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;
using System.Drawing.Drawing2D;

namespace 全局坐标
{
	/// <summary>
	/// Form1 的摘要说明。
	/// </summary>
	public class Form1 : System.Windows.Forms.Form
	{
		private System.Windows.Forms.TextBox textBox1;
		/// <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.textBox1 = new System.Windows.Forms.TextBox();
			this.SuspendLayout();
			// 
			// textBox1
			// 
			this.textBox1.Location = new System.Drawing.Point(16, 32);
			this.textBox1.Name = "textBox1";
			this.textBox1.Size = new System.Drawing.Size(88, 21);
			this.textBox1.TabIndex = 0;
			this.textBox1.Text = "";
			// 
			// Form1
			// 
			this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
			this.ClientSize = new System.Drawing.Size(292, 266);
			this.Controls.AddRange(new System.Windows.Forms.Control[] {
																		  this.textBox1});
			this.Name = "Form1";
			this.Text = "Form1";
			this.ResumeLayout(false);

		}
		#endregion

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

		protected override void OnPaint(PaintEventArgs e)
		{
			//本程序建立Ｘ轴正向向右，Ｙ轴正向向上，原点在屏幕中心的全局坐标系
			//使Ｙ轴朝上，需要作相对于Ｘ轴的镜像，变换矩阵为［1,0,0,-1,0,0］
			Graphics g= e.Graphics;
			g.FillRectangle(Brushes.White, this.ClientRectangle);
			g.DrawEllipse(Pens.Black, -100, -100, 200, 200);

			//相对于Ｘ轴进行镜像变换
			Matrix mat=new Matrix(1, 0, 0, -1, 0, 0);
			g.Transform = mat;
			Rectangle rect= this.ClientRectangle;
			int w = rect.Width;
			int h= rect.Height;
			//将原点移到屏幕中心
			g.TranslateTransform(w / 2, -h / 2);

			//以原点为中心，绘一个半径为１００的圆
			//注意：由于相对于Ｘ轴作了镜像变换，所有与上下有关的
			//　　　绘图参数都交换了方向，如左上角变成了左下角
			g.DrawEllipse(Pens.Red, -100, -100, 200, 200);

			g.TranslateTransform(100, 100);
			g.DrawEllipse(Pens.Green, -100, -100, 200, 200);

			g.ScaleTransform(2, 2);
			g.DrawEllipse(Pens.Blue, -100, -100, 200, 200);

		}

		private void Form1_MouseMove(object sender, MouseEventArgs e)
		{
			//在文本框中显示当前点的坐标。屏幕坐标被转换为工作区坐标
			Graphics g = CreateGraphics();
			Rectangle rect= this.ClientRectangle;
			int w = rect.Width;
			int h= rect.Height;
			textBox1.Text = " ";
			textBox1.Text =e.X - w / 2 + "  " + (-(e.Y - h / 2));
		}

	}
}