首页 / 软件开发 / Delphi / 再学GDI+[29]: TGPPen - 自定义复合画笔 - SetCompoundArray

再学GDI+[29]: TGPPen - 自定义复合画笔 - SetCompoundArray2012-05-03 博客园 万一本例效果图:

代码文件:unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, ExtCtrls;
type
TForm1 = class（TForm）
LabeledEdit1: TLabeledEdit;
RadioGroup1: TRadioGroup;
procedure FormCreate（Sender: TObject）;
procedure FormPaint（Sender: TObject）;
procedure RadioGroup1Click（Sender: TObject）;
procedure LabeledEdit1Change（Sender: TObject）;
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
uses GDIPOBJ, GDIPAPI;
var
arr1: array[0..5] of Single; {用于均分线复合画笔; 数组大小没有限制, 可用动态数 组}
arr2: array[0..3] of Single; {用于粗细线复合画笔; 数组大小没有限制, 可用动态数 组}
procedure TForm1.FormCreate（Sender: TObject）;
begin
{均分线复合画笔; 6 个元素决定 3 条子线; 数组元素为百分比, 应在 0-1 之间}
arr1[0] := 0.00; {第一线起点}
arr1[1] := 0.10; {第一线终点}
arr1[2] := 0.45; {第二线起点}
arr1[3] := 0.55; {第二线终点}
arr1[4] := 0.90; {第三线起点}
arr1[5] := 1.00; {第三线终点}
{粗细线复合画笔; 4 个元素决定 2 条子线; }
arr2[0] := 0.00; {第一线起点}
arr2[1] := 0.50; {第一线终点}
arr2[2] := 0.90; {第二线起点}
arr2[3] := 1.00; {第二线终点}
LabeledEdit1.EditLabel.Caption := "笔宽";
LabeledEdit1.Text := "10";
RadioGroup1.Caption := "线型";
RadioGroup1.Items.CommaText := "单实线,均分线,粗细线";
RadioGroup1.ItemIndex := 0;
end;
procedure TForm1.FormPaint（Sender: TObject）;
var
g: TGPGraphics;
p: TGPPen;
r: TRect;
begin
g := TGPGraphics.Create（Canvas.Handle）;
g.Clear（$FFFFFFFF）;
p := TGPPen.Create（aclCoral）;
p.SetWidth（StrToFloatDef（LabeledEdit1.Text, 10））;
case RadioGroup1.ItemIndex of
1: p.SetCompoundArray（@arr1, Length（arr1））;
2: p.SetCompoundArray（@arr2, Length（arr2））;
end;
g.DrawLine（p, 0, 0, ClientWidth, ClientHeight）;
r := ClientRect;
g.DrawEllipse（p, MakeRect（r））;
InflateRect（r, -ClientWidth div 4, -ClientHeight div 4）;
g.DrawLine（p, 0, 0, ClientWidth, ClientHeight）;
g.DrawRectangle（p, MakeRect（r））;
p.Free;
g.Free;
end;
procedure TForm1.LabeledEdit1Change（Sender: TObject）;
begin
Repaint;
end;
procedure TForm1.RadioGroup1Click（Sender: TObject）;
begin
Repaint;
end;
end.