Fugerar om jag skapar hela kontrollen code-behind ! :-/
i Page_Load:
Dim rx as RegularExpressionValidator = New RegularExpressionValidator()
rx.ErrorMessage = "Ej tillåtet filformat"
rx.ControlToValidate="myFile"
rx.Display = ValidatorDisplay.Dynamic
rx.Attributes.Add
phv.Controls.Add(rx)
.aspx
<asp:PlaceHolder id="phv" runat="server"></asp:PlaceHolder>
<input id="myFile" type="file" name="myFile" runat="server">
<input id="Submit1" type="Submit" value="Ladda upp fil" runat="server">
<asp:requiredfieldvalidator id="Requiredfieldvalidator1"
runat="server" ErrorMessage="Du måste ange en fil"
ControlToValidate="myFile" Display="Dynamic">