winform 中实现鼠标框选效果 c#

快来打我* 2022-08-10 11:48 449阅读 0赞

项目中需要实现一个鼠标框选的功能，现在将代码分享出来：

思路：实现三个鼠标事件 MouseDown,MouseMove,MouseUp, 至于框选后需要实现什么功能则可以在MouseUp中调用

完整代码如下：

新建一个winform 窗体程序，修改窗体的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>
            /// 初始化选择框
            /// </summary>
            /// <param name="StartPoint"></param>
            private void DrawStart(Point StartPoint)
            {
                this.Capture = true;
                //指定工作区为整个控件
                Cursor.Clip = RectangleToScreen(new Rectangle(0, 0, ClientSize.Width, ClientSize.Height));
                mouseRect = new Rectangle(StartPoint.X, StartPoint.Y, 0, 0);
            }
            /// <summary>
            /// 在鼠标移动的时改变选择框的大小
            /// </summary>
            /// <param name="p">鼠标的位置</param>
            private void ResizeToRectangle(Point p)
            {
                DrawRectangle();
                mouseRect.Width = p.X - mouseRect.Left;
                mouseRect.Height = p.Y - mouseRect.Top;
                DrawRectangle();
            }
            /// <summary>
            /// 绘制选择框
            /// </summary>
            private void DrawRectangle()
            {
                Rectangle rect = RectangleToScreen(mouseRect);
                ControlPaint.DrawReversibleFrame(rect, Color.White, FrameStyle.Dashed);
            }
        }
    }