drawer.cs

苏金明编写的《用VB.NET和VC#.NET开发交互式CAD系统》一书的源代码

using System;
using System.Drawing;

namespace Visitor
{
	/// <summary>
	/// Drawer 的摘要说明。
	/// </summary>
	public class Drawer
	{
		public Drawer()
		{
		}

		private int m_Style,m_Width,m_Color;
		private long aPen,oldP;

		public void preDraw(IntPtr hdc)
		{
			//设置画笔参数
			Win32API.SetROP2(hdc, 13);
			m_Style = 0;
			m_Width = 3;
			m_Color = 255;
			//创建画笔
			aPen = Win32API.CreatePen(m_Style, m_Width, m_Color);
			//把画笔选入绘图环境，并返回原来的画笔
			oldP = Win32API.SelectObject(hdc, aPen);
		}

		public void postDraw(Graphics g,IntPtr hdc)
		{
			//把原来的画笔选入绘图环境
			Win32API.SelectObject(hdc, oldP);
			//删除新创建的画笔
			Win32API.DeleteObject(aPen);
			//释放绘图环境句柄
			g.ReleaseHdc(hdc);
		}

		public  void toDraw(Graphics g,CLine line)
		{
			IntPtr hdc= g.GetHdc();
			preDraw(hdc);
			Win32API.LPPOINT  p=new Win32API.LPPOINT();
			//把画笔移动到直线段的起点处
			Win32API.MoveToEx(hdc, 50, 50,p);
			//绘直线段到终点
			Win32API.LineTo(hdc, 200, 200);
			postDraw(g, hdc);
		}

		public  void toDraw(Graphics g,CCircle circle)
		{
			IntPtr hdc= g.GetHdc();
			preDraw(hdc);
			//把空刷子选入绘图环境
			Win32API.SelectObject(hdc, Win32API.GetStockObject(5));
			//绘圆
			Win32API.Ellipse(hdc, 100, 80, 300, 400);
			postDraw(g, hdc);
		}
	}
}