如何在一Panel中，如何拖动一条参考线

[jacksu19]

该参考线平行于Y轴。
当mouseUp时，获取该释放点的x值即可，参考线消失。

类似：[C# 如何用鼠标拖出虚线框，释放鼠标虚框消失，就和在windows桌面上拖动鼠标一样 url=http://topic.csdn.net/u/20071220/17/d40930c4-93d8-41d8-8d64-28d744499ff7.html][/url]
只是拖动的是一条参考线而非矩形框。

[jacksu19]

http://topic.csdn.net/u/20071220/17/d40930c4-93d8-41d8-8d64-28d744499ff7.html 《C# 如何用鼠标拖出虚线框，释放鼠标虚框消失，就和在windows桌面上拖动鼠标一样》

[gomoku]

using System;
using System.ComponentModel;
using System.Drawing;
using System.Windows.Forms;

namespace WindowsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            panel1.MouseMove += new MouseEventHandler(panel1_MouseMove);
        }

        Point lastPoint = new Point(-1, -1);
        void panel1_MouseMove(object sender, MouseEventArgs e)
        {
            if( lastPoint.X >= 0 )DrawReversibleLine( lastPoint );
            lastPoint = e.Location;
            DrawReversibleLine( lastPoint );
        }

        void DrawReversibleLine(Point p)
        {
            ControlPaint.DrawReversibleLine(
                panel1.PointToScreen(new Point(0, p.Y)),
                panel1.PointToScreen(new Point(panel1.Width, p.Y)),
                SystemColors.Control);

            ControlPaint.DrawReversibleLine(
                panel1.PointToScreen(new Point(p.X, 0)),
                panel1.PointToScreen(new Point(p.X, panel1.Height)),
                Color.ForestGreen);
        }
    }
}

[烈火焚身]

学习了

[jacksu19]

万分感谢，让我看到了一线光明和生机。