Question

I have 44 text boxes on a screen (to be precise, RadNumericTextBoxes but that’s not germane). They follow a common naming pattern (rntb_[NameOfDBField]) which can’t be programmatically replicated.

How can I set .Value to Nothing for each control which has a name ^= rntb_? I have attempted the following:

Private Sub ClearValues()
    For Each c as Control in Controls
        If TypeOf c Is RadNumericTextBox Then
            TryCast(c, RadNumericTextBox).Value = Nothing
        End If
    Next
End Sub

However, Controls.Count = 1 and contains just the name of the master page.

Do I need to pass an argument to Controls, or do I need to do something else altogether? It’s “only” 44 text boxes so I could clear each one manually but I’d rather do it programmatically if possible.

Answer 1

If the RadNumericTextBoxes are on the Form and not in a container, then something along the lines of

Private Sub ClearValues()
    For Each c As Control In Me.Controls
        If TypeOf c Is RadNumericTextBox Then
            Dim rntb = DirectCast(c, RadNumericTextBox)
            If rntb.Name.StartsWith("rntb_") Then
                rntb.Value = Nothing
            End If
        End If
    Next
End Sub

But if they are in, say, GroupBox1 then you would replace Me.Controls in the above with GroupBox1.Controls.

And what is the End For in your code? A For..Next loop has Next at the end of its body in VB.NET.