.NET Resource Management - Effective C# - page 89

That's fine, unless any exceptions get thrown while the SQL command exe-
cutes. In that case, your calls to Dispose() never happen. The using state-
ment ensures that Dispose() is called. You allocate an object inside a using
statement, and the C# compiler generates a try / finally block around
each object:
public void ExecuteCommand( string connString,
string commandString)
{
using ( SqlConnection myConnection = new
SqlConnection (connString))
{
using ( SqlCommand mySqlCommand = new
SqlCommand (commandString,
myConnection))
{
myConnection.Open();
mySqlCommand.ExecuteNonQuery();
}
}
}
Whenever you use one Disposable object in a function, the using clause
is the simplest method to use to ensure that objects get disposed of prop-
erly. The using statement generates a try / finally block around the
object being allocated. These two blocks generate exactly the same IL:
SqlConnection myConnection = null ;
// Example Using clause:
using (myConnection = new SqlConnection (connString))
{
myConnection.Open();
}
// example Try / Catch block:
try
{
myConnection = new SqlConnection (connString);
myConnection.Open();
}