代码文件:
unit Unit1;interfaceuses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls;type TForm1 = class(TForm) ListBox1: TListBox; procedure FormCreate(Sender: TObject); procedure FormPaint(Sender: TObject); procedure ListBox1Click(Sender: TObject); end;var Form1: TForm1;implementation{$R *.dfm}uses GDIPOBJ, GDIPAPI;procedure TForm1.FormCreate(Sender: TObject);begin ListBox1.Align := alRight; with ListBox1.Items do begin Add('SmoothingModeInvalid '); Add('SmoothingModeDefault '); Add('SmoothingModeHighSpeed '); Add('SmoothingModeHighQuality'); Add('SmoothingModeNone '); Add('SmoothingModeAntiAlias '); end;end;procedure TForm1.FormPaint(Sender: TObject);var g: TGPGraphics; p: TGPPen;begin g := TGPGraphics.Create(Canvas.Handle); p := TGPPen.Create(aclRed, 2); g.SetSmoothingMode(ListBox1.ItemIndex - 1); g.DrawEllipse(p, 10, 10, ClientWidth - ListBox1.Width - 20, ClientHeight - 20); g.DrawLine(p, 0, 0, ClientWidth - ListBox1.Width, ClientHeight); g.DrawLine(p, ClientWidth - ListBox1.Width, 0, 0, ClientHeight); p.Free; g.Free;end;procedure TForm1.ListBox1Click(Sender: TObject);begin Repaint;end;end. 窗体文件: object Form1: TForm1 Left = 0 Top = 0 Caption = 'Form1' ClientHeight = 108 ClientWidth = 286 Color = clBtnFace Font.Charset = DEFAULT_CHARSET Font.Color = clWindowText Font.Height = -11 Font.Name = 'Tahoma' Font.Style = [] OldCreateOrder = False Position = poDesktopCenter OnCreate = FormCreate OnPaint = FormPaint PixelsPerInch = 96 TextHeight = 13 object ListBox1: TListBox Left = 133 Top = 8 Width = 145 Height = 73 ItemHeight = 13 TabOrder = 0 OnClick = ListBox1Click endend绘图质量参数:
SmoothingModeInvalid = -1; {指定一个无效模式}SmoothingModeDefault = 0; {指定不消除锯齿}SmoothingModeHighSpeed = 1; {指定高速度、低质量呈现}SmoothingModeHighQuality = 2; {指定高质量、低速度呈现}SmoothingModeNone = 3; {指定不消除锯齿}SmoothingModeAntiAlias = 4; {指定消除锯齿的呈现}