form1.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;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

namespace GDI_交互绘图2
{
	/// <summary>
	/// Form1 的摘要说明。
	/// </summary>
	public class Form1 : System.Windows.Forms.Form
	{
		/// <summary>
		/// 必需的设计器变量。
		/// </summary>
		private System.ComponentModel.Container components = null;

		public Form1()
		{
			//
			// Windows 窗体设计器支持所必需的
			//
			InitializeComponent();

			//
			// TODO: 在 InitializeComponent 调用后添加任何构造函数代码
			//
		}

		/// <summary>
		/// 清理所有正在使用的资源。
		/// </summary>
		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if (components != null) 
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}

		#region Windows Form Designer generated code
		/// <summary>
		/// 设计器支持所需的方法 - 不要使用代码编辑器修改
		/// 此方法的内容。
		/// </summary>
		private void InitializeComponent()
		{
			this.components = new System.ComponentModel.Container();
			this.Size = new System.Drawing.Size(300,300);
			this.Text = "Form1";
		}
		#endregion

		/// <summary>
		/// 应用程序的主入口点。
		/// </summary>
		[STAThread]
		static void Main() 
		{
			Application.Run(new Form1());
		}

		private float m_StartX, m_StartY;
		private float m_EndX, m_EndY;
		private int m_Step= 0;
		private ArrayList lines=new ArrayList();

		protected override void OnMouseDown(MouseEventArgs e)
		{
			Graphics g= this.CreateGraphics();
			m_Step += 1;
			if (m_Step == 1)
			{
				m_StartX = e.X;
				m_StartY = e.Y;
				m_EndX = e.X;
				m_EndY = e.Y;
			}
			else if (m_Step == 2)
			{
				CLine newline=new CLine(new PointF(m_StartX, m_StartY), 
					new PointF(e.X, e.Y));
				newline.Draw(g);
				lines.Add(newline);
				m_Step = 0;
			}
		}

		protected override void OnMouseMove(MouseEventArgs e)
		{
			Graphics g= this.CreateGraphics();
			float prex, prey;
			float minX, minY;
			float maxX, maxY;
			if (m_Step == 1)
			{
				prex = m_EndX;
				prey = m_EndY;
				minX = Math.Min(m_StartX, m_EndX);
				minY = Math.Min(m_StartY, m_EndY);
				maxX = Math.Max(m_StartX, m_EndX);
				maxY = Math.Max(m_StartY, m_EndY);
				this.Invalidate(new Rectangle((int)minX, (int)minY, 
					(int)(Math.Abs(m_EndX - m_StartX)) + 1, 
					(int)(Math.Abs(m_EndY - m_StartY)) + 1));
				this.Update();
				CLine tempLine=new CLine(new PointF(m_StartX, m_StartY), 
					 new PointF(e.X, e.Y));
				tempLine.Draw(g);
				m_EndX = e.X;
				m_EndY = e.Y;
			}
		}

		protected override void OnPaint(PaintEventArgs e)
		{
			Graphics g= e.Graphics;
			g.FillRectangle(Brushes.White, this.ClientRectangle);
			for (int i = 0;i<=lines.Count - 1;i++)
			{
				(checked((CLine)(lines[i]))).Draw(g);
			}
		}
	}
}