Information Technology Reference
In-Depth Information
The using Statement
It is imperative that certain types of objects be allowed to clean up and free the unmanaged
resources they are holding. The
using
statement is used to simplify the process and ensure that
these resources are properly disposed of.
A
resource
is a class or
struct
that implements the
System.IDisposable
interface. Inter-
faces are covered in detail in Chapter 17—but in short, an interface is a collection of
unimplemented function members that classes and
struct
s can choose to implement. The
IDisposable
interface contains a single method named
Dispose
.
The phases of using a resource are shown in Figure 9-10, and consist of the following:
Allocating the resource
Using the resource
Disposing of the resource
If an unexpected runtime error occurs during the portion of the code using the resource,
the code disposing of the resource might not get executed.
Figure 9-10.
Components of using a resource
■
Note
The
using
statement is different than the
using
directives. The
using
directives are covered in
Chapter 10.
