Occurs when the input system reports an underlying drag event with this element as the potential drop target.
public event System.Windows.DragEventHandler PreviewDragOver;
This event creates an alias for the <xref:System.Windows.DragDrop.PreviewDragOver?displayProperty=nameWithType> attached event for this class, so that PreviewDragOver is part of the class members list when UIElement is inherited as a base element. Event handlers that are attached to the PreviewDragOver event are attached to the underlying <xref:System.Windows.DragDrop.PreviewDragOver?displayProperty=nameWithType> attached event and receive the same event data instance.
Routed Event Information
The corresponding bubbling event is DragOver.
Override OnPreviewDragOver to implement class handling for this event in derived classes.