using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using System.IO;using System.Configuration;namespace WFApp2{  public partial class data : Form  {    public data()    {      InitializeComponent();      //窗體      g = this.CreateGraphics();      //chart控件      g2 = this.chart1.CreateGraphics();    }       public Point firstPoint = new Point(0, 0); //鼠標第一點     public Point secondPoint = new Point(0, 0); //鼠標第二點     public bool begin = false;  //是否開始畫矩形     /// <summary>    /// 在from上畫矩形    /// </summary>    Graphics g;    /// <summary>    /// 在chart1控件上畫矩形    /// </summary>    Graphics g2;    /// <summary>    /// 在窗體上按下鼠標事件    /// </summary>    /// <param name="sender"></param>    /// <param name="e"></param>    private void data_MouseDown(object sender, MouseEventArgs e)    {      begin = true;      firstPoint = new Point(e.X, e.Y);    }    /// <summary>    /// 在窗體上鼠標移動開始繪圖    /// </summary>    /// <param name="sender"></param>    /// <param name="e"></param>    private void data_MouseMove(object sender, MouseEventArgs e)    {      if (begin)      {        //清除窗體繪圖面,相當于刷新了一次窗體界面然后重新繪制        g.Clear(this.BackColor);        //獲取新的右下角坐標         secondPoint = new Point(e.X, e.Y);        //獲取兩個數中的大者或小者        int minX = Math.Min(firstPoint.X, secondPoint.X);        int minY = Math.Min(firstPoint.Y, secondPoint.Y);        int maxX = Math.Max(firstPoint.X, secondPoint.X);        int maxY = Math.Max(firstPoint.Y, secondPoint.Y);        //畫框         g.DrawRectangle(new Pen(Color.Red), minX, minY, maxX - minX, maxY - minY);        //ControlPaint.DrawReversibleFrame(new Rectangle(minX, minY, maxX - minX, maxY - minY),this.BackColor,FrameStyle.Dashed);      }    }    /// <summary>    /// 鼠標松開停止繪圖    /// </summary>    /// <param name="sender"></param>    /// <param name="e"></param>    private void data_MouseUp(object sender, MouseEventArgs e)    {      begin = false;    }    /// <summary>    /// 在chart控件上移動鼠標繪圖    /// </summary>    /// <param name="sender"></param>    /// <param name="e"></param>    private void chart1_MouseMove(object sender, MouseEventArgs e)    {      if (begin)      {        //重新在chart上面繪圖，此處不能用clear方法，clear會清除整個繪圖界面chart控件會被清除        this.Refresh();        //獲取新的右下角坐標         secondPoint = new Point(e.X, e.Y);        int minX = Math.Min(firstPoint.X, secondPoint.X);        int minY = Math.Min(firstPoint.Y, secondPoint.Y);        int maxX = Math.Max(firstPoint.X, secondPoint.X);        int maxY = Math.Max(firstPoint.Y, secondPoint.Y);        //畫矩形        g2.DrawRectangle(new Pen(Color.Red), minX, minY, maxX - minX, maxY - minY);      }    }    /// <summary>    /// 鼠標松開停止繪圖    /// </summary>    /// <param name="sender"></param>    /// <param name="e"></param>    private void chart1_MouseUp(object sender, MouseEventArgs e)    {      begin = false;    }    /// <summary>    /// 在chart控件上按下鼠標    /// </summary>    /// <param name="sender"></param>    /// <param name="e"></param>    private void chart1_MouseDown(object sender, MouseEventArgs e)    {      begin = true;      firstPoint = new Point(e.X, e.Y);    }  }}