EmojiRichTextBoxOnPreviewDragEnter(DragEventArgs) - метод

Handle preview drag event in order to override the serialized data. By default WPF will not serialize embedded elements unless they are images (see [1]), so all our emojis get replaced with " ". To avoid this problem we get rid of the XAML and RTF serialisations and replace the dragged text with the current selection. [1] https://referencesource.microsoft.com/#PresentationFramework/src/Framework/System/windows/Documents/TextRangeSerialization.cs,1180

protected virtual void OnPreviewDragEnter(
	DragEventArgs e
)

Protected Overridable Sub OnPreviewDragEnter ( 
	e As DragEventArgs
)

protected:
virtual void OnPreviewDragEnter(
	DragEventArgs^ e
)

abstract OnPreviewDragEnter : 
        e : DragEventArgs -> unit 
override OnPreviewDragEnter : 
        e : DragEventArgs -> unit