【19】C#实战篇—— C# 绘制点划线，绘制虚线——PointF dxdy，过x点垂直画红色点划线，长度为W，过y点水平画红色点划线，长度为H

这里我的系项目名是 CustomControlExample，From名是DrawLinesForm

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 CustomControlExample
{public partial class DrawLinesForm : Form{private PointF dxdy = new PointF(100, 100); // 示例点private float W = 200; // 线的长度private float H = 200; // 线的长度public DrawLinesForm(){this.Paint += DrawLinesForm_Paint;}private void DrawLinesForm_Paint(object sender, PaintEventArgs e){Graphics g = e.Graphics;using (Pen pen = new Pen(Color.Red)){pen.DashStyle = System.Drawing.Drawing2D.DashStyle.Dash;// 画垂直线PointF startVertical = new PointF(dxdy.X, dxdy.Y - H / 2);PointF endVertical = new PointF(dxdy.X, dxdy.Y + H / 2);g.DrawLine(pen, startVertical, endVertical);// 画水平线PointF startHorizontal = new PointF(dxdy.X - W / 2, dxdy.Y);PointF endHorizontal = new PointF(dxdy.X + W / 2, dxdy.Y);g.DrawLine(pen, startHorizontal, endHorizontal);}}}
}