小弟出学 各位大哥帮我看看吧 谢谢datagrid中dropdownlist update数据总有问题
实现代码为vb  
datagrid中的dropdownlist   在update数据库的时候总是出错   谢谢哥哥   姐姐帮我看看   本意是想点编辑摁钮后   dropdownlist   绑定某一列出现
'更新的事件
sub   mydatagrid_update(sender   as   object,e   as   datagridcommandeventargs)

strCon   =   ConfigurationSettings.AppSettings( "strCon ")  
conn   =   new   sqlconnection(strCon)
dim   txtid,txtName,txtPassword,txtClsid,txtStyid,txtEmail,txtIdc,txtdate   as   textbox

txtName   =   e.item.cells(3).controls(0)
txtPassword   =   e.item.cells(4).controls(0)
dim   txtRl   as   dropdownlist
txtRl   =   e.item.cells(5).controls(1)
txtClsid   =   e.item.cells(6).controls(0)
txtStyid   =   e.item.cells(7).controls(0)
txtEmail   =   e.item.cells(8).controls(0)
txtIdc   =   e.item.cells(9).controls(0)


dim   strSql   as   String
strSql= "Update   users   Set   User_name= ' "   &   txtName.text   &   " ',User_password= ' "   &   txtPassword.text   &   " '   ,User_roles= "   &   CInt(txtRl.selecteditem.text)   &   ",User_clsid= "   &   Clng(txtClsid.text)   &   ",User_styid= "   &   CInt(txtStyid.text)   &   ",User_email= ' "   &   txtEmail.text   &   " ',User_idc= ' "   &   txtIdc.text   &   " '   where   user_id   = "   &   mydatagrid.datakeys(CInt(e.item.itemindex))  
dim   cmd   as   sqlcommand
cmd   =   new   sqlcommand(strSql,conn)
dim   exp   as   exception
try
conn.open()
cmd.executenonquery()
conn.close()
message.text= "操作已成功! "
catch   exp
message.text   =   "更新时出现错误 "
end   try
mydatagrid.edititemindex   =   -1
call   binddata()
end   sub
在页面中
  <form     runat= "server ">
  <asp:datagrid   id   =   "mydatagrid "   headerstyle-backcolor   =   "#aaaadd "   width= "95% "  
  allowpaging= "true "   pagesize= "40 "   onpageindexchanged= "mydatagrid_page "  
  pagerstyle-horizontalalign= "right "   pagerstyle-mode= "numericpages "
  oneditcommand= "mydatagrid_edit "   oncancelcommand= "mydatagrid_cancel "   ondeletecommand= "mydatagrid_delete "
  onupdatecommand= "mydatagrid_update "   datakeyfield= "user_id "
  autogeneratecolumns   =   "false "   runat= "server "   >
<Columns>
<asp:editcommandcolumn   edittext= "编辑 "   updatetext= "更新 "   canceltext= "取消 "     itemstyle-wrap= "false "/>
<asp:buttoncolumn   text= "删除 "   commandName= "delete "   itemstyle-wrap= "false "/>
<asp:boundcolumn   headertext= "用户编号 "   datafield= "user_id "   readonly= "true "/>
<asp:boundcol