WPF inkcanvas選中筆跡縮放、旋轉，放大縮小畫布、移動畫布 獲取縮放、旋轉后的寬高

源碼_gitee
源碼_github
使用裝飾層實現

支持蟻行線
可以直接用inkcanvas的GestureOnly模式實現

預覽繪制形狀

使用說明
按住ctrl+鼠標滾輪縮放畫布
按住空格+按住鼠標左鍵+移動鼠標位置拖動畫布(需要放大才能使用)

不使用inkcanvas的select即可屏蔽默認的裝飾層

在MoveRotateAdorner類中的OnRender繪制裝飾層

預覽的邏輯是添加一個裝飾層繪制預覽效果,在mouseup事件進行最后實際效果的繪制

注意重繪的代碼將自身傳入,以獲取相關屬性,同時保證引用不發生變化
與控制相關的部分代碼

      private void Rotate(double angle)
        {
            if (selectionStrokes.Count == 0)
            {
                return;
            }
            //var bound = selectionStrokes.GetBounds();

            Matrix matrix = new Matrix();
            matrix.RotateAt(angle, bound.Left + bound.Width / 2, bound.Top + bound.Height / 2);
            selectionStrokes.Transform(matrix, false);


            bound = selectionStrokes.GetBounds();

        }

        //double lastScaleX = 1;
        //double lastScaleY = 1;
        /// <summary>
        /// 縮放
        /// </summary>
        /// <param name="scaleX">縮放比例</param>
        /// <param name="scaleY">縮放比例</param>
        /// <param name="middleX">縮放中心點</param>
        /// <param name="middleY">縮放中心點</param>
        private void ReSize(double scaleX, double scaleY, double middleX, double middleY)
        {
            if ((selectionStrokes?.Count ?? 0) == 0)
            {
                return;
            }

            Matrix matrix = new Matrix();

            matrix.ScaleAt(scaleX, scaleY, middleX, middleY);

            Trace.WriteLine($"scale x:{ scaleX}, scale y:{ scaleY}");
            selectionStrokes.Transform(matrix, false);
            scaleRound = selectionStrokes.GetBounds();

            bound = selectionStrokes.GetBounds();
            ReDraw(this);
        }
        public void Move(double x, double y)
        {
            if ((selectionStrokes?.Count ?? 0) == 0)
            {
                return;
            }

            Matrix matrix = new Matrix();

            matrix.OffsetX = x;
            matrix.OffsetY = y;

            selectionStrokes.Transform(matrix, false);
            scaleRound = selectionStrokes.GetBounds();

            bound = selectionStrokes.GetBounds();
            ReDraw(this);
        }

        public void ReDraw(MoveRotateAdorner adorner = null)
        {
            ClearAdorner();
            ReDrawAdorner(adorner);
        }

        public void ClearAdorner()
        {
            var layer = AdornerLayer.GetAdornerLayer(adornedElement);
            var arr = layer.GetAdorners(adornedElement);//獲取該控件上所有裝飾器，返回一個數組

            if (arr != null)
            {
                for (int i = arr.Length - 1; i >= 0; i--)
                {
                    layer.Remove(arr[i]);
                }
            }
        }
        public MoveRotateAdorner ReDrawAdorner(MoveRotateAdorner adorner = null)
        {
            var layer = AdornerLayer.GetAdornerLayer(adornedElement);

            adorner = adorner ?? new MoveRotateAdorner(adornedElement, selectionStrokes);
            layer.Add(adorner);
            return adorner;
        }

選擇筆跡

//在畫布位置處理點擊事件
//mouse up
//選中筆跡
 foreach (var item in writeBorad.Strokes)
{
  var result = item.HitTest(paths, 1);
  Trace.WriteLine(result);
  if (result)
  {
    selectionStrokes.Add(item);
  }
}
adorner = new MoveRotateAdorner(writeBorad, selectionStrokes);
if (selectionStrokes.Count == 0)
{
  adorner?.ClearAdorner();
}
else
{
  adorner?.ReDraw();
}

獲取旋轉后的寬高

 var bounds = borderTest.TransformToAncestor((Visual)borderTest.Parent)
                  .TransformBounds(new Rect(borderTest.RenderSize));
            Debug.WriteLine($"x:{bounds.X}-y:{bounds.Y},width:{bounds.Width},height:{bounds.Height}");

非標准形狀可通過path進行繪制，通過設置 Stretch="Fill" 進行縮放
inkcanvas內部元素也可被選中，通過設置縮放即可實現調整大小