Question

情况如下：我有一个UIElement，每个角落有4个椭圆我想能够用鼠标/触摸拖动这些并使元素调整大小

（就像在添加形状时在Word中一样，...）

这是我目前的代码：

private void ResizeElement_PointerPressed(object sender, PointerRoutedEventArgs e) {
   var fe = AssociatedObject as FrameworkElement;
   ElementStartResizing?.Invoke(fe, new EventArgs());

   ResizeEllipse = (Ellipse) sender;

   ResizeEllipse.ManipulationMode = ManipulationModes.TranslateX | ManipulationModes.TranslateY;
   ResizeEllipse.ManipulationDelta += ResizeElement_PointerMoved;
   ResizeEllipse.PointerReleased += ResizeElement_PointerReleased;

   pointerId = (int) e.Pointer.PointerId;
   prevPoint = e.GetCurrentPoint(parent).Position;

   switch (ResizeEllipse.Name) {
      case "TopLeft":
         centerPoint = new Point(fe.RenderSize.Width, fe.RenderSize.Height);
         break;
      case "TopRight":
         centerPoint = new Point(0, fe.RenderSize.Height);
         break;
      case "BottomLeft":
         centerPoint = new Point(fe.RenderSize.Width, 0);
         break;
      case "BottomRight":
         centerPoint = new Point(0, 0);
         break;
   }
}

private void ResizeElement_PointerMoved(object sender, ManipulationDeltaRoutedEventArgs args) {
   var fe = AssociatedObject as FrameworkElement;
   var pos = args.Delta.Translation;

   ResizeElement(centerPoint.X, centerPoint.Y, pos.X, pos.Y);

   ElementResizing?.Invoke(fe, new EventArgs());
}

private void ResizeElement (double centerX, double centerY, double scaleX, double scaleY) {
   var item = AssociatedObject as FrameworkElement;
   var visual = ElementCompositionPreview.GetElementVisual(item);
   var _compositor = ElementCompositionPreview.GetElementVisual(item).Compositor;

   visual.CenterPoint = new Vector3((float) centerX, (float) centerY, 0);

   var scaleOut = _compositor.CreateVector2KeyFrameAnimation();
   scaleOut.InsertKeyFrame(0f, new Vector2(visual.Size.X + (float) scaleX, visual.Size.Y + (float) scaleY));

   visual.StartAnimation("Size", scaleOut);
}

问题在于构图动画＆＃34;尺寸＆＃34;出于某种原因根本不起作用。（在我的所有项目上，只有＆＃34; Scale＆＃34;＆＃34; Opacity＆＃34;工作）

修改

其他信息：这是一个类，而不是Control（没有Xaml）

public class ResizeBehavior : DependencyObject, IBehavior {

   public DependencyObject AssociatedObject { get; set; }

   public void Attach (DependencyObject associatedObject) {
      if ((associatedObject != AssociatedObject) && !Windows.ApplicationModel.DesignMode.DesignModeEnabled) {
         AssociatedObject = associatedObject;
         if (AssociatedObject is FrameworkElement fe) {
            fe.Loaded += Fe_Loaded;
         }
      }
   }

   [...]
}

Answer 1

它可能不是最优雅的方式，但我通过结合ManipulationDelta和改变高度和宽度找到了一个解决方案：

private void ResizeElement (double scaleX, double scaleY) {
   var fe = AssociatedObject as FrameworkElement;
   fe.Width = fe.ActualWidth + scaleX;
   fe.Height = fe.ActualHeight + scaleY;
}

我删除了组合API方法并使用了普通的方法

UWP使用鼠标拖动调整UIElement

1 个答案: