为什么datalist的RepeatColumns不起作用（没分了）


我想一行显示3列。已经设置RepeatColumns="3" RepeatDirection="Horizontal"
但还是每行显示一列
<asp:datalist id="datalist1" Width="100%" Runat="server" ForeColor="Black" AlternatingItemStyle-BackColor="#f3f3f3"
CellPadding="0"   RepeatColumns="3" BorderColor="Tan" BackColor="LightGoldenrodYellow" BorderWidth="1px" DataKeyField="WTTOOL" RepeatDirection="Horizontal">
<SelectedItemStyle ForeColor="GhostWhite" BackColor="DarkSlateBlue"></SelectedItemStyle>
<HeaderTemplate>
<table cellSpacing="1" cellPadding="1" border="0" style="border:1px solid black;">
<tr bgColor="#6B696B">
<td Class="header2">刪除</td>
<td id="aa1" Class="header2" height="20" width="30">查看</td>
<td id="a1">
<asp:Label id="Label1" CssClass="header2" Width="100" runat="server" Text='成品半制品編號'></asp:Label></font></td>
<td id="a3">
<asp:Label id="Label3" CssClass="header2" runat="server" Text='成品半制品描述'></asp:Label></font></td>
<td id="a2">
<asp:Label id="Label2" CssClass="header2" runat="server" Text='模具編號'></asp:Label></font></td>
<td id="a4">
<asp:Label id="Label4" CssClass="header2" runat="server" Text='模具描述'></asp:Label></font></td>

</tr>
</HeaderTemplate>
<AlternatingItemStyle BackColor="PaleGoldenrod"></AlternatingItemStyle>
<FooterTemplate>
</table>
</FooterTemplate>
<ItemTemplate>
<tr bgColor="#F7F7DE" onmouseover="this.style.backgroundColor='#CE5D5A'" onmouseout="this.style.backgroundColor=''">
<td><input type="hidden" id="SelectedID" runat="server"   value='<%# DataBinder.Eval(Container.DataItem,"WTPROD")%>'  NAME="SelectedID"/>
<input type="hidden" id="SelectedID2" runat="server"   value='<%# DataBinder.Eval(Container.DataItem,"WTTOOL")%>'  NAME="SelectedID2"/>
<asp:CheckBox ID="chkExport" runat="server" /></td>
<td id="1b" width="50px">
<asp:Button id="edit" runat="server" Text="查看" CommandName="edit"></asp:Button>
</td>
<td id="1" width="50px">
<asp:Label CssClass="header" ID="WTPROD" Width="100" runat="server" Text='<%#DataBinder.Eval(Container.DataItem,"WTPROD")%>'>
</asp:Label></font></td>
<td id="3" width="400px">
<asp:Label CssClass="header" ID="WTFDES" Width="150" runat="server" Text='<%#DataBinder.Eval(Container.DataItem,"WTFDES")%>'>
</asp:Label></font></td>
<td id="2">
<asp:Label CssClass="header" ID="WTTOOL" Width="100" runat="server" Text='<%#DataBinder.Eval(Container.DataItem,"WTTOOL")%>' >
</asp:Label></font></td>
<td id="4">
<asp:Label CssClass="header" ID="WTTDES" Width="140" runat="server" Text='<%#DataBinder.Eval(Container.DataItem,"WTTDES")%>'>
</asp:Label></font></td>
<td id="5">
<asp:Label CssClass="header" ID="WTTEQU" Width="100" runat="server" Text='<%#DataBinder.Eval(Container.DataItem,"WTTEQU")%>'>
</asp:Label></font></td>

</tr>
</ItemTemplate>
<FooterStyle BackColor="Tan"></FooterStyle>
<HeaderStyle Font-Bold="True" BackColor="Tan"></HeaderStyle>
</asp:datalist>