Delphi异形窗口之PNG

 //1.单元内容
 unit UnitAlienForm;
 interface
 uses
   Windows, Forms, Classes, Graphics;
 //从文件加载PNG
 procedure AlienForm_PNGFromFile(AForm : TForm; AFileName : String);
 //从资源加载PNG
 procedure AlienForm_PNGFromResource(AForm : TForm; ResName : String; ResType : PWideChar; Instance : HINST = );
 //从图像对象加载
 procedure AlienForm_PNGFromGraphic(AForm : TForm; AGraphic : TGraphic);
 implementation
 procedure AlienForm_PNGFromFile(AForm : TForm; AFileName : String);
 var
   wic : TWICImage;
 begin
   wic := TWICImage.Create;
   wic.LoadFromFile(AFileName);
   AlienForm_PNGFromGraphic(AForm, wic);
   wic.Free;
 end;
 procedure AlienForm_PNGFromResource(AForm : TForm; ResName : String;ResType : PWideChar; Instance : HINST);
 var
   wic : TWICImage;
   r : TResourceStream;
 begin
   if Instance =  then
     Instance := HInstance;
   r := TResourceStream.Create(Instance, ResName, ResType);
   wic := TWICImage.Create;
   wic.LoadFromStream(r);
   AlienForm_PNGFromGraphic(AForm, wic);
   wic.Free;
   r.Free;
 end;
 procedure AlienForm_PNGFromGraphic(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(, );
   Size.cx := AGraphic.Width;
   Size.cy := AGraphic.Height;
   BlendFunction.BlendOp := AC_SRC_OVER;
   BlendFunction.BlendFlags := ;
   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,
      ,
      @BlendFunction,
      ULW_ALPHA);
   bmp.Free();
 end;
 end.

 //2.调用方法
 procedure TForm2.FormCreate(Sender: TObject);
 begin
   AlienForm_PNGFromFile(Form2, 'E:\未标题.png');
 end;