1、ZC：我现在（20190717）查到的 有2中方式画 箭头：（1）在 System.Windows.Controls.Canvas中绘制；（2）在 Graphics上绘制
2、在 System.Windows.Controls.Canvas中绘制
2.1、使用WPF创建画图箭头 - NET未来之路 - 博客园.html（https://www.cnblogs.com/lonelyxmas/p/9844910.html）
ZC：这个文章中未提供完整 代码，相应的代码在 下面的文章中找到了，扣出来了
WPF画箭头 - 百度文库.html（https://wenku.baidu.com/view/cc13b2edaeaad1f346933fc6.html）
2.2、类 代码：
using System; using System.ComponentModel; using System.Windows; using System.Windows.Media; using System.Windows.Input; using System.Windows.Controls; using System.Windows.Shapes; namespace xxxxx.ShapeSHH { public sealed class Arrow : Shape { #region Dependency Properties public static readonly DependencyProperty X1Property = DependencyProperty.Register("X1", typeof(double), typeof(Arrow), new FrameworkPropertyMetadata(0.0, FrameworkPropertyMetadataOptions.AffectsRender | FrameworkPropertyMetadataOptions.AffectsMeasure)); public static readonly DependencyProperty Y1Property = DependencyProperty.Register("Y1", typeof(double), typeof(Arrow), new FrameworkPropertyMetadata(0.0, FrameworkPropertyMetadataOptions.AffectsRender | FrameworkPropertyMetadataOptions.AffectsMeasure)); public static readonly DependencyProperty X2Property = DependencyProperty.Register("X2", typeof(double), typeof(Arrow), new FrameworkPropertyMetadata(0.0, FrameworkPropertyMetadataOptions.AffectsRender | FrameworkPropertyMetadataOptions.AffectsMeasure)); public static readonly DependencyProperty Y2Property = DependencyProperty.Register("Y2", typeof(double), typeof(Arrow), new FrameworkPropertyMetadata(0.0, FrameworkPropertyMetadataOptions.AffectsRender | FrameworkPropertyMetadataOptions.AffectsMeasure)); public static readonly DependencyProperty HeadWidthProperty = DependencyProperty.Register("HeadWidth", typeof(double), typeof(Arrow), new FrameworkPropertyMetadata(0.0, FrameworkPropertyMetadataOptions.AffectsRender | FrameworkPropertyMetadataOptions.AffectsMeasure)); public static readonly DependencyProperty HeadHeightProperty = DependencyProperty.Register("HeadHeight", typeof(double), typeof(Arrow), new FrameworkPropertyMetadata(0.0, FrameworkPropertyMetadataOptions.AffectsRender | FrameworkPropertyMetadataOptions.AffectsMeasure)); #endregion #region CLR Properties [TypeConverter(typeof(LengthConverter))] public double X1 { get { return (double)base.GetValue(X1Property); } set { base.SetValue(X1Property, value); } } [TypeConverter(typeof(LengthConverter))] public double Y1 { get { return (double)base.GetValue(Y1Property); } set { base.SetValue(Y1Property, value); } } [TypeConverter(typeof(LengthConverter))] public double X2 { get { return (double)base.GetValue(X2Property); } set { base.SetValue(X2Property, value); } } [TypeConverter(typeof(LengthConverter))] public double Y2 { get { return (double)base.GetValue(Y2Property); } set { base.SetValue(Y2Property, value); } } [TypeConverter(typeof(LengthConverter))] public double HeadWidth { get { return (double)base.GetValue(HeadWidthProperty); } set { base.SetValue(HeadWidthProperty, value); } } [TypeConverter(typeof(LengthConverter))] public double HeadHeight { get { return (double)base.GetValue(HeadHeightProperty); } set { base.SetValue(HeadHeightProperty, value); } } #endregion #region Overrides protected override Geometry DefiningGeometry { get { // Create a StreamGeometry for describing the shape StreamGeometry geometry = new StreamGeometry(); geometry.FillRule = FillRule.EvenOdd; using (StreamGeometryContext context = geometry.Open()) { InternalDrawArrowGeometry(context); } // Freeze the geometry for performance benefits geometry.Freeze(); return geometry; } } #endregion #region Privates private void InternalDrawArrowGeometry(StreamGeometryContext context) { double theta = Math.Atan2(Y1 - Y2, X1 - X2); double sint = Math.Sin(theta); double cost = Math.Cos(theta); Point pt1 = new Point(X1, this.Y1); Point pt2 = new Point(X2, this.Y2); Point pt3 = new Point( X2 + (HeadWidth * cost - HeadHeight * sint), Y2 + (HeadWidth * sint + HeadHeight * cost)); Point pt4 = new Point( X2 + (HeadWidth * cost + HeadHeight * sint), Y2 - (HeadHeight * cost - HeadWidth * sint)); context.BeginFigure(pt1, true, false); context.LineTo(pt2, true, true); context.LineTo(pt3, true, true); context.LineTo(pt2, true, true); context.LineTo(pt4, true, true); } #endregion } }
2.3、调用的代码：
（1）
private void DrawLeaderLineArrow(Point startPt, Point endPt) { Arrow arrow = new Arrow(); arrow.X1 = startPt.X; arrow.Y1 = startPt.Y; arrow.X2 = endPt.X; arrow.Y2 = endPt.Y; arrow.HeadWidth = 15; arrow.HeadHeight = 5; arrow.Stroke = Brushes.Black; arrow.StrokeThickness = 1; _canvas.Children.Add(arrow); }
（2）
private void DrawLeaderLineArrow(Point startPt, Point endPt) {
InitializeComponent();
Arrow arrow = new Arrow(); arrow.X1 = 50; arrow.Y1 = 50; arrow.X2 = 100; arrow.Y2 = 100; arrow.HeadWidth = 15; arrow.HeadHeight = 5; arrow.Stroke = Brushes.Black; arrow.StrokeThickness = 1; canvas.Children.Add(arrow); }
3、在 Graphics上绘制
3.1、C#的箭头画法 - 孤独的猫 - 博客园.html（https://www.cnblogs.com/djcsch2001/archive/2011/05/07/2039991.html）
private void Form1_Paint(object sender, PaintEventArgs e) { Graphics g = e.Graphics; g.SmoothingMode = SmoothingMode.AntiAlias; g.FillRectangle(Brushes.White, this.ClientRectangle); Pen p = new Pen(Color.Black, 10); p.StartCap = LineCap.Round; p.EndCap = LineCap.ArrowAnchor; g.DrawLine(p, 30, 30, 80, 30); p.Dispose(); }
3.2、C#开发教程--如何绘制箭头 - David.Wang 做你喜欢的事情 - CSDN博客.html（https://blog.csdn.net/wanglixin1999/article/details/41183305）
Graphics g = e.Graphics; g.SmoothingMode = SmoothingMode.AntiAlias; g.FillRectangle(Brushes.White, this.ClientRectangle); Pen p = new Pen(Color.Black, 10); p.StartCap = LineCap.Round; p.EndCap = LineCap.ArrowAnchor; g.DrawLine(p, 30, 30, 80, 30); p.Dispose();
4、WPF绘制箭头 - waiting - CSDN博客.html（https://blog.csdn.net/u012366767/article/details/84857000）
ZC：这篇文章 看起来很牛逼，没细看 不知道什么原理，先记录下...
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