Information Technology Reference
In-Depth Information
I've spent some time now explaining why finalizers are not a good solution.
But yet, you still need to free resources. You address these issues using the
IDisposable interface and the standard dispose pattern. (See Item 17 later
in this chapter.)
To c l o s e , r e m e m b e r t h a t a m a n a g e d e n v i r o n m e n t , w h e r e t h e G a r b a g e
Collector takes the responsibility for memory management, is a big plus:
Memory leaks and a host of other pointer-related problems are no longer
your problem. Nonmemory resources force you to create finalizers to
ensure proper cleanup of those nonmemory resources. Finalizers can have
a serious impact on the performance of your program, but you must write
them to avoid resource leaks. Implementing and using the IDisposable
interface avoids the performance drain on the Garbage Collector that final-
izers introduce. The next section moves on to the specific items that will
help you create programs that use this environment more effectively.
Classes often have more than one constructor. Over time, it's easy for the
member variables and the constructors to get out of sync. The best way to
make sure this doesn't happen is to initialize variables where you declare
them instead of in the body of every constructor. You should utilize the ini-
tializer syntax for both static and instance variables.
Constructing member variables when you declare that variable is natural
in C#. Just initialize the variable when you declare it:
public class
MyClass
{
// declare the collection, and initialize it.
private
List
<
string
> labels =
new
List
<
string
>();
}
Regardless of the number of constructors you eventually add to the
MyClass type, labels will be initialized properly. The compiler generates
code at the beginning of each constructor to execute all the initializers you
have defined for your instance member variables. When you add a new
constructor, labels get initialized. Similarly, if you add a new member vari-
able, you do not need to add initialization code to every constructor; ini-
tializing the variable where you define it is sufficient. Equally important,
the initializers are added to the compiler-generated default constructor.
