Visual Basic

Protected Overrides Function ProcessKeyPreview(ByRef m As System.Windows.Forms.Message) As Boolean
    Select Case m.WParam.ToInt32()
        Case 37
            Me.DtRecordInfoBindingSource.MovePrevious()
            Return True
        Case 39
            Me.DtRecordInfoBindingSource.MoveNext()
            Return True
    End Select
    Return False
End Function

'Method 1
'If byteIn is null the function will return nothing.
'This function uses two (2) returns.
'I read that using the return statements is perfered (I don't know why).
'The catch will fire if byteIn is nothing.
Public Function ByteArrayToStream(ByRef byteIn() As Byte) As System.IO.MemoryStream
    Try
        Return New System.IO.MemoryStream(byteIn, True)
    Catch ex As Exception
        Return Nothing
    End Try
End Function

'Method 2
'If byteIn is null the function will return nothing.
'This function is assigning the result to the name of the procedure.
'The catch will fire if byteIn is nothing.
Public Function ByteArrayToStream(ByRef byteIn() As Byte) As System.IO.MemoryStream
    Try
        ByteArrayToStream = New System.IO.MemoryStream(byteIn, True)
    Catch ex As Exception
        ByteArrayToStream = Nothing
    End Try
End Function

'Method 3
'If byteIn is null the function will return nothing.
'This function is checking for null so the catch does not have to fire.
'I read somewhere that it is better to pre-check for possible error conditions.
'This function uses only 1 return statement, better?
'I believe there is extra memory overhead (ms2) with this method.
Public Function ByteArrayToStream(ByRef byteIn() As Byte) As System.IO.MemoryStream
    Dim ms2 As IO.MemoryStream = Nothing
    Try
        If byteIn Is Nothing Then Exit Try
        ms2 = New System.IO.MemoryStream(byteIn, True)
    Catch ex As Exception
        ms2 = Nothing
    End Try
    Return ms2
End Function

Private Function GetCategory(ByVal CategoryID) As Category

     Using mycon As New MySqlConnection(My.Settings.Orders)
         Dim myCat As New Category
         mycon.Open()
         'Code to return category her
         Return myCat
     End Using

 End Function

Try
      Dim newCategory As Category = GetCategory(myCatID)
Catch ex As MySqlException
      'error handling code here
End Try

Private Function GetCategory(ByVal CategoryID) As Category

        Dim mycon As New MySqlConnection(My.Settings.Orders)
        Try
            Dim myCat As New Category
            mycon.Open()
            Try
                'code to get category from db
            Catch ex As MySqlException
                Throw New DBReadException(ex.Message, ex)
            End Try
            Return myCat
        Catch ex As MySqlException
            Throw New DBOpenException(ex.Message, ex)
        Finally
            If mycon.State = ConnectionState.Open Then
                mycon.Close()
            End If
        End Try

    End Function