波浪线效果如上

界面绘制操作

1     private Point? _startPoint = null; 2     private void ContainerCanvas_OnPreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e) 3     { 4         var position = e.GetPosition(ContainerCanvas); 5         if (_startPoint == null) 6         { 7             _startPoint = position; 8         } 9         else10         {11             //删除预览12             if (_previewLineElement != null)13             {14                 ContainerCanvas.Children.Remove(_previewLineElement);15                 _previewLineElement = null;16                 _lastMovedPoint = null;17             }18             //确定结束点，绘制波浪线19             var myLineElement = new MyLineElement();20             myLineElement.DrawLine((Point)_startPoint, position);21             ContainerCanvas.Children.Add(myLineElement);22             _startPoint = null;23         }24     }25 26     private MyLineElement _previewLineElement = null;27     private Point? _lastMovedPoint = null;28 29     /// 
30     /// 波浪线绘制预览31     /// 
32     /// 33     /// 34     private void ContainerCanvas_OnMouseMove(object sender, MouseEventArgs e)35     {36         var position = e.GetPosition(ContainerCanvas);37         if (_startPoint != null && (_lastMovedPoint == null || _lastMovedPoint != null & (position - (Point)_lastMovedPoint).Length >= 2))38         {39             _lastMovedPoint = position;40             if (_previewLineElement != null)41             {42                 ContainerCanvas.Children.Remove(_previewLineElement);43             }44             var myLineElement = new MyLineElement();45             myLineElement.DrawLine((Point)_startPoint, position);46             ContainerCanvas.Children.Add(myLineElement);47             _previewLineElement = myLineElement;48         }49     }

波浪线控件及绘制

1     class MyLineElement : FrameworkElement  2     {  3         public MyLineElement()  4         {  5             _visualShape = new VisualCollection(this);  6         }  7         internal void DrawLine(Point startPoint, Point endPoint)  8         {  9             List
     
       points = ForgePoints(startPoint, endPoint); 10             DrawLine(points); 11         } 12         private const int SeparatorPiexl = 4; 13         private const int AbundancePiexl = 3; 14         private List
      
        ForgePoints(Point startPoint, Point endPoint) 15         { 16             var points = new List
       
        (); 17  18             var lineVector = endPoint - startPoint; 19             var lineDistance = lineVector.Length; 20             var lineAngle = Math.Atan2(-(endPoint.Y - startPoint.Y), endPoint.X - startPoint.X); 21  22             points.Add(startPoint); 23             int index = 0; 24             bool isAbundanceUpward = true; 25             while (index * SeparatorPiexl < lineDistance) 26             { 27                 index++; 28                 //计算出间隔长度（模拟点到起始点） 29                 var separatorDistance = index * SeparatorPiexl; 30                 var abundancePiexl = AbundancePiexl; 31                 var distanceToStartPoint = Math.Sqrt(Math.Pow(separatorDistance, 2) + Math.Pow(abundancePiexl, 2)); 32                 //计算出模拟点、起始点，与直线的角度 33                 var separatorAngle = Math.Atan2(AbundancePiexl, separatorDistance); 34                 separatorAngle = isAbundanceUpward ? separatorAngle : -separatorAngle; 35                 isAbundanceUpward = !isAbundanceUpward; 36                 //得到模拟点的水平角度 37                 var mockPointAngle = lineAngle + separatorAngle; 38                 //计算出模拟点坐标 39                 var verticalDistance = distanceToStartPoint * Math.Sin(mockPointAngle); 40                 var horizontalDistance = distanceToStartPoint * Math.Cos(mockPointAngle); 41                 var mockPoint = new Point(startPoint.X + horizontalDistance, startPoint.Y - verticalDistance); 42                 points.Add(mockPoint); 43             } 44             points.Add(endPoint); 45             return points; 46         } 47  48         private void DrawLine(List
        
          points) 49         { 50             _visualShape.Clear(); 51  52             var geometryTest = new StreamGeometry(); 53             using (var ctx = geometryTest.Open()) 54             { 55                 ctx.BeginFigure(points[0], true, false); 56                 if (points.Count % 2 == 0) 57                 { 58                     //绘制二阶贝塞尔函数，需要保证为偶数点 59                     ctx.PolyQuadraticBezierTo(points, true, true); 60                 } 61                 else 62                 { 63                     //绘制二阶贝塞尔函数，需要保证为偶数点 64                     points.Insert(0, points[0]); 65                     ctx.PolyQuadraticBezierTo(points, true, true); 66                 } 67  68                 ctx.Close(); 69             } 70  71             var visual = new DrawingVisual(); 72             using (var context = visual.RenderOpen()) 73             { 74                 context.DrawGeometry(FillBrush, StrokePen, geometryTest); 75             } 76             _visualShape.Add(visual); 77         } 78  79         #region 内部方法 80  81         [Obsolete] 82         protected override void OnRender(DrawingContext drawingContext) 83         { 84             //弃用，改为_visualShape填充实现 85             //drawingContext.DrawGeometry(FillBrush, StrokePen, BaseGeometry); 86         } 87  88         protected override int VisualChildrenCount => _visualShape.Count; 89  90         protected override Visual GetVisualChild(int index) 91         { 92             if (index < 0 || index >= _visualShape.Count) 93             { 94                 throw new ArgumentOutOfRangeException(); 95             } 96  97             return _visualShape[index]; 98         } 99 100         #endregion101 102         #region 曲线属性103 104         private readonly VisualCollection _visualShape;105         protected Brush FillBrush { get; set; } = Brushes.Transparent;106         public Brush LineBrush { get; set; } = Brushes.DarkSeaGreen;107         protected double BorderThickness { get; set; } = 1.0;108         private Pen _defaultPen = null;109         protected Pen StrokePen110         {111             get112             {113                 if (_defaultPen == null)114                 {115                     _defaultPen = new Pen(LineBrush, BorderThickness);116                 }117                 return _defaultPen;118             }119             set => _defaultPen = value;120         }121 122         #endregion123     }
        
       
      
     

 

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