checking multiple textboxes for integers only, and if user copys and pastes

Question

Ok its been a while since i've done coding. So i thought would give it a shot again not doing too bad but having an issue with checking multiple textboxes to make sure only integers are present even when the user copies and pastes into the box. would like it to shift focus to the textboxes that don't have integers but not a necessity. Also i'm trying to run the check before i "call" the rest of my subs or functions. This is a windows form project using VB. currenty i have this as my button click event.

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

    Call current_year_values()
    Call retention_months()
    Call Individual_Retention_Months()
    Call future_retention()


End Sub

i was able to get this however the user can still copy and paste what ever they want into the text boxes.

Private Sub textboxgrosssubmit_KeyPress(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles textboxgrosssubmit.KeyPress
If Asc(e.KeyChar) <> 8 Then
If Asc(e.KeyChar) < 48 Or Asc(e.KeyChar) > 57 Then
e.Handled = True
End If
End If

End Sub

I have been researching the "try.parse" and found that seems the way to go, however i'm confused on how to set it up.

Thank you so much.

Answer 1

I think that you can remove the textboxgrosssubmit_KeyPress sub, and verify the data in Button1_Click:

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
   Dim g as Integer
   If Not Integer.TryParse(textboxgrosssubmit.Text, g) Then
      textboxgrosssubmit.Focus
      textboxgrosssubmit.SelectAll
      MsgBox("Bad data")
      Return
   End If

  Call current_year_values()
  Call retention_months()
  Call Individual_Retention_Months()
  Call future_retention()
End Sub

You can also validate other textboxes in the same manner and maybe create some helper functions with repetitive code.

Answer 2

Hi

Here is a stand alone example that may help. This example has a GroupBox1 with lots of different Controls in it. The code checks for valid integer entry and clears the TextBox if not (other actions could be done too). This is just a simple example to show the idea and has no error checking.

' Form1 with GroupBox1 contining
' several types of Control in prticular
' many TextBoxes
Option Strict On
Option Explicit On
Public Class Form1
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

        ' assign all TextBoxes in GroupBox1 to
        ' the same TextChanged Handler
        For Each c As Control In GroupBox1.Controls
            If c.GetType = GetType(TextBox) Then
                AddHandler DirectCast(c, TextBox).TextChanged, AddressOf TextBox_TextChanged
            End If
        Next
    End Sub

    Private Sub TextBox_TextChanged(sender As Object, e As EventArgs)
        Dim tb As TextBox = DirectCast(sender, TextBox)
        Dim v As Integer = 0
        If Integer.TryParse(tb.Text, v) Then
            ' valid integer so far
        Else
            ' if NOT a valid Integer the clear TextBox
            tb.Text = Nothing
        End If
    End Sub
    ' another way would be to add all the
    ' TextBox names to the Handles clause but
    ' if lots of TextBoxes it becomes unwieldy

End Class