Ext.net NumberField要设置MinValue,MaxValue

 <Items>
                <ext:NumberField ID="NumberField1" runat="server" FieldLabel="Age" />
                <ext:NumberField
                    ID="NumberField2"
                    runat="server"
                    FieldLabel="Test"
                    MinValue=""
                    MaxValue=""
                    AllowDecimals="true"
                    DecimalPrecision=""
                    Step="0.4"
                    />
            </Items>

如题，不然会报莫名其妙错误。