winform 中實現滑鼠框選效果 c#__c#

項目中需要實現一個滑鼠框選的功能，現在將代碼分享出來：

思路：實現三個滑鼠事件 MouseDown,MouseMove,MouseUp, 至於框選後需要實現什麼功能則可以在MouseUp中調用

完整代碼如下：

建立一個winform 表單程式，修改表單的BehindCode即可。

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;namespace WinfrmMouseFrameSelect{    public partial class MFramSelctDemo : Form    {        private bool mouseIsDown = false;        private Rectangle mouseRect = Rectangle.Empty;        public MFramSelctDemo()        {            InitializeComponent();        }        private void MFramSelctDemo_MouseDown(object sender, MouseEventArgs e)        {            mouseIsDown = true;            DrawStart(e.Location);        }        private void MFramSelctDemo_MouseMove(object sender, MouseEventArgs e)        {            if (mouseIsDown)                ResizeToRectangle(e.Location);        }        private void MFramSelctDemo_MouseUp(object sender, MouseEventArgs e)        {            Capture = false;            Cursor.Clip = Rectangle.Empty;            mouseIsDown = false;            DrawRectangle();            mouseRect = Rectangle.Empty;        }        /// <summary>        /// 初始化選擇框        /// </summary>        /// <param name="StartPoint"></param>        private void DrawStart(Point StartPoint)        {            this.Capture = true;            //指定工作區為整個控制項            Cursor.Clip = RectangleToScreen(new Rectangle(0, 0, ClientSize.Width, ClientSize.Height));            mouseRect = new Rectangle(StartPoint.X, StartPoint.Y, 0, 0);        }        /// <summary>        /// 在滑鼠移動的時改變選擇框的大小        /// </summary>        /// <param name="p">滑鼠的位置</param>        private void ResizeToRectangle(Point p)        {            DrawRectangle();            mouseRect.Width = p.X - mouseRect.Left;            mouseRect.Height = p.Y - mouseRect.Top;            DrawRectangle();        }        /// <summary>        /// 繪製選擇框        /// </summary>        private void DrawRectangle()        {            Rectangle rect = RectangleToScreen(mouseRect);            ControlPaint.DrawReversibleFrame(rect, Color.White, FrameStyle.Dashed);        }    }}