Question

I’m working on a function that handles events from a number of buttons and trying to define a Select…Case based on the clicked button. Something like this…

   Private Sub btnClick(ByVal sender As System.Object, ByVal e As System.EventArgs) _
        Handles btnThis.Click, _
                btnThat.Click, _
                btnTheOther.Click
        Dim button_clicked As Button = CType(sender, Button)

        ...Do some common parts...

        Select button_clicked

            Case btnThis
                 ...Do this...

            Case btnThat
                 ...Do that...

            Case btnTheOther
                 ...Do the other...

            Case Else

        End Select

But I can’t get it to compile; it reports that “Operator = is not defined for types ‘System.Windows.Forms.Button’ and ‘System.Windows.Forms.Button'”. I’ve also tried

Select button_clicked

    Case btnThis.Equals

and

Select button_clicked

    Case btnThis.Equals(button_clicked)

Which don’t work either. Is there a way I can define a Select…Case in this manner or is it always destined to fail due to the attempt at comparison of reference types?

Answer 1

Using the control’s name is one option:

Private Sub btnClick(ByVal sender As Object, ByVal e As EventArgs) _
            Handles btnThis.Click, _
                    btnThat.Click, _
                    btnTheOther.Click

  Select DirectCast(sender, Button).Name
    Case btnThis.Name
      ...do this...
    Case btnThat.Name
      ...do that...
    Case btnTheOther.Name
      ...do the other...
    Case Else
      ...etc
  End Select
End Sub