[2005] Try/Catch and Using

[DIYC]

Guys,

I'm fairly comfortable with the concept of Try/Catch/Finally but recently I'm trying to use the 'using' statement more often and this has confused me.

I have some code that looks like this....

        Using conSQL As New SqlConnection(ConnectionString)
            conSQL.Open()
            Using txSQL As SqlTransaction = conSQL.BeginTransaction
                Using cmdInsert1 As New SqlCommand("StoredProc1", conSQL, txSQL)
                    cmdInsert1.CommandType = CommandType.StoredProcedure
                    'add parameters here...
                    cmdInsert1.ExecuteNonQuery()
                End Using
                Using cmdInsert2 As New SqlCommand("StoredProc2", conSQL, txSQL)
                    cmdInsert2.CommandType = CommandType.StoredProcedure
                    'add parameters here...
                    cmdInsert2.ExecuteNonQuery()
                End Using
                txSQL.Commit()
            End Using
        End Using

Can anyone tell me how I should be using try/catch blocks in such code to handle exceptions?

Does the try/catch go inside the using statement or do I wrap the entire 'using block' in a try/catch?

Thanks in advance for your time, much appreciated.


Chris.

[jmcilhinney]

This code:

Dim myDisposableObject As New DisposableObject
 
Try
    'Do something here.
Catch
    'Handle error here.
Finally
    'Clean up here.
    myDisposableObject
End Try

is equivalent to this:

Using myDisposableObject As New DisposableObject
    Try
        'Do something here.
    Catch
        'Handle error here.
    End Try
End Using

The Using block simply makes the Finally block redundant, although there are still reasons that you'd use a Finally block apart from disposing.