public Nullable<TimeSpan> AddingItemDuration {get; set;}

'Declaration
 
Public Property AddingItemDuration As Nullable(Of TimeSpan)

'Usage
 
Dim instance As ListBoxAnimationSettings
Dim value As Nullable(Of TimeSpan)
 
instance.AddingItemDuration = value
 
value = instance.AddingItemDuration

Property Value

A nullable TimeSpan value representing the duration of the animation when an item is added. By default, null. 

Target Platforms: Windows 11, Windows 10, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

ListBoxAnimationSettings Class
ListBoxAnimationSettings Members