Delphi做异型窗体PNG透明

{*******************************************************}
{ }
{ 异形窗口 }
{ }
{ 2009.12.4 王 锐 }
{ }
{*******************************************************}

unit UnitYXForm;

interface
uses
Windows, Forms, Classes, Graphics;

//从文件加载PNG
procedure YXForm_FromFile(AForm : TForm; AFileName : String);
//从资源加载PNG
procedure YXForm_FromResource(AForm : TForm; ResName : String; ResType : PWideChar; Instance : HINST = 0);
//从图像对象加载
procedure YXForm_FromGraphic(AForm : TForm; AGraphic : TGraphic);

implementation

procedure YXForm_FromFile(AForm : TForm; AFileName : String);
var
wic : TWICImage;
begin
wic := TWICImage.Create;
wic.LoadFromFile(AFileName);
YXForm_FromGraphic(AForm, wic);
wic.Free;
end;

procedure YXForm_FromResource(AForm : TForm; ResName : String;ResType : PWideChar; Instance : HINST);
var
wic : TWICImage;
r : TResourceStream;
begin
if Instance = 0 then
Instance := HInstance;
r := TResourceStream.Create(Instance, ResName, ResType);
wic := TWICImage.Create;
wic.LoadFromStream(r);

YXForm_FromGraphic(AForm, wic);
wic.Free;
r.Free;
end;

procedure YXForm_FromGraphic(AForm : TForm; AGraphic : TGraphic);
var
ptDst, ptSrc: TPoint;
Size: TSize;
BlendFunction: TBlendFunction;
bmp : TBitmap;
begin
bmp := TBitmap.Create;
bmp.Assign(AGraphic);
ptDst := Point(AForm.Left, AForm.Top);
ptSrc := Point(0, 0);
Size.cx := AGraphic.Width;
Size.cy := AGraphic.Height;

BlendFunction.BlendOp := AC_SRC_OVER;
BlendFunction.BlendFlags := 0;
BlendFunction.SourceConstantAlpha := $FF; // 透明度
BlendFunction.AlphaFormat := AC_SRC_ALPHA;

SetWindowLong(AForm.Handle, GWL_EXSTYLE, GetWindowLong(AForm.Handle,
GWL_EXSTYLE) or WS_EX_LAYERED);
UpdateLayeredWindow(AForm.Handle,
AForm.Canvas.Handle,
@ptDst,
@Size,
bmp.Canvas.Handle,
@ptSrc,
0,
@BlendFunction,
ULW_ALPHA);
bmp.Free();
end;

end.

想要用的时候很简单,举个例子:
ff := TForm2.Create(Self);
YXForm_FromFile(ff, 'c:\a.png');
ff.Show;

实现动画也很容易.只要不停地YXForm_FromFile(ff, 'c:\a.png');调用一套动作PNG就可以了.

本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/wr960204/archive/2009/12/04/4941660.aspx