Question

Having read the threads Is SqlCommand.Dispose enough? and Closing and Disposing a WCF Service I am wondering for classes such as SqlConnection or one of the several classes inheriting from the Stream class does it matter if I close Dispose rather than Close?

Answer 1

I want to clarify this situation.

According to Microsoft guidelines, it’s a good practice to provide Close method where suitable. Here is a citation from Framework design guidelines

Consider providing method Close(), in addition to the Dispose(), if close is standard terminology in the area. When doing so, it is important that you make the Close implementation identical to Dispose …

In most of cases Close and Dispose methods are equivalent. The main difference between Close and Dispose in the case of SqlConnectionObject is:

An application can call Close more than one time. No exception is generated.

If you called Dispose method SqlConnection object state will be reset. If you try to call any method on disposed SqlConnection object, you will receive exception.

That said:

• If you use connection object one time, use Dispose. A using block will ensure this is called even in the event of an exception.
• If connection object must be reused, use Close method.