Csharp/C Sharp by API/System.Drawing/Region

new Region(GraphicsPath gp)

 
  using System;
  using System.Drawing;
  using System.Drawing.Drawing2D;
  using System.Collections;
  using System.ruponentModel;
  using System.Windows.Forms;
  using System.Data;
  using System.Drawing.Imaging;
  public class Form1 : System.Windows.Forms.Form
  {
    public Form1()
    {
      InitializeComponent();
    }
    private void InitializeComponent()
    {
      this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
      this.ClientSize = new System.Drawing.Size(292, 273);
      this.Text = "";
      this.Resize += new System.EventHandler(this.Form1_Resize);
      this.Paint += new System.Windows.Forms.PaintEventHandler(this.Form1_Paint);
    }
    static void Main() 
    {
      Application.Run(new Form1());
    }
    private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
    {      
      Graphics g = e.Graphics;
      g.FillRectangle(Brushes.White, this.ClientRectangle);
      GraphicsPath gp = new GraphicsPath();
      // Create an open figure
      gp.AddLine(10, 10, 10, 50);
      gp.AddLine(10, 50, 50, 50);
      // Start a new figure
      gp.StartFigure();
      gp.AddLine(60, 10, 60, 50);
      gp.AddLine(60, 50, 100, 50);
      gp.CloseFigure();
      gp.AddEllipse(new Rectangle(110, 10, 40, 40));
      // Create a Region whose boundary is the above GraphicsPath 
      Region reg = new Region(gp);
      g.FillRegion(Brushes.Green, reg);
      reg.Dispose();
      gp.Dispose();
    }
    private void Form1_Resize(object sender, System.EventArgs e)
    {
      Invalidate();
    }
  }

Region.Exclude

 
  using System;
  using System.Drawing;
  using System.Drawing.Drawing2D;
  using System.Collections;
  using System.ruponentModel;
  using System.Windows.Forms;
  using System.Data;
  using System.Drawing.Imaging;
  public class Form1 : System.Windows.Forms.Form
  {
    public Form1()
    {
      InitializeComponent();
    }
    private void InitializeComponent()
    {
      this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
      this.ClientSize = new System.Drawing.Size(292, 273);
      this.Text = "";
      this.Resize += new System.EventHandler(this.Form1_Resize);
      this.Paint += new System.Windows.Forms.PaintEventHandler(this.Form1_Paint);
    }
    static void Main() 
    {
      Application.Run(new Form1());
    }
    private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
    {      
      Graphics g = e.Graphics;
      g.FillRectangle(Brushes.White, this.ClientRectangle);
      Region r = new Region(new Rectangle(30, 30, 30, 60));
      r.Exclude(new Rectangle(40, 40, 10, 10));
      g.FillRegion(Brushes.Orange, r);
      r.Dispose();
    }
    private void Form1_Resize(object sender, System.EventArgs e)
    {
      Invalidate();
    }
  }

Region.IsEmpty

 
  using System;
  using System.Drawing;
  using System.Drawing.Drawing2D;
  using System.Collections;
  using System.ruponentModel;
  using System.Windows.Forms;
  using System.Data;
  using System.Drawing.Imaging;
  public class Form1 : System.Windows.Forms.Form
  {
    public Form1()
    {
      InitializeComponent();
    }
    private void InitializeComponent()
    {
      this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
      this.ClientSize = new System.Drawing.Size(292, 273);
      this.Text = "";
      this.Resize += new System.EventHandler(this.Form1_Resize);
      this.Paint += new System.Windows.Forms.PaintEventHandler(this.Form1_Paint);
    }
    static void Main() 
    {
      Application.Run(new Form1());
    }
    private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
    {      
      Graphics g = e.Graphics;
      g.FillRectangle(Brushes.White, this.ClientRectangle);
      Region r = new Region(new Rectangle(30, 30, 30, 60));
      r.Exclude(new Rectangle(40, 40, 10, 10));
      g.FillRegion(Brushes.Orange, r);
      Console.WriteLine(r.IsEmpty(g) ? " - is empty"
                       : " - is non-empty");
      r.Dispose();
    }
    private void Form1_Resize(object sender, System.EventArgs e)
    {
      Invalidate();
    }
  }

Region.IsInfinite

 
  using System;
  using System.Drawing;
  using System.Drawing.Drawing2D;
  using System.Collections;
  using System.ruponentModel;
  using System.Windows.Forms;
  using System.Data;
  using System.Drawing.Imaging;
  public class Form1 : System.Windows.Forms.Form
  {
    public Form1()
    {
      InitializeComponent();
    }
    private void InitializeComponent()
    {
      this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
      this.ClientSize = new System.Drawing.Size(292, 273);
      this.Text = "";
      this.Resize += new System.EventHandler(this.Form1_Resize);
      this.Paint += new System.Windows.Forms.PaintEventHandler(this.Form1_Paint);
    }
    static void Main() 
    {
      Application.Run(new Form1());
    }
    private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
    {      
      Graphics g = e.Graphics;
      g.FillRectangle(Brushes.White, this.ClientRectangle);
      Region r = new Region(new Rectangle(30, 30, 30, 60));
      r.Exclude(new Rectangle(40, 40, 10, 10));
      g.FillRegion(Brushes.Orange, r);
      Console.WriteLine(r.IsInfinite(g) ? " - is infinite"
                        : " - is finite");
      r.Dispose();
    }
    private void Form1_Resize(object sender, System.EventArgs e)
    {
      Invalidate();
    }
  }

Region.IsVisible

 
  using System;
  using System.Drawing;
  using System.Drawing.Drawing2D;
  using System.Collections;
  using System.ruponentModel;
  using System.Windows.Forms;
  using System.Data;
  using System.Drawing.Imaging;
  public class Form1 : System.Windows.Forms.Form
  {
    public Form1()
    {
      InitializeComponent();
    }
    private void InitializeComponent()
    {
      this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
      this.ClientSize = new System.Drawing.Size(292, 273);
      this.Text = "";
      this.Resize += new System.EventHandler(this.Form1_Resize);
      this.Paint += new System.Windows.Forms.PaintEventHandler(this.Form1_Paint);
    }
    static void Main() 
    {
      Application.Run(new Form1());
    }
    private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
    {      
      Graphics g = e.Graphics;
      g.FillRectangle(Brushes.White, this.ClientRectangle);
      Region r = new Region(new Rectangle(30, 30, 30, 60));
      r.Exclude(new Rectangle(40, 40, 10, 10));
      g.FillRegion(Brushes.Orange, r);
      PointF pf = new PointF(35.0f, 30.0f);
      Console.WriteLine((r.IsVisible(pf) ? " - includes"
                         : " - excludes")
                + " the point (35.0, 50.0)");
      r.Dispose();
    }
    private void Form1_Resize(object sender, System.EventArgs e)
    {
      Invalidate();
    }
  }

Region.Union

 
  using System;
  using System.Drawing;
  using System.Drawing.Drawing2D;
  using System.Collections;
  using System.ruponentModel;
  using System.Windows.Forms;
  using System.Data;
  using System.Drawing.Imaging;
  public class Form1 : System.Windows.Forms.Form
  {
    public Form1()
    {
      InitializeComponent();
    }
    private void InitializeComponent()
    {
      this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
      this.ClientSize = new System.Drawing.Size(292, 273);
      this.Text = "";
      this.Resize += new System.EventHandler(this.Form1_Resize);
      this.Paint += new System.Windows.Forms.PaintEventHandler(this.Form1_Paint);
    }
    static void Main() 
    {
      Application.Run(new Form1());
    }
    private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
    {      
      Graphics g = e.Graphics;
      g.FillRectangle(Brushes.White, this.ClientRectangle);
      Region reg = new Region();
      reg.MakeEmpty();
      GraphicsPath gp = new GraphicsPath();
      gp.AddEllipse(10, 10, 50, 50);
      reg.Union(gp);
      gp.Reset();
      gp.AddLine(40, 40, 70, 10);
      gp.AddLine(70, 10, 140, 140);
      gp.CloseFigure();
      reg.Union(gp);
      reg.Union(new Rectangle(40, 50, 60, 60));
      // Set the clipping region
      g.SetClip(reg, CombineMode.Replace);
      g.FillRectangle(Brushes.Green, this.ClientRectangle);
      gp.Dispose();
      reg.Dispose();
    }
    private void Form1_Resize(object sender, System.EventArgs e)
    {
      Invalidate();
    }
  }