将绘制的矩形对齐

Question

我有一个WPF应用程序，其中我在画布中绘制矩形。我需要添加一个功能，当我绘制一个矩形时，如果旁边有一个矩形（例如：假设第一个矩形x坐标是236和第二个矩形坐标是235）我需要将第二个矩形x坐标捕捉到236，如图所示。 仅当距离差为10时才会进行捕捉。

我已经编写了以下代码来执行此操作。

private void Canvas_MouseDown(object sender, MouseButtonEventArgs e)
        {                        
          startPos = e.GetPosition(Canvas);
           System.Windows.Point curPosition = e.GetPosition(SectionCanvas);
           rect = new System.Windows.Shapes.Rectangle
           {
               Stroke = brushColor,
               StrokeDashArray = new DoubleCollection { 2, 2 },
               Tag = "rectangle"
           };     
        Canvas.SetLeft(rect, startPos.X);
                Canvas.SetTop(rect, startPos.X);
                SectionCanvas.Children.Add(rect);
         }

 private void Canvas_MouseMove(object sender, MouseEventArgs e)
        {

                currentPos = e.GetPosition(SectionCanvas);

                var x = Math.Min(currentPos.X, startPos.X);
                var y = Math.Min(currentPos.Y, startPos.Y);

                var w = Math.Max(currentPos.X, startPos.X) - x;
                var h = Math.Max(currentPos.Y, startPos.Y) - y;

                rect.Width = w;
                rect.Height = h;

                Canvas.SetLeft(rect, x);
                Canvas.SetTop(rect, y);

        }

   private void Canvas_MouseUp(object sender, MouseButtonEventArgs e)
        {                                   
              if(rect == null)
              {
                  MessageBox.Show("Could not capture section, Please try again");
                  return;
              }
              endPos = e.GetPosition(SectionCanvas);
              IEnumerable<Rect> coordinates = rectCollection.Select(r => new Rect(Canvas.GetLeft(r), Canvas.GetTop(r), r.Width, r.Height));
              Rect newCordinates = new Rect(Canvas.GetLeft(rect), Canvas.GetTop(rect), rect.Width, rect.Height);                   
              if (coordinates.Any(c => c.IntersectsWith(newCordinates)))))
              {
                  MessageBox.Show("New Rectangle intersects with existing rectangle");
                  Canvas.Children.Remove(rect);
                  return;
              }
              rectCollection.Add(rect);
              rect = null;    

              foreach(Point p in tempCollection)
                    {
                        if((startPos.X <= (p.X + 10) && startPos.X >= (p.X -10)))
                        {
                            startPos.X = p.X;
                        }
                        if(endPos.X <= (p.X + 10) && endPos.X >= (p.X - 10))
                        {
                            var x1 = Math.Max(endPos.X,p.X) - Math.Min(endPos.X, p.X);
                            var w1 = startPos.X - x1;
                            endPos.X = p.X;
                            startPos.X = w1;
                        }
                        if ((startPos.Y <= (p.Y + 10) && startPos.Y >= (p.Y - 10)))
                        {
                            startPos.Y = p.Y;
                        }

                        if (endPos.Y <= (p.Y + 10) && endPos.Y >= (p.Y - 10))
                        {
                            var x1 = Math.Max(endPos.Y, p.Y) - Math.Min(endPos.Y, p.Y);
                            var w1 = startPos.Y - x1;
                            endPos.Y = p.Y;
                        }
                    }
                    var x = Math.Min(currentPos.X, startPos.X);
                    var y = Math.Min(currentPos.Y, startPos.Y);

                    var w = Math.Max(currentPos.X, startPos.X) - x;
                    var h = Math.Max(currentPos.Y, startPos.Y) - y;

                    rect.Width = w;
                    rect.Height = h;

                    rect.Stroke = Brushes.Coral;

                    Canvas.SetLeft(rect, x);
                    Canvas.SetTop(rect, y);
                    rect = null;
                    tempCollection.Add(startPos);
                    tempCollection.Add(endPos);
            }

当我更改端点值时，上面的代码不起作用。在调试时，我可以看到终点值发生变化，但绘制的矩形不会改变。我无法找出我做错了什么。

Answer 1

我想出了答案，这是我最后的一个愚蠢的错误。

在计算捕捉后的宽度和高度时，我使用的是currentPos，而不是使用endPos。

 var x = Math.Min(endPos.X, startPos.X);
 var y = Math.Min(endPos.Y, startPos.Y);

 var w = Math.Max(endPos.X, startPos.X) - x;
 var h = Math.Max(endPos.Y, startPos.Y) - y;