Question

When i use the below function its showing the error message but still it give a error saying that the exception not unhandled. why is it?

Public Function DepartmentDelete(ByVal DepartmentID As Integer) As DataTable

    Try
        Using con As New SqlConnection(CMClass.GetConnectionString())
            Dim ds As DataTable = New DataTable
            con.Open()
            Dim command As SqlCommand = New SqlCommand("Department_Delete", con)
            command.Parameters.AddWithValue("@DepartmentID", DepartmentID)
            command.CommandType = CommandType.StoredProcedure
            Dim adapter As SqlDataAdapter = New SqlDataAdapter(command)
            Dim table As DataTable = New DataTable
            adapter.Fill(ds)
            Return ds
            con.Close()
        End Using
    Catch ex As SqlException
                 Throw New Exception(MsgBox(ex.Message))
        End
    End Try

End Function

Answer 1

You exception handler is correctly catching the SQLException.

The problem is in the following line in your handler:

Throw New Exception(MsgBox(ex.Message))

If you want the message box, then just use

MsgBox(ex.Message)

If you then want to bubble the exception you should then use the line

Throw

Don’t put the ex on the end of the Throw as this creates a new exception (specifically the full stacktrace) instead of rethrowing the old one, thereby masking some details of the actual problem.

In addition. If you do choose to rethrow the exception, you then need to catch it again somewhere further up the stack, otherwise you’ll still get the unhandled exception messages.