获取使用LINQ绑定折线集合的topleft和bottomright点

Question

所以我有一系列折线，每个折线都包含几个点。

我想从这些折线集合中获取最小和最大X，Y点，以便我可以找出包含折线的边界矩形。我如何使用LINQ做到这一点？

折线是Canvas的子项。在附图中，绘制了三条红色折线。黄色矩形是虚构的边界。

var polylines = this.CanvasDraw.Children.Cast<Polyline>();

我想做点什么

        double minX;
        double minY;
        double maxX;
        double maxY;

        foreach (Polyline polyline in polylines)
        {
            foreach (var point in polyline.Points)
            {
                if (point.X is the minimum)
                {
                    minX = point.X;
                }

                 if (point.Y is the minimum)
                {
                    minY = point.Y;
                }

                if (point.X is the maximum)
                {
                    maxX = point.X;
                }

                if (point.Y is the maximum)
                {
                    maxY = point.Y;
                }
            }
        }

Point Topleft = new Point(minX, minY);
Point BottomRight = new Point(maxX, maxY);

Answer 1

您可以使用SelectMany将所有行中的点数转换为单个集合，然后使用Min()和Max()来消除极端情况：

var polylines = this.CanvasDraw.Children.Cast<Polyline>();

// project all points into a single list
var allPoints = polylines.SelectMany(pl=>pl.Points).ToList();

// get mins and maxes
var minX = allPoints.Min(p=>p.X);
var minY = allPoints.Min(p=>p.Y);
var maxX = allPoints.Max(p=>p.X);
var maxY = allPoints.Max(p=>p.Y);

// create bounding points
Point Topleft = new Point(minX, minY);
Point BottomRight = new Point(maxX, maxY);