本例效果圖:
代碼文件:
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, ExtCtrls;
type
TForm1 = class(TForm)
CheckBox1: TCheckBox;
ColorListBox1: TColorListBox;
procedure FormPaint(Sender: TObject);
procedure ColorListBox1Click(Sender: TObject);
procedure CheckBox1Click(Sender: TObject);
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
procedure TForm1.CheckBox1Click(Sender: TObject);
begin
Repaint;
end;
procedure TForm1.ColorListBox1Click(Sender: TObject);
begin
Self.Color := ColorListBox1.Selected;
end;
procedure TForm1.FormPaint(Sender: TObject);
const
str = 'A';
var
Rgn: HRGN;
x,y: Integer;
begin
Canvas.Font.Size := 120;
Canvas.Font.Style := [fsBold];
SetBkMode(Canvas.Handle, TRANSPARENT);
x := (ClIEntWidth - ColorListBox1.Width - Canvas.TextWidth(str)) div 2;
y := -20;
{建立路徑}
BeginPath(Canvas.Handle);
Canvas.TextOut(x, y, str);
EndPath(Canvas.Handle);
{將路徑轉換為區域}
Rgn := PathToRegion(Canvas.Handle);
{區域顏色取反}
if CheckBox1.Checked then InvertRgn(Canvas.Handle, Rgn);
{繪制}
Canvas.Brush.Color := clSilver;
Canvas.Brush.Style := bsDiagCross;
FillRgn(Canvas.Handle, Rgn, Canvas.Brush.Handle);
Canvas.Brush.Color := clRed;
Canvas.Brush.Style := bsSolid;
FrameRgn(Canvas.Handle, Rgn, Canvas.Brush.Handle, 1, 1);
DeleteObject(Rgn);
end;
end.
窗體文件:
object Form1: TForm1
Left = 366
Top = 269
Caption = 'Form1'
ClIEntHeight = 179
ClIEntWidth = 239
Color = clBtnFace
Font.Charset = DEFAULT_CHARSET
Font.Color = clWindowText
Font.Height = -11
Font.Name = 'Tahoma'
Font.Style = []
OldCreateOrder = False
Position = poDesigned
OnPaint = FormPaint
PixelsPerInch = 96
TextHeight = 13
object CheckBox1: TCheckBox
Left = 32
Top = 152
Width = 97
Height = 25
Caption = #21306#22495#39068#33394#21462#21453
TabOrder = 0
OnClick = CheckBox1Click
end
object ColorListBox1: TColorListBox
Left = 147
Top = 0
Width = 92
Height = 179
Align = alRight
ItemHeight = 16
TabOrder = 1
OnClick = ColorListBox1Click
end
end
