myrectangle.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>
	/// MyRectAngle 的摘要说明。
	/// </summary>
	[Serializable]
	public class MyRectAngle : MyItem
	{
		private float x1,y1,x2,y2,x3,y3,x4,y4;
		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;
			}
		}
		public float X3
		{
			get
			{
				return x3;
			}
			set
			{
				x3 = value;
			}
		}
		public float Y3
		{
			get
			{
				return y3;
			}
			set
			{
				y3 = value;
			}
		}
		public float X4
		{
			get
			{
				return x4;
			}
			set
			{
				x4 = value;
			}
		}
		public float Y4
		{
			get
			{
				return y4;
			}
			set
			{
				y4 = value;
			}
		}
		private double l12=0;
		public double L12
		{
			get
			{
				if (l12==0) 
				{
					l12 = Math.Sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1));
				}
				return l12;
			}
		}	
		private double l13=0;
		public double L13
		{
			get
			{
				if (l13==0) 
				{
					l13 = Math.Sqrt((x3-x1)*(x3-x1)+(y3-y1)*(y3-y1));
				}
				return l13;
			}
		}	
		private double l14=0;
		public double L14
		{
			get
			{
				if (l14==0) 
				{
					l14 = Math.Sqrt((x4-x1)*(x4-x1)+(y4-y1)*(y4-y1));
				}
				return l14;
			}
		}	

		public MyRectAngle(float x1,float y1,float x3,float y3,
			Color color,float borderwidth,DashStyle style)
		{
			this.X1 = x1;
			this.Y1 = y1;
			this.X2 = x3;
			this.Y2 = y1;
			this.X3 = x3;
			this.Y3 = y3;
			this.X4 = x1;
			this.Y4 = y3;
			this.BorderColor = color;
			this.BorderWidth = borderwidth;
			this.BorderStyle = style;
		}
		public override void Draw(Graphics g,Color bgColor)
		{
			Pen pen = new Pen(this.BorderColor,this.BorderWidth);
			pen.DashStyle = this.BorderStyle;
			g.DrawPolygon(pen,new PointF[]{
											  new PointF(x1,y1),
											  new PointF(x2,y2),
											  new PointF(x3,y3),
											  new PointF(x4,y4)});
			if (IsSelected) 
			{
				pen.Color = SelectedColor;
				g.DrawPolygon(pen,new PointF[]{
												  new PointF(x1,y1),
												  new PointF(x2,y2),
												  new PointF(x3,y3),
												  new PointF(x4,y4)});
			}
			else if (DrawDeSelect)
			{
				pen.Color = BorderColor;
				g.DrawPolygon(pen,new PointF[]{
												  new PointF(x1,y1),
												  new PointF(x2,y2),
												  new PointF(x3,y3),
												  new PointF(x4,y4)});

				DrawDeSelect = false;
			}		
		}
		public override void Erase(Graphics g,Color bgColor)
		{
			Pen pen = new Pen(bgColor,this.BorderWidth);
			pen.DashStyle = this.BorderStyle;
			g.DrawPolygon(pen,new PointF[]{
				 new PointF(x1,y1),
				 new PointF(x2,y2),
				 new PointF(x3,y3),
				 new PointF(x4,y4)});
		}	
		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)
		{
			if (LineContains(X1,Y1,X2,Y2,x,y,this.BorderWidth)) {
				return true;
			}else if (LineContains(X2,Y2,X3,Y3,x,y,this.BorderWidth)) {
				return true;
			}else if (LineContains(X3,Y3,X4,Y4,x,y,this.BorderWidth)) {
				return true;
			}else if (LineContains(X4,Y4,X1,Y1,x,y,this.BorderWidth)) {
				return true;
			}
			return false;
		}
		public override void Rotate(Graphics g, float cx, float cy ,Color bgColor)
		{
			this.Erase(g,bgColor);
			PointF pt3;
			pt3 = RotateLine(X1,Y1,cx,cy,L13);
			X3 = pt3.X;
			Y3 = pt3.Y;
			double angle34,angle23;
			angle23 = Math.Acos(L12/L13);
			angle34 = Math.Acos(L14/L13);
			double angle13 = Math.Atan((Y3-Y1)/(X3-X1));
			// 如果角度在-PI/2~PI/2之间
			if (X3>X1) 
			{
				X2 = X1+(float)(L12*Math.Cos(angle13+angle23));
				Y2 = Y1+(float)(L12*Math.Sin(angle13+angle23));
				X4 = X1+(float)(L14*Math.Cos(angle13-angle34));
				Y4 = Y1+(float)(L14*Math.Sin(angle13-angle34));
			}
			else
			{
				X2 = X1-(float)(L12*Math.Cos(angle13+angle23));
				Y2 = Y1-(float)(L12*Math.Sin(angle13+angle23));
				X4 = X1-(float)(L14*Math.Cos(angle13-angle34));
				Y4 = Y1-(float)(L14*Math.Sin(angle13-angle34));
			}

			this.Draw(g,bgColor);
		}
		public override void Move(Graphics g, float ptx_offset, float pty_offset, Color bgColor)
		{
			this.Erase(g,bgColor);
			this.X4 += ptx_offset;
			this.Y4 += pty_offset;
			this.X3 += ptx_offset;
			this.Y3 += pty_offset;
			this.X2 += ptx_offset;
			this.Y2 += pty_offset;
			this.X1 += ptx_offset;
			this.Y1 += pty_offset;
			this.Draw(g,bgColor);
		}

	}
}