Do you need to dispose of objects and set them to null?

Question

Do you need to dispose of objects and set them to null, or will the garbage collector clean them up when they go out of scope?

Answer 1

If the object implements IDisposable, then yes, you should dispose it. The object could be hanging on to native resources (file handles, OS objects) that might not be freed immediately otherwise. This can lead to resource starvation, file-locking issues, and other subtle bugs that could otherwise be avoided.

See also Implementing a Dispose Method on MSDN.