Question

I working on a project that includes to call a certain type of method to each control, i have this code:

 Private Sub txtBcNum1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles txtBcNum1.KeyPress

    If Char.IsDigit(e.KeyChar) Or e.KeyChar = Chr(8) Then
        e.Handled = False
    Else
        e.Handled = True
    End If

End Sub

This code works like a charm if i want to allow only numbers and backspace on my textbox.

Problem:
I have 15 textboxes( txtBcNum1,txtBcNum2,….,txtBcNum15 ), what’s the best way to call this function inside KeyPress method on each textboxes with out manually adding it to KeyPress method?

Answer 1

You can add more than one control to the Handles clause:

Private Sub txtBcNum1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) _
            Handles txtBcNum1.KeyPress, txtBcNum2.KeyPress, txtBcNum3.Keypress, ...

This way your sub will be called for every control. If you want to reuse this code across different forms, it might be a good idea to create a new control, inherited from Textbox, which might be called NumericTextBox and handle its own KeyPress event. That way you wouldn’t have to add any code in forms that use this control.

Also, have you considered using the built-in NumericUpDown control which serves the same purpose?