private void OnPreviewMouseWheel(Object sender, MouseWheelEventArgs e)
{
if (!this.CanScaleImage)
{
return;
}
var element = sender as FrameworkElement;
if (element == null)
{
return;
}
// 親Grid取得
var topGrid = element.Parents <Grid>().FirstOrDefault(p => p.Name == "topGrid");
if (topGrid == null)
{
return;
}
// 親Gridが持つ子要素をそれぞれ取得
var thumbnail = VisualTree.Descendants <Image>(topGrid)
.FirstOrDefault(d => d.Name == "thumbnail");
var mainImage = VisualTree.Descendants <Image>(topGrid)
.FirstOrDefault(d => d.Name == "mainImage");
if (thumbnail == null || mainImage == null)
{
return;
}
var scale = 1.0;
// ホイール上に回す→拡大 / 下に回す→縮小
if (e.Delta > 0)
{
scale = 1.25;
}
else
{
scale = 1 / 1.25;
}
// 拡大・縮小実施
var thumbnailMatrix = (thumbnail.RenderTransform as MatrixTransform).Matrix;
thumbnailMatrix.Scale(scale, scale);
thumbnail.RenderTransform = new MatrixTransform(thumbnailMatrix);
var mainImageMatrix = (mainImage.RenderTransform as MatrixTransform).Matrix;
mainImageMatrix.Scale(scale, scale);
mainImage.RenderTransform = new MatrixTransform(mainImageMatrix);
}
private void OnDragDelta(Object sender, DragDeltaEventArgs e)
{
if (!this.CanDragViewport)
{
return;
}
var element = sender as FrameworkElement;
if (element == null)
{
return;
}
// 親Grid取得
var topGrid = element.Parents <Grid>().FirstOrDefault(p => p.Name == "topGrid");
if (topGrid == null)
{
return;
}
// 親Gridが持つ子要素をそれぞれ取得
var scrollViewer = VisualTree.Descendants <ScrollViewer>(topGrid)
.FirstOrDefault(d => d.Name == "mainImageScrollViewer");
var thumbnail = VisualTree.Descendants <Image>(topGrid)
.FirstOrDefault(d => d.Name == "thumbnail");
if (scrollViewer == null || thumbnail == null)
{
return;
}
scrollViewer.ScrollToHorizontalOffset(
scrollViewer.HorizontalOffset + (e.HorizontalChange * scrollViewer.ExtentWidth / thumbnail.ActualWidth));
scrollViewer.ScrollToVerticalOffset(
scrollViewer.VerticalOffset + (e.VerticalChange * scrollViewer.ExtentHeight / thumbnail.ActualHeight));
}
