再学 GDI+[29]: TGPPen - 自定义复合画笔 - SetCompoundArray

本例效果图:

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代码文件:

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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.


 
   

窗体文件:

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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

  OnPaint = FormPaint

  PixelsPerInch = 96

  TextHeight = 13

  object LabeledEdit1: TLabeledEdit

    Left = 264

    Top = 19

    Width = 67

    Height = 21

    EditLabel.Width = 61

    EditLabel.Height = 13

    EditLabel.Caption = 'LabeledEdit1'

    TabOrder = 0

    OnChange = LabeledEdit1Change

  end

  object RadioGroup1: TRadioGroup

    Left = 264

    Top = 46

    Width = 67

    Height = 66

    Caption = 'RadioGroup1'

    TabOrder = 1

    OnClick = RadioGroup1Click

  end

end