VB.NET 2010 VALIDAR NUMEROS EN UN TEXTBOX

Private Sub TxtCantidad_KeyPress(sender As Object, e As System.Windows.Forms.KeyPressEventArgs) Handles TxtCantidad.KeyPress
If InStr(1, "0123456789,." & Microsoft.VisualBasic.ChrW(8), e.KeyChar) = 0 Then
e.Handled = True
End If
End Sub

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