patbltu.pas

DelphiWin32核心API参考光盘内容.是学习书籍中的源码,便于学习.

unit PatBltU;

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

{$R *.DFM}
{$R BrshPtrn.Res}

procedure TForm1.Button1Click(Sender: TObject);
var
  BitmapPattern: HBITMAP;     // holds the bitmap brush pattern
  PatternBrush: HBRUSH;       // holds the handle to the patterned brush
  OldBrush: HBRUSH;           // tracks the original brush
begin
  {load a bitmap from the resource file}
  BitmapPattern := LoadBitmap(hInstance, 'BRUSHPATTERN');

  {use it to create a patterned brush}
  PatternBrush := CreatePatternBrush(BitmapPattern);

  {select this new brush into the main form's device context}
  OldBrush := SelectObject(Canvas.Handle, PatternBrush);

  {paint a pattern filled rectangle}
  PatBlt(Canvas.Handle, 0, 0, Width, Height, PATINVERT);

  {replace the original brush handle}
  SelectObject(Canvas.Handle, OldBrush);

  {we no longer need the patterned brush or the bitmap, so delete them}
  DeleteObject(PatternBrush);
  DeleteObject(BitmapPattern);
end;

end.