欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页

再学 GDI+[5]: DrawArc - 绘制弧线

程序员文章站 2022-03-31 11:37:03
...
本例效果图:

再学 GDI+[5]: DrawArc - 绘制弧线

代码文件:
unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Panel1: TPanel;
    Label1: TLabel;
    Label2: TLabel;
    SpinEdit1: TSpinEdit;
    SpinEdit2: TSpinEdit;
    procedure FormCreate(Sender: TObject);
    procedure FormPaint(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

uses GDIPOBJ, GDIPAPI;

var
  a1,a2: Integer;

procedure TForm1.FormCreate(Sender: TObject);
begin
  a1 := 0;
  a2 := 360;
  SpinEdit1.Text := IntToStr(a1);
  SpinEdit2.Text := IntToStr(a2);
  SpinEdit1.Increment := 10;
  SpinEdit2.Increment := 10;
  SpinEdit1.OnChange := FormPaint;
  SpinEdit2.OnChange := FormPaint;
end;

procedure TForm1.FormPaint(Sender: TObject);
var
  g: TGPGraphics;
  p: TGPPen;
  x,y,w,h: Integer;
begin
  g := TGPGraphics.Create(Canvas.Handle);
  p := TGPPen.Create(aclRed, 2);
  g.Clear(aclWhite);

  x := ClientWidth div 6;
  y := ClientHeight div 6;
  w := x * 4;
  h := y * 3;
  a1 := StrToIntDef(SpinEdit1.Text, 0);
  a2 := StrToIntDef(SpinEdit2.Text, 360);

  g.DrawArc(p, x, y, w, h, a1, a2);

  g.Free;
  p.Free;
end;

end.

 
 
 
 
 

 

 

  
窗体文件:
object Form1: TForm1
  Left = 0
  Top = 0
  Caption = 'Form1'
  ClientHeight = 184
  ClientWidth = 258
  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 Panel1: TPanel
    Left = 0
    Top = 151
    Width = 258
    Height = 33
    Align = alBottom
    BevelOuter = bvNone
    TabOrder = 0
    ExplicitLeft = 8
    ExplicitTop = 96
    ExplicitWidth = 257
    object Label2: TLabel
      Left = 136
      Top = 8
      Width = 52
      Height = 13
      Caption = #26059#36716#35282#24230':'
    end
    object Label1: TLabel
      Left = 8
      Top = 8
      Width = 52
      Height = 13
      Caption = #36215#22987#35282#24230':'
    end
    object SpinEdit2: TSpinEdit
      Left = 194
      Top = 3
      Width = 55
      Height = 22
      MaxValue = 0
      MinValue = 0
      TabOrder = 0
      Value = 0
    end
    object SpinEdit1: TSpinEdit
      Left = 66
      Top = 3
      Width = 55
      Height = 22
      MaxValue = 0
      MinValue = 0
      TabOrder = 1
      Value = 0
    end
  end
end

 
 
 
 
 

 

 

  

转载于:https://my.oschina.net/hermer/blog/319473