“Read only” Property Accessor in C#

Question

I have the following class:

class SampleClass
{
   private ArrayList mMyList;

   SampleClass()
   {
       // Initialize mMyList
   }

   public ArrayList MyLis         


        

Answer 1

With an ArrayList you are fairly limited because there is no readonly non-generic collection class in the BCL. The quick and dirty solution is to return a type of IEnumerable.

   public IEnumerable MyList
   {
       get { return mMyList;}
   }

This won't actually prevent someone from casting to ArrayList but it won't allow edits by default either

You can return an effectively readonly list by calling ArrayList.ReadOnly. However it's return type is an ArrayList so the user would still be able to compile with .Add but it would produce a runtime error.