How do I evaluate textbox input?

How do I evaluate textbox input?

• Wolf-Michael Haberichter

  Hi,
  tReXx's code is fine, but the user must be unable to write "." more than one time, so I edited his code :
  

  Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
    Dim LIString As String = TextBox1.Text & "."
    If InStr("1234567890." & Chr(8), e.KeyChar) = 0 Or (e.KeyChar = "." And LIString.IndexOf(".") <> LIString.LastIndexOf(".")) Then e.Handled = True
  End Sub

  Hope this helps.
  
  
  

• ErinActuateDeveloper

  just set a a string like:
  
  Dim sString as string = "0123456789" & chr(8)
  
  then use the keydown event of the textbox
  
  If InStr(1, sString, e.KeyChar) = 0 Then e.Handled = True
  
  Done
  
  
  same string u can use after pasting.
  
  just the textbox to chars who aint containd in sstring and use the sstring.remove() methode
  
  

• N. Soltic

  To use IsNumeric function :
  

  Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
    If IsNumeric(TextBox1.Text & e.KeyChar) = False And Asc(e.KeyChar) <> 8 Then e.Handled = True
  End Sub

  
  
  
  

• Juraj Borza

  Have you considered the IsNumeric property

  
  
  
• How do I evaluate textbox input?