datagrid如何手工绑定数据列呢

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<%@ Page Language="vb" Debug="true" %>
<%@import namespace="system.data"%>
<%@import namespace="system.data.sqlclient"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>职务维护</title>
</head>
<script language="VB" runat="server">
dim conn as sqlconnection
dim cmd as sqlcommand
dim reader as sqldatareader
dim ada as sqldataadapter
dim ds as dataset
sub bingding()
conn=new sqlconnection("data source=lzh\lzh;initial catalog=renshi;user id=sa;password=sql;")
conn.open()
ada=new sqldataadapter("select * from zw",conn)
ds=new dataset
ada.fill(ds,"zw")
datagrid1.datasource=ds.tables("zw").defaultview
datagrid1.databind()end sub
sub page_load(sender as object,e as eventargs)
if not ispostback then
bingding()
end if
end sub
sub datagrid_update(sender as object,e as datagridcommandeventargs)
dim zwmctxt as textbox=e.item.cells(2).controls(0)
dim zwid as string=e.item.cells(1).text
dim sqlstr,zwmc as string
zwmc=zwmctxt.text
sqlstr="update zw set zwmc='"+zwmc+"' where zwid='"+zwid+"'"
conn=new sqlconnection("data source=lzh\lzh;initial catalog=renshi;user id=sa;password=sql;")
conn.open()
cmd=new sqlcommand(sqlstr,conn)
cmd.executenonquery()
datagrid1.edititemindex=-1
bingding()
end sub
sub datagrid_cancel(sender as object,e as datagridcommandeventargs)
datagrid1.edititemindex=-1
bingding()
end subsub datagrid_edit(sender as object,e as datagridcommandeventargs)
datagrid1.edititemindex=e.item.itemindex
bingding()
end sub
</script>
<body>
<div align="center"><font color="#CC9966" size="+1"><b>职务维护</b></font></div>
<form runat="server">
<table cellpadding="2" cellspacing="0" border="1" width="85%">
<tr><td></td>
<td><asp:datagrid ID="datagrid1" runat="server" HeaderStyle-BackColor="#aaaadd" ItemStyle-BackColor="#c0c0c0"
 HeaderStyle-Font-Name="verdana" Font-Size="10px" Font-Name="verdana" border="1" BorderColor="red"
 CellPadding="2" CellSpacing="0" AutoGenerateColumns="false" Width="100%" DataKeyField="zwid"
 OnEditCommand="datagrid_edit"
 OnUpdateCommand="datagrid_update"
 OnCancelCommand="datagrid_cancel"
 > 
 <columns>
 <asp:editcommandcolumn
  EditText="编辑" UpdateText="更新" CancelText="取消" HeaderText="职务维护" ItemStyle-Wrap="false"
  HeaderStyle-Wrap="false"/>
 <asp:boundcolumn DataField="zwid" HeaderText="职务号" ReadOnly="true"/>
 <asp:boundcolumn DataField="zwmc" HeaderText="职务名称"/>
 </columns>
 </asp:datagrid>
 
 
 </td>
</tr>
</table>
</form>
</body>
</html>