General Rule for When to Implement IDisposable

Question

EDIT: This question is a duplicate of What is the difference between managed and native resources when disposing? (.NET) and many others. Please answer the

Answer 1

IDisposable is one of a programmers main weapons against .Net memory leaks. Whilst the documentation suggests that it should be used for external resources, I make extensive use of IDisposable to release internal resources such as pointers to parent classes.

It is quite easy to demonstrate the requirement by creating two mutually referential classes i.e. foo and bar. foo refers to bar and vice versa. When foo falls out of scope, the GC sees bar still refers to it so it is not collected (and vice versa). The memory is not collected.

This is the same style of problem exhibited by EventHandlers where the reference is not released when the form is closed unless it is explicitly released or the WeakEvent model is implemented.

I would suggest that best practice is to assume a C++ programming model where you clean up after yourself using Dispose unless you are convinced that the GC can work it out for you.