Asp.Net2.0中GridView的DataFormatString="{0:yyyy-MM-dd}"不起作用解决办法

<Columns>                 <asp:BoundField DataField="EmployeeId" />                 <asp:BoundField DataField="LastName" />                 <asp:BoundField DataField="BirthDate" HtmlEncode ="false" DataFormatString="{0:yyyy-MM-dd}" /> </Columns>

注意红色部分 必须设置为false