULT_ALPHA = $1;

  AC_SRC_NO_ALPHA = $2;

  AC_DST_NO_PREMULT_ALPHA = $10;

  AC_DST_NO_ALPHA = $20;

  LWA_COLORKEY = $1;

  LWA_ALPHA = $2;

  ULW_COLORKEY = $1;

  ULW_ALPHA = $2;

  ULW_OPAQUE = $4;
type
  Tfrmabout = class(TForm)
    Image1: TImage;
    Timer1: TTimer;
    procedure FormCreate(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
    procedure Image1DblClick(Sender: TObject);
  private
    { Private declarations }
    i:integer;
  public
    { Public declarations }
  end;
  function SetLayeredWindowAttributes(hwnd:HWND; crKey:Longint; bAlpha:byte; dwFlags:longint ):longint; stdcall; external user32;//函数声明
var
  frmabout: Tfrmabout;

implementation

{$R *.dfm}

procedure Tfrmabout.FormCreate(Sender: TObject);
var l:longint;

begin
  l:=getWindowLong(Handle, GWL_EXSTYLE);

  l := l Or WS_EX_LAYERED;

  SetWindowLong (handle, GWL_EXSTYLE, l);
  i:=255;


//第二个参数是指定透明颜色

//第二个参数为0则使用第四个参数设置alpha值，从0到255

end;

procedure Tfrmabout.Timer1Timer(Sender: TObject);
begin
 if i<=20 then
 begin
    close;
 end;
  SetLayeredWindowAttributes (handle, 0, i, LWA_ALPHA);
   i:=i-5;
end;

procedure Tfrmabout.Image1DblClick(Sender: TObject);
begin
close;
end;

end.