Surprisingly it is extremely easy implementing in Java.
I did the following 2 test codes:
import java.awt.*;
import java.awt.geom.*;
import javax.swing.*;
public class TestShape {
private static class DisplayComponent extends JComponent {
private Shape s;
private GeneralPath p = new GeneralPath();
private Area a;
public DisplayComponent() {
this.setSize( 500, 500 );
this.setPreferredSize( new Dimension( 500, 500 ) );
p.append( new Ellipse2D.Double( 50, 50, 50, 50 ), false );
p.append( new Ellipse2D.Double( 75, 75, 50, 50 ), false );
p.append( new Ellipse2D.Double( 150, 150, 50, 50 ), false );
a = new Area( p );
} // end DisplayComponent
public void paintComponent( Graphics g ) {
Graphics2D g2d= (Graphics2D)g;
g2d.setColor( new Color( 255, 0, 0 ) );
g2d.draw( a );
} // end paintComponent
} // end clas
public static void main( String[] args ) {
JFrame frame = new JFrame();
DisplayComponent c = new DisplayComponent();
frame.getContentPane().add( c );
frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
frame.pack();
frame.show();
} // end main
} // end class TestShape
The corresponding CSharp test program.
using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
namespace TestGraphicsPath
{
/// <summary>
/// Summary description for Form1.
/// </summary>
public class Form1 : System.Windows.Forms.Form
{
private System.Windows.Forms.PictureBox pictureBox1;
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.Container components = null;
public Form1()
{
//
// Required for Windows Form Designer support
//
InitializeComponent();
//
// TODO: Add any constructor code after InitializeComponent call
//
}
/// <summary>
/// Clean up any resources being used.
/// </summary>
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.pictureBox1 = new System.Windows.Forms.PictureBox();
this.SuspendLayout();
//
// pictureBox1
//
this.pictureBox1.Location = new System.Drawing.Point(55, 35);
this.pictureBox1.Name = "pictureBox1";
this.pictureBox1.Size = new System.Drawing.Size(670, 410);
this.pictureBox1.TabIndex = 0;
this.pictureBox1.TabStop = false;
this.pictureBox1.Paint += new
System.Windows.Forms.PaintEventHandler(this.pictur eBox1_Paint);
//
// Form1
//
this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
this.ClientSize = new System.Drawing.Size(832, 553);
this.Controls.Add(this.pictureBox1);
this.Name = "Form1";
this.Text = "Form1";
this.ResumeLayout(false);
}
#endregion
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.Run(new Form1());
}
private void pictureBox1_Paint(object sender,
System.Windows.Forms.PaintEventArgs e)
{
Graphics g = e.Graphics;
GraphicsPath p1 = new GraphicsPath();
GraphicsPath p2 = new GraphicsPath();
GraphicsPath p3 = new GraphicsPath();
p1.AddEllipse( 50, 50, 50, 50 );
p2.AddEllipse( 75, 75, 50, 50 );
p3.AddEllipse( 150, 150, 50, 50 );
Region r = new Region( p1 );
r.Union( p2 );
r.Union( p3 );
g.FillRegion( Brushes.White, r );
}
}
}
For java, Area is the Region equivalent.
Java , you call call graphics.draw( Area ) and it will draw the outline of
the area.
In CSharp, there isn't graphics.draw( Region ) there is only
graphics.Fill( Region )
Thanks. However, I still need help to implement in CSharp.
Regards,
Altramagnus
"Jay B. Harlow [MVP - Outlook]" <Ja************@msn.com> wrote in message
news:Oa**************@tk2msftngp13.phx.gbl...
Altramagnus,
Unfortunately, fortunately actually, I only see that you can create a
Region from a GraphicsPath, and not a GraphicsPath from a Region.
As Charles Petzold in "Programming Microsoft Windows with Microsoft Visual
Basic .NET - Core Reference" from MS Press, suggests that "They (Regions)
might even be ignored altogether if not for the role they play in
clipping". Which makes sense to me, almost every thing I would want to do with a
Region I can directly do with a GraphicsPath, hence my suggestion of using a
GraphicsPath only.
The only way I see to visual get what you want is something like:
Dim path As New GraphicsPath(FillMode.Winding)
path.AddEllipse(50, 50, 50, 50)
path.AddEllipse(75, 75, 50, 50)
path.AddEllipse(150, 150, 50, 50)
e.Graphics.FillPath(SystemBrushes.WindowText, path)
path.Dispose()
If the above is not what you had in mind, you might want to ask "how to
get the outline of a graphics path" in the
microsoft.public.dotnet.framework.drawing newsgroup. As I'm not convinced
that Union of a Region is really what you want, at least it doesn't feel
like how to achieve it.
Hope this helps
Jay
"Altramagnus" <al*********@hotmail.com> wrote in message
news:41******@news.starhub.net.sg... Yes, I got my Region from GraphicsPath.
The reason is I need to get the union.
OK. This is my requirement:
I have n number of circles. Some of them might overlap.
But I need the outline after union all the circles.
Creating GraphicsPath of 1 circle is easy.
But how do I create the graphicsPath of the union shape?
Thanks.
"Jay B. Harlow [MVP - Outlook]" <Ja************@msn.com> wrote in
message news:OU**************@TK2MSFTNGP11.phx.gbl... Altramagnus,
Instead of starting with a Region and creating a GraphicsPath, have
you considered starting with a GraphicsPath and creating a Region?
Or simply using a GraphicsPath only?
Hope this helps
Jay
"Altramagnus" <al*********@hotmail.com> wrote in message
news:41******@news.starhub.net.sg...
> I have a complicated Region object, which I need to draw the
outline, but > not fill
> How can I convert the Region object to GraphicsPath object?
> or How can I draw the outline of the Region object?
>
>
