C # wavy line drawing

Wavy line above effects

Interface drawing operation

 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         else
10         {
11             //删除预览
12             if (_previewLineElement != null )
 13 is              {
 14                  ContainerCanvas.Children.Remove (_previewLineElement);
 15                  _previewLineElement = null ;
 16                  _lastMovedPoint = null ;
 . 17              }
 18 is              // determine the end point, the wavy line drawn 
. 19              var myLineElement = new new MyLineElement ();
 20 is              myLineElement.DrawLine ( (Point) _startPoint, position);
 21 is              ContainerCanvas.Children.Add (myLineElement);
 22 is              _startPoint = null ;
 23 is         }
24     }
25 
26     private MyLineElement _previewLineElement = null;
27     private Point? _lastMovedPoint = null;
28 
29     /// <summary>
30     /// 波浪线绘制预览
31     /// </summary>
32     /// <param name="sender"></param>
33     /// <param name="e"></param>
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     }

Controls and wavy lines drawn

  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<Point> points = ForgePoints(startPoint, endPoint);
 10             DrawLine(points);
 11         }
 12         private const int SeparatorPiexl = 4;
 13         private const int AbundancePiexl = 3;
 14         private List<Point> ForgePoints(Point startPoint, Point endPoint)
 15         {
 16             var points = new List<Point>();
 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 is              int index = 0 ;
 24              BOOL isAbundanceUpward = to true ;
 25              the while (index * SeparatorPiexl < lineDistance)
 26 is              {
 27                  index ++ ;
 28                  // calculate the interval length (analog point to the starting point) 
29                  var separatorDistance = index * SeparatorPiexl;
 30                  var = abundancePiexl abundancePiexl;
 31 is                  var distanceToStartPoint = Math.Sqrt (Math.Pow (separatorDistance, 2 ) + Math.Pow (abundancePiexl, 2 ));
 32                 // calculate the simulated points, start point, an angle with the straight line 
33 is                  var separatorAngle = Math.atan2 (AbundancePiexl, separatorDistance);
 34 is                  separatorAngle = isAbundanceUpward separatorAngle:? - separatorAngle;
 35                  isAbundanceUpward =! IsAbundanceUpward;
 36                  // obtain an analog point the horizontal angle of 
37 [                  var mockPointAngle + = lineAngle separatorAngle;
 38 is                  // calculated coordinates analog 
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<Point> points)
 49         {
 50             _visualShape.Clear();
 51 
 52             var geometryTest = new StreamGeometry();
 53             the using ( var CTX = geometryTest.Open ())
 54 is              {
 55                  ctx.BeginFigure (Points [ 0 ], to true , to false );
 56 is                  IF (points.Count% 2 == 0 )
 57 is                  {
 58                      // Draw second order Bessel Seoul function, the need to ensure an even point 
59                      ctx.PolyQuadraticBezierTo (points, to true , to true );
 60                  }
 61 is                  the else 
62 is                  {
 63 is                      //Draw second order Bessel functions, the need to ensure an even point 
64                      points.Insert ( 0 , Points [ 0 ]);
 65                      ctx.PolyQuadraticBezierTo (Points, to true , to true );
 66                  }
 67  
68                  ctx.Close ();
 69              }
 70  
71 is              var Visual = new new the DrawingVisual ();
 72              the using ( var context = visual.RenderOpen ())
 73 is              {
 74                 context.DrawGeometry (FillBrush, StrokePen, geometryTest);
 75              }
 76              _visualShape.Add (Visual);
 77          }
 78  
79          #region internal method
 80  
81          [The Obsolete]
 82          protected  the override  void the OnRender (a DrawingContext DrawingContext)
 83          {
 84              // deprecated , to achieve filling _visualShape
 85              // drawingContext.DrawGeometry (FillBrush, StrokePen, BaseGeometry); 
86          }
 87  
88          protected  the 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         #endregion
101 
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 StrokePen
110         {
111             get
112             {
113                 if (_defaultPen == null)
114                 {
115                     _defaultPen = new Pen(LineBrush, BorderThickness);
116                 }
117                 return _defaultPen;
118             }
119             set => _defaultPen = value;
120         }
121 
122         #endregion
123     }

 

Github Address: https://github.com/Kybs0/WaveLineTextDemo