C#功能強大的WinForm標尺與網格

這段時間忙於研究WinForm的標尺與網格,主管要我做的跟PowerDesigner一樣，經過一段時間的研究、實踐、修改，最終達標了，代碼如下。

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Text;
using System.Windows.Forms;
using System.Drawing.PRinting;
using System.Drawing.Drawing2D;
//計算屏幕像素大小和mm大小引用
using System.Runtime.InteropServices;

namespace UntilityControl
{
    public partial class RuleAndGrid : UserControl
    {
        public Control useControl;
        private TextBox lineX=new TextBox();
        private TextBox lineY=new TextBox();
        private TextBox rectangleX=new TextBox();
        private TextBox rectangleY=new TextBox();
        Pen penG = new Pen(Color.Black);
        Pen penL = new Pen(Color.Red);
        Font font = new Font("宋體", 8);
        public RuleAndGrid()
        {
            InitializeComponent();
        }
        public Panel panel1 = new Panel();
        //每毫米占的像素數
        float pxwidth;

        private void RulerAndGrid_Paint(object sender, PaintEventArgs e)
        {
            Graphics PenGraphics = e.Graphics;
            InitializeGraph(PenGraphics);
        }

        private void RulerAndGrid_Load(object sender, EventArgs e)
        {
            panel1.Left = 21;
            panel1.Top = 21;
            panel1.Width = RulerWidth - 42;
            panel1.Height = RulerHeight - 42;
            panel1.BackColor = Color.White;
            panel1.MouseMove += new MouseEventHandler(panel1_MouseMove);
            panel1.MouseUp+=new MouseEventHandler(panel1_MouseUp);
            panel1.Paint+=new PaintEventHandler(panel1_Paint);
            lineX.Width = 1;
            lineX.Height = 14;
            lineX.Top = 6;
            lineX.BackColor = Color.Red;
            lineX.Multiline = true;
            lineX.Visible = false;
            this.Controls.Add(lineX);
            lineY.Width = 14;
            lineY.Height = 1;
            lineY.Left = 6;
            lineY.BackColor = Color.Red;
            lineY.Multiline = true;
            lineY.Visible = false;
            this.Controls.Add(lineY);
            rectangleX.Height = 6;
            rectangleX.Top =14;
            rectangleX.BackColor = Color.Black;
            rectangleX.Multiline = true;
            rectangleX.Visible = false;
            this.Controls.Add(rectangleX);
            rectangleY.Width = 6;
            rectangleY.Left = 14;
            rectangleY.BackColor = Color.Black;
            rectangleY.Multiline = true;
            rectangleY.Visible = false;
            this.Controls.Add(rectangleY);
            this.Controls.Add(panel1);
            Calcsale();
        }
        private void panel1_Paint(object sender, PaintEventArgs e)
        {
            DrawGrid();
        }
        private void panel1_MouseUp(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Right)
            {
                SetProperty sp = new SetProperty();
                sp.rad = this;
                sp.ShowDialog();
            }
            else
            {
                if (useControl != null)
                {
                    useControl.MouseClick +=new MouseEventHandler(useControl_MouseClick);
                    useControl.Top = e.Y;
                    useControl.Left = e.X;
                    panel1.Controls.Add(useControl);
                    panel1.Cursor = Cursors.Default;