使用鼠标UWP调整UI元素的大小

Question

我可以使用Pinch to zoom缩放比例，但也需要使用鼠标Pinch to zoom 。 我如何实现它，因为我也可以拖动图像。

这是我用手指缩放的代码

  private void Image_ManipulationDelta(object sender, ManipulationDeltaRoutedEventArgs e)
  {
      var ct = (CompositeTransform)image.RenderTransform;
      ct.ScaleX *= e.Delta.Scale;
      ct.ScaleY *= e.Delta.Scale;
  }

Answer 1

我可以使用Pinch缩放缩放比例，但也需要使用鼠标进行缩放。

您可以使用UIElement.PointerWheelChanged事件来更改比例：

代码隐藏：

private void Image_PointerWheelChanged(object sender, PointerRoutedEventArgs e)
{
    int delta=e.GetCurrentPoint((UIElement)sender).Properties.MouseWheelDelta;
    var ct = (CompositeTransform)img.RenderTransform;
    ct.ScaleX += delta / 120;//you can set 120 to other value to change the sensitivity
    ct.ScaleY += delta / 120;
}

Xaml：

<Canvas Width="800" Height="800">
    <Image Name="img" Source="ms-appx:///Assets/profiler.jpeg" PointerWheelChanged="Image_PointerWheelChanged"></Image>
</Canvas>

Answer 2

它不是最终结果，调整大小后需要释放鼠标按钮

private void Image_ManipulationDelta(object sender, ManipulationDeltaRoutedEventArgs e)
    {
        var border = sender as Border;  
            if (mousePos.X> pos.X|| mousePos.Y > pos.Y)
            {
                ct.ScaleX += e.Delta.Translation.X;
                ct.ScaleY += e.Delta.Translation.Y;
            }
            if (mousePos.X < pos.X || mousePos.Y < pos.Y)
            {
                ct.ScaleX += e.Delta.Translation.X;
                ct.ScaleY += e.Delta.Translation.Y;
            }
    }
  private void ImageBorder_PointerPressed(object sender, PointerRoutedEventArgs e)
    {
        pos = Window.Current.CoreWindow.PointerPosition;
    }

    private void ImageBorder_PointerReleased(object sender, PointerRoutedEventArgs e)
    {
        pos = Window.Current.CoreWindow.PointerPosition;
    }