C#开发PACS医学影像处理系统(十三)：绘图处理之病灶测量
接上一篇文章，当我们可以绘制图形标记后，就可以在此操作类上面进行扩展，
比如测量类工具，目前整理出的常用绘图和测量功能如下：
测量工具类：（图形标记类请参考本系列文章：绘图处理之图形标记）
| 功能 | 说明 |
| 标尺 | 线段长度测量 |
| 折尺 | 曲线长度测量 |
| 心胸比 | 两根线段按比例测量 |
| 交叉尺 | 两根线段互相垂直测量 |
| Cobb角 | 两根线段的垂线交点角度测量，一般用于脊柱曲率 |
| 开角 | 两根线段的延长交点的角度测量 |
| T型尺 | 两根线段相交的任意角度摇摆测量和长度测量 |
| 角度测量 | 角度测量 |
| 圆形测量 | 圆形或椭圆面积测量，包括CT值，平均值，方差，最大最小值 |
| 矩形测量 | 矩形面积测量，包括CT值，平均值，方差，最大最小值 |
| 多边形测量 | 多边形面积 |
以线段测量为例，看效果：
在绘制图形的基础上，我们创建一个Text Block来显示测量结果：
//文本对象 TextBlock txtMeasure; /// <summary> /// 创建测量结果文本 /// </summary> /// <param name="point"></param> public void CreateMeasure(Point point) { if (!isMeasure) { return; } txtMeasure = new TextBlock(); txtMeasure.Text = "0.0mm"; txtMeasure.FontSize = ShapeManager.shapeMeasureFontSize; txtMeasure.Foreground = ShapeManager.shapeMeasureColor; txtMeasure.Height = 30; txtMeasure.Width = 100; txtMeasure.SetValue(Canvas.LeftProperty, point.X); txtMeasure.SetValue(Canvas.TopProperty, point.Y); canvas.Children.Add(txtMeasure); measureList.Add(txtMeasure); }
计算两点之间的距离：其中dpi是缩放比例
/// <summary> /// 求平面中两点之间距离 /// </summary> /// <param name="p1">点1</param> /// <param name="p2">点2</param> /// <returns></returns> public static double GetDistance(Point p1, Point p2) { double result = 0; result = Math.Sqrt((p1.X * dpiX - p2.X * dpiX) * (p1.X * dpiX - p2.X * dpiX) + (p1.Y * dpiY - p2.Y * dpiY) * (p1.Y * dpiY - p2.Y * dpiY)); return result; }
一些角度类型的测量计算相对复杂一点，需要计算角度大小和绘制弧线
/// <summary> /// 弧线画笔对象 /// </summary> public Stroke circleStroke; /// <summary> /// 绘制角度弧线 /// </summary> private void DrawAxiesCircle(Point point0, Point point1, Point point2) { if (inkCanvas.Strokes.Count > 0 && circleStroke != null) { if (inkCanvas.Strokes.Contains(circleStroke)) { inkCanvas.Strokes.Remove(circleStroke); } } //计算角度 double a = Math.Sqrt((point1.X - point2.X) * (point1.X - point2.X) + (point1.Y - point2.Y) * (point1.Y - point2.Y)); double b = Math.Sqrt((point1.X - point0.X) * (point1.X - point0.X) + (point1.Y - point0.Y) * (point1.Y - point0.Y)); double c = Math.Sqrt((point2.X - point0.X) * (point2.X - point0.X) + (point2.Y - point0.Y) * (point2.Y - point0.Y)); double cTheta = (a * a + b * b - c * c) / (2 * a * b); double theta = Math.Acos(cTheta) * 180 / Math.PI; //绘制弧线 double r = 30; r = a > b ? b : a; double rMax = a; if (rMax > b) { rMax = b; } if (r > 0.5 * rMax) { r = 0.5 * rMax; } double theta0 = Math.Atan((point1.Y - point2.Y) / (point2.X - point1.X + 1e-10)) * 180 / Math.PI; if (point1.X > point2.X) { theta0 = 180 + theta0; } List<Point> pointList = new List<Point>(); double sin_ab = ((point2.X - point1.X) * (point0.Y - point1.Y) - (point2.Y - point1.Y) * (point0.X - point1.X)) / (a * b); ; if (sin_ab <= 0) { if (theta < 1) { for (double delta = 0.0001; delta <= theta;) { double th = delta + theta0; pointList.Add(new Point(point1.X + r * Math.Cos(th * Math.PI / 180), point1.Y - r * Math.Sin(th * Math.PI / 180))); delta = delta + 0.0001; } } else if (theta > 1 && theta < 20) { for (double delta = 0.01; delta <= theta;) { double th = delta + theta0; pointList.Add(new Point(point1.X + r * Math.Cos(th * Math.PI / 180), point1.Y - r * Math.Sin(th * Math.PI / 180))); delta = delta + 0.01; } } else { for (double delta = 0; delta <= theta; delta++) { double th = delta + theta0; pointList.Add(new Point(point1.X + r * Math.Cos(th * Math.PI / 180), point1.Y - r * Math.Sin(th * Math.PI / 180))); } } } else { if (theta < 1) { for (double delta = -theta; delta <= 0;) { double th = delta + theta0; pointList.Add(new Point(point1.X + r * Math.Cos(th * Math.PI / 180), point1.Y - r * Math.Sin(th * Math.PI / 180))); delta = delta + 0.0001; } } else if (theta > 1 && theta < 20) { for (double delta = -theta; delta <= 0;) { double th = delta + theta0; pointList.Add(new Point(point1.X + r * Math.Cos(th * Math.PI / 180), point1.Y - r * Math.Sin(th * Math.PI / 180))); delta = delta + 0.01; } } else { for (double delta = -theta; delta <= 0; delta++) { double th = delta + theta0; pointList.Add(new Point(point1.X + r * Math.Cos(th * Math.PI / 180), point1.Y - r * Math.Sin(th * Math.PI / 180))); } } } if (pointList.Count > 0) { StylusPointCollection point = new StylusPointCollection(pointList); circleStroke = new Stroke(point) { DrawingAttributes = inkCanvas.DefaultDrawingAttributes.Clone(), }; inkCanvas.Strokes.Add(circleStroke); txt.Text = theta.ToString(ShapeManager.measureDigit) + "°"; } ReSetAnglePoint(); }
在圆形和矩形的面积测量中，我们可以使用GetArea()方法来获取图形面积：
/// <summary> /// 计算面积测量结果 /// </summary> public void CalculateMeasure() { if (!isMeasure) { return; } Ellipse ellipse = (Ellipse)shape; ellipse.UpdateLayout(); txtMeasure.Text = Math.Sqrt(ellipse.RenderedGeometry.GetArea()).ToString(ShapeManager.measureDigit) + "mm²"; ReSetMeasurePoint(); }
其他一些需要注意的细节：
1.当单元格放大缩小时，图形也要重新计算各个控制点的位置来同步放大或缩小
监听画布大小变化事件：
private void ToolInkCanvas_SizeChanged(object sender, SizeChangedEventArgs e)
重新绘制元素：
/// <summary> /// 重新绘制画布元素大小 /// </summary> public void ReSetShapeSize() { for (int i = 0; i < shapeManager.shapeList.Count; i++) { sizeScaleX = ToolInkCanvas.ActualWidth / shapeManager.shapeList[i].cvsWidth; sizeScaleY = ToolInkCanvas.ActualHeight / shapeManager.shapeList[i].cvsHeight; shapeManager.shapeList[i].cvsWidth = ToolInkCanvas.ActualWidth; shapeManager.shapeList[i].cvsHeight = ToolInkCanvas.ActualHeight; if (shapeManager.shapeList[i] is TextInfo) { shapeManager.shapeList[i].ReSetScalePoints(sizeScaleX, sizeScaleY, "text", shapeManager.shapeList[i]); } else if (shapeManager.shapeList[i] is CrossRulerInfo) { shapeManager.shapeList[i].ReSetScalePoints(sizeScaleX, sizeScaleY, "crossRuler", shapeManager.shapeList[i]); } else if (shapeManager.shapeList[i] is AngleRulerInfo) { shapeManager.shapeList[i].ReSetScalePoints(sizeScaleX, sizeScaleY, "angle", shapeManager.shapeList[i]); } else if (shapeManager.shapeList[i] is TRulerInfo) { shapeManager.shapeList[i].ReSetScalePoints(sizeScaleX, sizeScaleY, "tRulerInfo", shapeManager.shapeList[i]); } else if (shapeManager.shapeList[i] is CobbAngleInfo) { shapeManager.shapeList[i].ReSetScalePoints(sizeScaleX, sizeScaleY, "cobbAngleInfo", shapeManager.shapeList[i]); } else if (shapeManager.shapeList[i] is OpenAngleInfo) { shapeManager.shapeList[i].ReSetScalePoints(sizeScaleX, sizeScaleY, "openAngleInfo", shapeManager.shapeList[i]); } else { shapeManager.shapeList[i].ReSetScalePoints(sizeScaleX, sizeScaleY); } } }
2.文字可能会挡住图像，要能分离并拖动到其他位置，监听鼠标事件和重新设置位置即可。
3.标记的复制与粘贴，思路是将List集合中用户所选定的标记插入到另一个单元格的List集合中，并支持Ctrl C和Ctrl V 快捷键。
测量标记汇总（Demo）：
