用 GDI 操作 EMF 文件[4]: 重绘 EMF

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;

type
TForm1 = class(TForm)
Button1: TButton;
procedure FormCreate(Sender: TObject);
procedure FormDestroy(Sender: TObject);
procedure FormMouseDown(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
procedure FormMouseMove(Sender: TObject; Shift: TShiftState; X, Y: Integer);
procedure FormMouseUp(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
procedure Button1Click(Sender: TObject);
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

var
HMetaFile: HENHMETAFILE;
f: Boolean;
x1,y1: Integer;
R: TRect;

procedure TForm1.FormCreate(Sender: TObject);
const
Path = 'C:\Temp\MyMetaFile.emf';
begin
HMetaFile := GetEnhMetaFile(PChar(Path));
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
DeleteEnhMetaFile(HMetaFile);
end;

procedure TForm1.FormMouseDown(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
begin
f := True;
x1 := X;
y1 := Y;
R := Rect(x1,y1,X,Y);
end;

procedure TForm1.FormMouseMove(Sender: TObject; Shift: TShiftState; X,
Y: Integer);
begin
if not f then Exit;
DrawFocusRect(Canvas.Handle, R);
R := Rect(x1,y1,X,Y);
DrawFocusRect(Canvas.Handle, R);
R := Rect(x1,y1,X,Y);
end;

procedure TForm1.FormMouseUp(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
begin
f := False;
PlayEnhMetaFile(Canvas.Handle, HMetaFile, R);
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
Refresh;
end;

end.

object Form1: TForm1
Left = 0
Top = 0
Caption = 'Form1'
ClientHeight = 206
ClientWidth = 339
Color = clBtnFace
Font.Charset = DEFAULT_CHARSET
Font.Color = clWindowText
Font.Height = -11
Font.Name = 'Tahoma'
Font.Style = []
OldCreateOrder = False
Position = poDesktopCenter
OnCreate = FormCreate
OnDestroy = FormDestroy
OnMouseDown = FormMouseDown
OnMouseMove = FormMouseMove
OnMouseUp = FormMouseUp
PixelsPerInch = 96
TextHeight = 13
object Button1: TButton
Left = 256
Top = 173
Width = 75
Height = 25
Caption = 'Button1'
TabOrder = 0
OnClick = Button1Click
end
end