mycircle.cs

这是一个用C#编写的画图板程序

using System;
using System.Drawing;
using System.Drawing.Drawing2D;

namespace Painter.Common
{
	/// <summary>
	/// MyCircle 的摘要说明。
	/// </summary>
	[Serializable]
	public class MyCircle : MyItem
	{
		private float x1,y1,x2,y2;
		public float X1
		{
			get
			{
				return x1;
			}
			set
			{
				x1 = value;
			}
		}
		public float Y1
		{
			get
			{
				return y1;
			}
			set
			{
				y1 = value;
			}
		}
		public float X2
		{
			get
			{
				return x2;
			}
			set
			{
				x2 = value;
			}
		}
		public float Y2
		{
			get
			{
				return y2;
			}
			set
			{
				y2 = value;
			}
		}
		// 圆心
		public float X
		{
			get
			{
				return (X1+X2)/2;
			}
		}
		public float Y
		{
			get
			{
				return (Y1+Y2)/2;
			}
		}
		public float Radius {
			get{
				return (Math.Abs(X1-X2))/2;
			}
		}
		public MyCircle(float x1,float y1,float x2,float y2,
			Color bordercolor,float borderwidth,DashStyle borderstyle)
		{
			this.X1 = x1;
			this.Y1 = y1;
			this.X2 = x2;
			this.Y2 = y2;
			this.BorderColor = bordercolor;
			this.BorderWidth = borderwidth;
			this.BorderStyle = borderstyle;
		}
		public override void Draw(Graphics g,Color bgColor)
		{
			Pen pen = new Pen(this.BorderColor,this.BorderWidth);
			pen.DashStyle = this.BorderStyle;
			g.DrawEllipse(pen,X1,Y1,X2-X1,Y2-Y1);
			if (IsSelected) 
			{
				pen.Color = SelectedColor;
				g.DrawEllipse(pen,X1,Y1,X2-X1,Y2-Y1);
			}
			else if (DrawDeSelect)
			{
				pen.Color = BorderColor;
				g.DrawEllipse(pen,X1,Y1,X2-X1,Y2-Y1);

				DrawDeSelect = false;
			}
		}
		public override void Erase(Graphics g,Color bgColor)
		{
			Pen pen = new Pen(bgColor,this.BorderWidth);
			pen.DashStyle = this.BorderStyle;
			g.DrawEllipse(pen,X1,Y1,X2-X1,Y2-Y1);
		}
		public override void Select(Graphics g,Color bgColor)
		{
			IsSelected  = true;;
			this.Draw(g,bgColor);
		}
		public override void DeSelect(Graphics g,Color bgColor)
		{
			IsSelected = false;
			DrawDeSelect = true;
			this.Draw(g,bgColor);
		}
		public override bool Contains(float x, float y)
		{
			double distance = Math.Sqrt(Math.Pow((x-this.X),2)+Math.Pow((y-this.Y),2));
			if (distance < this.Radius + 2 + this.BorderWidth &&
				distance > this.Radius - 2 - this.BorderWidth) {
				return true;
			}
			return false;
		}

		public override void Rotate(Graphics g,float cx,float cy,Color bgColor)
		{
		}
		public override void Move(Graphics g, float ptx_offset, float pty_offset, Color bgColor)
		{
			this.Erase(g,bgColor);
			this.X2 += ptx_offset;
			this.Y2 += pty_offset;
			this.X1 += ptx_offset;
			this.Y1 += pty_offset;
			this.Draw(g,bgColor);
		}

	}
}