本例效果圖:
代碼文件:unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, TeCanvas, ComCtrls;
type
TForm1 = class(TForm)
ComboBox1: TComboBox;
ComboBox2: TComboBox;
TrackBar1: TTrackBar;
ButtonColor1: TButtonColor;
procedure FormCreate(Sender: TObject);
procedure FormPaint(Sender: TObject);
procedure ComboBox1Change(Sender: TObject);
procedure ComboBox2Change(Sender: TObject);
procedure TrackBar1Change(Sender: TObject);
procedure ButtonColor1Click(Sender: TObject);
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
uses GDIPOBJ,GDIPAPI, TypInfo;
var
StartCap, EndCap: Integer;
LineWidth: Single = 2;
LineColor: TGPColor = aclRed;
procedure TForm1.FormCreate(Sender: TObject);
begin
with ComboBox1.Items do
begin
Add('LineCapFlat');
Add('LineCapSquare');
Add('LineCapRound');
Add('LineCapTriangle');
Add('LineCapNoAnchor');
Add('LineCapSquareAnchor');
Add('LineCapRoundAnchor');
Add('LineCapDiamondAnchor');
Add('LineCapArrowAnchor');
Add('LineCapCustom');
end;
ComboBox1.ItemIndex := 0;
ComboBox2.Items := ComboBox1.Items;
ComboBox2.ItemIndex := 0;
TrackBar1.ShowSelRange := False;
TrackBar1.Min := 1;
TrackBar1.Max := 50;
TrackBar1.Position := 2;
ButtonColor1.SymbolColor := clRed;
end;
procedure TForm1.FormPaint(Sender: TObject);
var
g: TGPGraphics;
p: TGPPen;
x1,y1,x2,y2: Integer;
begin
g := TGPGraphics.Create(Canvas.Handle);
p := TGPPen.Create(0);
g.Clear(MakeColor(255,255,255));
x1 := 50;
x2 := ClientWidth - 50;
y1 := ClientHeight p 2;
y2 := y1;
p.SetColor(LineColor);
p.SetWidth(LineWidth);
p.SetStartCap(StartCap);
p.SetEndCap(EndCap);
g.DrawLine(p, x1, y1, x2, y2);
g.Free;
p.Free;
end;
procedure TForm1.ComboBox1Change(Sender: TObject);
var
i: Integer;
begin
i := 0;
case TComboBox(Sender).ItemIndex of
0 : i := LineCapFlat;
1 : i := LineCapSquare;
2 : i := LineCapRound;
3 : i := LineCapTriangle;
4 : i := LineCapNoAnchor;
5 : i := LineCapSquareAnchor;
6 : i := LineCapRoundAnchor;
7 : i := LineCapDiamondAnchor;
8 : i := LineCapArrowAnchor;
9 : i := LineCapCustom;
10: i := LineCapAnchorMask;
end;
if TComboBox(Sender) = ComboBox1 then StartCap := i;
if TComboBox(Sender) = ComboBox2 then EndCap := i;
Repaint;
end;
procedure TForm1.ComboBox2Change(Sender: TObject);
begin
ComboBox1Change(Sender);
end;
procedure TForm1.TrackBar1Change(Sender: TObject);
begin
LineWidth := TrackBar1.Position;
Repaint;
end;
procedure TForm1.ButtonColor1Click(Sender: TObject);
begin
LineColor := ColorRefToARGB(ButtonColor1.SymbolColor);
Repaint;
end;
end.
