from the creators of DotNetTipOfTheDay.org or

How to determine whether a property or a method is more appropriate for your needs

Use a method when:

The operation is a conversion, such as Object.ToString.
The operation is expensive enough that you want to communicate to the user that they should consider caching the result.
Obtaining a property value using the get accessor would have an observable side effect.
Calling the member twice in succession produces different results.
The order of execution is important. Note that a type's properties should be able to be set and retrieved in any order.
The member returns an array. Properties that return arrays can be very misleading. Usually it is necessary to return a copy of the internal array so that the user cannot change internal state. This, coupled with the fact that a user can easily assume it is an indexed property, leads to inefficient code.

P.S. this is not a comprehensive list of guidelines. See Design Guidelines for Class Library Developers for more.

10/18/2007