Merci pour ces précisions.
Pourquoi ne pas utiliser la méthode static Double.TryParse pour tester s'il s'agit d'un chiffre ?
Vous pouvez aussi créer votre "numeric" textbox qui n'accepte que des chiffres, le point ou la virgule (en substituant si nécessaire). Voici un exemple de code que j'utilise pour un control WinForms mais ça peut vous inspirer pour créer le vôtre
en WPF. Ici, je rends possible un chiffre négative via la propriété adéquate.
Imports System.Windows.Forms
Imports System.Threading
Imports System.ComponentModel
Public Class NumericTextBox
Inherits TextBox
Public Sub New()
AllowDecimal = True
AllowNegative = True
End Sub
<DefaultValue(True),
Description("Indicates if the control accepts decimal number."),
Category("Behavior")>
Public Property AllowDecimal As Boolean
<DefaultValue(True),
Description("Indicates if the control accepts negative number."),
Category("Behavior")>
Public Property AllowNegative As Boolean
Protected Overrides Sub OnKeyPress(e As KeyPressEventArgs)
MyBase.OnKeyPress(e)
' first define the decimal separator defined for the current culture
Dim decimalSeparator = Thread.CurrentThread.CurrentUICulture.NumberFormat.NumberDecimalSeparator
' if the press key is the group separator (for example "." for nl) it will be converted to a decimal separator (for example "," for nl)
If e.KeyChar = Thread.CurrentThread.CurrentUICulture.NumberFormat.NumberGroupSeparator Then
e.KeyChar = decimalSeparator
End If
' if the key press is "." (from the numeric keyboard for example), and the group separator is not ".", convert to ","
If Thread.CurrentThread.CurrentUICulture.NumberFormat.NumberGroupSeparator <> "." And e.KeyChar = "." Then
e.KeyChar = decimalSeparator
End If
'only once a separator accepted
If e.KeyChar = decimalSeparator Then
If Not AllowDecimal Then
e.Handled = True
Return
End If
e.Handled = Me.Text.Contains(decimalSeparator)
If e.Handled = True Then Return
End If
' if negative allowed, sign only as first position
If e.KeyChar = "-" Then
e.Handled = Not AllowNegative Or Me.SelectionStart <> 0
Return
End If
' hex 8=backspace
' hex 127=del
' accept backspace (hex 8), del (hex 127), a decimalseparator or a number
e.Handled = Not (e.KeyChar = Convert.ToChar(&H8) _
OrElse e.KeyChar = Convert.ToChar(&H7F) _
OrElse e.KeyChar = decimalSeparator _
OrElse Char.IsNumber(e.KeyChar))
End Sub
End Class
