protected void Insert( 
   int index,
   object item
)

Protected Sub Insert( _
   ByVal index As Integer, _
   ByVal item As Object _
) 

Parameters

index

The zero-based index at which item should be inserted.

item

The item being added to the combo box.

All items added to the ItemCollection must be created on the main UI thread as these ultimately become UI content.

Target Platforms: Windows 10, Windows 8.1

Reference

ComboBox Class
ComboBox Members