准备工作，WPF的界面这里就不涉及了，完全是代码工作。

首先，我们要做图必须有个容器，如果你要画画必须有纸张一样。这里我们声明一个Canvas作为容器。

代码如下：

Canvas mainPanel = new Canvas(); public DrawLine() { InitializeComponent(); // Add path shape to the UI. this.Content = mainPanel; }

 

总的来说画直线有三种方法：

1。使用LineGeometry，实例代码如下

/// <summary> /// 绘制线段 /// </summary> protected void DrawingLine(Point startPt,Point endPt) { LineGeometry myLineGeometry = new LineGeometry(); myLineGeometry.StartPoint = startPt; myLineGeometry.EndPoint = endPt; Path myPath = new Path(); myPath.Stroke = Brushes.Black; myPath.StrokeThickness = 1; myPath.Data = myLineGeometry; mainPanel.Children.Add(myPath); }

这个很简单，就不多作解释了。

2。使用 LineSegment

我们使用LineSegment时，因为它不是geometry的扩展类，所以需要一个包装：PathGeometry才能将它付给path坐Data进而呈现在Canvas上。但是麻烦的是PathGeometry不能直接包容segment，它所包容的是PathFigure，所以我们还需一个中间层。msdn的解释是：

PathGeometry 使用的语法比简单的 LineGeometry 使用的语法要详细得多，在本例中使用 LineGeometry 类可能更有效，但是使用 PathGeometry 的详细语法可以创建极其复杂的几何区域。也就是说使用PathGeometry可以轻松构建更复杂的图形。

代码如下：

// Create a figure that describes a // line from (10,20) to (100,130). PathFigure myPathFigure = new PathFigure(); myPathFigure.StartPoint = new Point(10,20); myPathFigure.Segments.Add( new LineSegment(new Point(100,130), true /* IsStroked */ )); /// Create a PathGeometry to contain the figure. PathGeometry myPathGeometry = new PathGeometry(); myPathGeometry.Figures.Add(myPathFigure); // Display the PathGeometry. Path myPath = new Path(); myPath.Stroke = Brushes.Black; myPath.StrokeThickness = 1; myPath.Data = myPathGeometry;

 

3。比较常用的一种方法，用于绘制连续的线段：StreamGeometry 。它与 PathGeometry 类类似，StreamGeometry 定义一个可以包含曲线、弧线和直线的复杂几何形状。与 PathGeometry 不同，StreamGeometry 的内容不支持数据绑定、动画或修改。当您需要描绘复杂的几何图形，但不希望因为支持数据绑定、动画或修改而引入系统开销时，可使用 StreamGeometry。由于它的高效，StreamGeometry 类是描绘装饰物的理想选择。

实例代码如下：

public StreamGeometryTriangleExample() { // Create a path to draw a geometry with. Path myPath = new Path(); myPath.Stroke = Brushes.Black; myPath.StrokeThickness = 1; // Create a StreamGeometry to use to specify myPath. StreamGeometry geometry = new StreamGeometry(); geometry.FillRule = FillRule.EvenOdd; // Open a StreamGeometryContext that can be used to describe this StreamGeometry // object's contents. using (StreamGeometryContext ctx = geometry.Open()) { // Begin the triangle at the point specified. Notice that the shape is set to // be closed so only two lines need to be specified below to make the triangle. ctx.BeginFigure(new Point(10, 100), true /* is filled */, true /* is closed */); // Draw a line to the next specified point. ctx.LineTo(new Point(100, 100), true /* is stroked */, false /* is smooth join */); // Draw another line to the next specified point. ctx.LineTo(new Point(100, 50), true /* is stroked */, false /* is smooth join */); } // Freeze the geometry (make it unmodifiable) // for additional performance benefits. geometry.Freeze(); // Specify the shape (triangle) of the Path using the StreamGeometry. myPath.Data = geometry; // Add path shape to the UI. StackPanel mainPanel = new StackPanel(); mainPanel.Children.Add(myPath); this.Content = mainPanel; }

 

好了方法说完了。以下是我做的一个练习，效果如图。

 

 

代码如下：

using System; using System.Collections.Generic; using System.Text; using System.Windows; using System.Windows.Controls; using System.Windows.Data; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Imaging; using System.Windows.Shapes; namespace WPFDrawingTraning { /// <summary> /// Interaction logic for DrawLine.xaml /// </summary> public partial class DrawLine : System.Windows.Window { //StackPanel mainPanel = new StackPanel(); Canvas mainPanel = new Canvas(); public DrawLine() { InitializeComponent(); // Add path shape to the UI. this.Content = mainPanel; Drawpentagon(); } /// <summary> /// 绘制一组线段 /// </summary> protected void Drawing() { PathFigure myPathFigure = new PathFigure(); myPathFigure.StartPoint = new Point(10, 50); LineSegment myLineSegment = new LineSegment(); myLineSegment.Point = new Point(200, 70); PathSegmentCollection myPathSegmentCollection = new PathSegmentCollection(); myPathSegmentCollection.Add(myLineSegment); myPathFigure.Segments = myPathSegmentCollection; PathFigureCollection myPathFigureCollection = new PathFigureCollection(); myPathFigureCollection.Add(myPathFigure); PathGeometry myPathGeometry = new PathGeometry(); myPathGeometry.Figures = myPathFigureCollection; Path myPath = new Path(); myPath.Stroke = Brushes.Black; myPath.StrokeThickness = 1; myPath.Data = myPathGeometry; // Add path shape to the UI. StackPanel mainPanel = new StackPanel(); mainPanel.Children.Add(myPath); this.Content = mainPanel; } /// <summary> /// 绘制线段 /// </summary> protected void DrawingLine(Point startPt,Point endPt) { LineGeometry myLineGeometry = new LineGeometry(); myLineGeometry.StartPoint = startPt; myLineGeometry.EndPoint = endPt; Path myPath = new Path(); myPath.Stroke = Brushes.Black; myPath.StrokeThickness = 1; myPath.Data = myLineGeometry; mainPanel.Children.Add(myPath); } /// <summary> /// 绘制星状线 /// </summary> protected void DrawingAstroid(Point center,double r) { double h1 = r * Math.Sin(18 * Math.PI / 180); double h2 = r * Math.Cos(18*Math.PI/180); double h3 = r * Math.Sin(36 * Math.PI / 180); double h4 = r * Math.Cos(36 * Math.PI / 180); ; Point p1 = new Point(r, 0); Point p2 = new Point(r - h2, r - h1); Point p3 = new Point(r - h3, r + h4); Point p4 = new Point(r + h3, p3.Y); Point p5 = new Point(r + h2, p2.Y); Point[] values = new Point[] { p1, p2, p3, p4, p5 }; PathFigureCollection myPathFigureCollection = new PathFigureCollection(); PathGeometry myPathGeometry = new PathGeometry(); for (int i = 0; i < values.Length; i++) { //DrawingLine(center, values[i]); PathFigure myPathFigure = new PathFigure(); myPathFigure.StartPoint = center; LineSegment myLineSegment = new LineSegment(); myLineSegment.Point = values[i]; PathSegmentCollection myPathSegmentCollection = new PathSegmentCollection(); myPathSegmentCollection.Add(myLineSegment); myPathFigure.Segments = myPathSegmentCollection; myPathFigureCollection.Add(myPathFigure); } myPathGeometry.Figures = myPathFigureCollection; Path myPath = new Path(); myPath.Stroke = Brushes.Black; myPath.StrokeThickness = 1; myPath.Data = myPathGeometry; mainPanel.Children.Add(myPath); } /// <summary> /// 绘制五角星 /// </summary> private void Drawpentagon() { Point center = new Point(50, 50); double r = 50; DrawingAstroid(center, r); double h1 = r * Math.Sin(18 * Math.PI / 180); double h2 = r * Math.Cos(18 * Math.PI / 180); double h3 = r * Math.Sin(36 * Math.PI / 180); double h4 = r * Math.Cos(36 * Math.PI / 180); ; Point p1 = new Point(r, 0); Point p2 = new Point(r - h2, r - h1); Point p3 = new Point(r - h3, r + h4); Point p4 = new Point(r + h3, p3.Y); Point p5 = new Point(r + h2, p2.Y); Point[] values = new Point[] { p1, p3, p5, p2, p4 }; // Create a path to draw a geometry with. Path myPath = new Path(); myPath.Stroke = Brushes.Black; myPath.StrokeThickness = 1; StreamGeometry theGeometry = BuildRegularPolygon(values, true, false); // Create a StreamGeometry to use to specify myPath. theGeometry.FillRule = FillRule.EvenOdd; // Freeze the geometry (make it unmodifiable) // for additional performance benefits. theGeometry.Freeze(); // Use the StreamGeometry returned by the BuildRegularPolygon to // specify the shape of the path. myPath.Data = theGeometry; // Add path shape to the UI. mainPanel.Children.Add(myPath); } /// <summary> /// 绘制连续的线段 /// </summary> /// <param name="values"></param> /// <returns></returns> private StreamGeometry BuildRegularPolygon(Point[] values, bool isClosed,bool isfilled) { // c is the center, r is the radius, // numSides the number of sides, offsetDegree the offset in Degrees. // Do not add the last point. StreamGeometry geometry = new StreamGeometry(); using (StreamGeometryContext ctx = geometry.Open()) { ctx.BeginFigure(values[0], isfilled /* is filled */, isClosed /* is closed */); for (int i = 1; i < values.Length; i++) { ctx.LineTo(values[i], true /* is stroked */, false /* is smooth join */); } } return geometry; } } }