ListBox.ObjectCollection.Insert Method (Int32, Object)
Inserts an item into the list box at the specified index.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
This method enables you to insert an item at a specific position within the ListBox. If the Sorted property of the ListBox is set to true, the item is added in the correct position within the sorted list regardless of the values specified in the index parameter. When an object is added to the collection, the ListBox first checks to see if the DisplayMember property of the ListControl class has the name of a member from the object specified to reference when obtaining the item text. If the DisplayMember property does not have a member specified, the ListBox then calls the ToString method of the object to obtain the text to display in the list.
Available since 1.1