SchemaNameCollection.IList.IndexOf Method (Object)
Determines the index of a specified item in the list.
Assembly: System.DirectoryServices (in System.DirectoryServices.dll)
Starting with the .NET Framework 2.0, this method uses the Equals and CompareTo methods of the objects in the collection to determine whether item exists. In the earlier versions of the .NET Framework, this determination was made by using the Equals and CompareTo methods of the item parameter on the objects in the collection.
Available since 1.1