窗體上鼠標移動畫線

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;

 

namespace 鼠標移動畫線

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

 

        private void Form1_Load(object sender, EventArgs e)

        {

 

        }

 

        //MyPoint1, MyPoint2表示鼠標按下和彈起時鼠標的座標位置 

        public Point MyPoint1, MyPoint2;

        public int MyFlag = 0;

 

        private void Form1_MouseUp(object sender, MouseEventArgs e)

        {

            //當鼠標彈起時，設置MyFlag = 0，表示不能畫線 

            this.MyFlag = 0;

        }

 

        private void Form1_MouseMove(object sender, MouseEventArgs e)

        {

            this.Text = "X=" + e.X.ToString() + ",Y=" + e.Y.ToString();

            Graphics g = this.CreateGraphics();

            Pen MyPen = new Pen(Color.Black);

 

            //MyFlag=0表示鼠標彈起，不能進行畫線 

            //當鼠標按下時，設置MyFlag=1表示可以畫線 

            if (this.MyFlag == 0)

                return;

 

            //鼠標移動，每次變換時，MyPoint2都記錄下鼠標的位置，以便進行鼠標移動畫線 

            this.MyPoint2.X = e.X;

            this.MyPoint2.Y = e.Y;

            g.DrawLine(MyPen, MyPoint1.X, MyPoint1.Y, MyPoint2.X, MyPoint2.Y);

 

            //當畫完一條線後（很短的，可以當做一個小點看待），將MyPoint1的座標重置爲此時鼠標的位置 

            MyPoint1.X = e.X;

            MyPoint1.Y = e.Y;

        }

 

        private void Form1_MouseDown(object sender, MouseEventArgs e)

        {

            //鼠標第一次按下時，設置鼠標座標爲第一個點的座標 

            this.MyFlag = 1;

            this.MyPoint1.X = e.X;

            this.MyPoint1.Y = e.Y;

        }

 

        private void button1_Click(object sender, EventArgs e)

        {

            this.MyPoint1.X = 0;

            this.MyPoint1.Y = 0;

 

            this.MyPoint2.X = 90;

            this.MyPoint2.Y = 90;

            Graphics g = this.CreateGraphics();

            float a = 10;

            Pen MyPen = new Pen(Color.Black, a);

            g.DrawLine(MyPen, MyPoint1.X, MyPoint1.Y, MyPoint2.X, MyPoint2.Y);

            g.DrawLine(MyPen, MyPoint2.X, MyPoint1.Y, MyPoint1.X, MyPoint2.Y); 

            g.DrawLine(MyPen, MyPoint2.X, MyPoint2.Y, MyPoint2.X, MyPoint1.Y);

            g.DrawLine(MyPen, MyPoint1.X, MyPoint2.Y, MyPoint1.X, MyPoint1.Y);

         }

    }

}

 

 文章來源：http://blog.csdn.net/hui_shixu/article/details/7738410，這裏表示感謝！