ArrayList.ReadOnly Method (IList)
Returns a read-only IList wrapper.
Assembly: mscorlib (in mscorlib.dll)
list is a null reference (Nothing in Visual Basic).
To prevent any modifications to list, expose list only through this wrapper.
A collection that is read-only is simply a collection with a wrapper that prevents modifying the collection. If changes are made to the underlying collection, the read-only collection reflects those changes.
This method is an O(1) operation.