小弟我碰到一个很菜的有关问题，但是就是看不出那里错了

2012-01-20

我碰到一个很菜的问题，但是就是看不出那里错了//主程序开始////////////////////////////////////////////

我碰到一个很菜的问题，但是就是看不出那里错了
//主程序开始/////////////////////////////////////////////////
i=0;
str_sbody= " ";
//初始化结束
ds=obj.oleds( "select * from class order by id desc ",0,0, "class ");
for(i=0;i <=ds.Tables[ "class "].Rows.Count-1;i+=1)
{
str_sbody=str_sbody+ " <table cellpadding=6 cellspacing=0 width=100% align=center bordercolor=#0099cc border=1> ";
str_sbody=str_sbody+ " <TR> <TD bgColor=#e8f4ff colSpan=6> "+ds.Tables[ "class "].Rows[i][ "class "].ToString()+ " </TD> </TR> ";

//版面信息
mycommand=new OleDbCommand( "select * from board where class= "+ds.Tables[ "class "].Rows[i][ "id "].ToString()+ " ",obj.link);
rs=mycommand.ExecuteReader();
while(rs.Read())
{
str_sbody=str_sbody+ " <TR> <TD vAlign=top width=* bgColor=#f2f8ff> ";
if(rs[ "icon "].ToString()!= " "&&rs[ "icon "].ToString()!=null)
{str_sbody=str_sbody+ " <img src=icon/ "+rs[ "icon "].ToString()+ ".gif board=0> ";
}
str_sbody=str_sbody+ " <a href=list.aspx?boardid= "+rs[ "boardid "].ToString()+ "> "+rs[ "boardtype "]+ " </a> <div align=right valign=top> <a href=announce.aspx?boardid= "+rs[ "boardid "].ToString()+ " title=快速发表主题> <img src=images/fpost2.gif border=0> </a> </div> ";
switch(rs[ "boardskin "].ToString())
{
case "2 ":str_sbody=str_sbody+ " 精华论坛（普通用户不能发帖） ";
break;
case "3 ":
str_sbody=str_sbody+ " 正规论坛（只准会员进入） ";
break;
case "4 ":
str_sbody=str_sbody+ " 认证论坛（必须经过认证） ";
break;
}
str_sbody=str_sbody+ " "+Server.HtmlEncode(rs[ "readme "].ToString())+ " </TD> ";
str_sbody=str_sbody+ " <TD vAlign=center align=middle bgColor=#e8f4ff width=80> ";
str_sbody=str_sbody+ " <img src= "+rs[ "indexIMG "].ToString()+ " board=0> "+master(rs[ "BoardMaster "].ToString());
str_sbody=str_sbody+ " </TD> <TD vAlign=center noWrap align=middle width=25 bgColor=#e8f4ff> "+rs[ "lasttopicnum "].ToString()+ "/ "+rs[ "todaynum "].ToString()+ " </TD> ";
str_sbody=str_sbody+ " <TD noWrap width=250 bgColor=#e8f4ff> 主题： ";

//列出最后的五编文章
OleDbCommand cmd2=new OleDbCommand( "select * from bbs1 where boardid= "+rs[ "boardid "].ToString()+ " ",obj.link);
rs2=cmd2.ExecuteReader(); *****到了这里就提示datareader已经打开，必须关闭
while(rs2.Read())

{str_sbody=str_sbody+ " <IMG border=0 src=images/arrow1.gif> "+rs2[ "topic "].ToString()+ " "+rs2[ "dateandtime "].ToString()+ "... ";

}
str_sbody=str_sbody+ " <a href=# target=_blank> 更多.. </a> ";
rs2.Close();

str_sbody=str_sbody+ " </TD> ";

//str_sbody=str_sbody+ " <a href= "+rs[ "filepath "].ToString()+ " target=_blank> "+rs[ "lasttopic "].ToString()+ "... </a> ";
//str_sbody=str_sbody+ " 最新发表： <a href=userdetail.aspx?username= "+rs[ "lastpostuser "].ToString()+ " target=_blank> "+rs[ "lastpostuser "].ToString()+ " </a> <IMG border=0 src=images/lastpost.gif> ";
//str_sbody=str_sbody+rs[ "lastposttime "].ToString()+ " </TD> ";

str_sbody=str_sbody+ " <TD vAlign=center noWrap align=middle width=25 bgColor=#f2f8ff> ";
str_sbody=str_sbody+ " <A href=javascript:window.external.AddFavorite( ' "+obj.bbsurl+ "/list.aspx?boardid= "+rs[ "boardid "].ToString()+ " ', ' "+obj.bbsname+ "-- "+rs[ "boardtype "].ToString()+ "（ "+obj.bbsurl+ "） ') target=_self> <img src=images/fav.gif border=0> </A> </TD> </TR> ";
}
str_sbody=str_sbody+ " </table> ";
rs.Close();
}//结束for
main.InnerHtml+=str_sbody;

本人刚学不久，还请各位大虾指点。

[解决办法]
也不说错误信息，而且看似ASP的，代码和界面混在一起，你叫别人怎么给你看？
[解决办法]
代码写的乱七八糟.改变算法!!!
不要把ASP的老思想用来写ASP.NET.
用数据绑定控件不是更好????干嘛还读一条数据,写一行HTML代码,累不累呀.
直接绑定,易懂也不容易出错.
[解决办法]
这个是asp.net的代码吗？
为什么要这样写？头大
[解决办法]
异常详细信息: System.InvalidOperationException: 已有打开的与此连接相关联的 DataReader，必须首先
================

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主　　题：我碰到一个很菜的问题，但是就是看不出那里错了
作　　者： zhangzhicong ()
等　　级：
信誉值： 100
所属论坛： .NET技术 ASP.NET
问题点数： 20
回复次数： 5
发表时间： 2007-9-9 12:23:39

//主程序开始/////////////////////////////////////////////////
i=0;
str_sbody= " ";
//初始化结束
ds=obj.oleds( "select * from class order by id desc ",0,0, "class ");
for(i=0;i <=ds.Tables[ "class "].Rows.Count-1;i+=1)
{
str_sbody=str_sbody+ " <table cellpadding=6 cellspacing=0 width=100% align=center bordercolor=#0099cc border=1> ";
str_sbody=str_sbody+ " <TR> <TD bgColor=#e8f4ff colSpan=6> "+ds.Tables[ "class "].Rows[i][ "class "].ToString()+ " </TD> </TR> ";

//版面信息
mycommand=new OleDbCommand( "select * from board where class= "+ds.Tables[ "class "].Rows[i][ "id "].ToString()+ " ",obj.link);
rs=mycommand.ExecuteReader();
while(rs.Read())
{
str_sbody=str_sbody+ " <TR> <TD vAlign=top width=* bgColor=#f2f8ff> ";

if(rs[ "icon "].ToString()!= " "&&rs[ "icon "].ToString()!=null)
{str_sbody=str_sbody+ " <img src=icon/ "+rs[ "icon "].ToString()+ ".gif board=0> ";
}
str_sbody=str_sbody+ " <a href=list.aspx?boardid= "+rs[ "boardid "].ToString()+ "> "+rs[ "boardtype "]+ " </a> <div align=right valign=top> <a href=announce.aspx?boardid= "+rs[ "boardid "].ToString()+ " title=快速发表主题> <img src=images/fpost2.gif border=0> </a> </div> ";
switch(rs[ "boardskin "].ToString())
{
case "2 ":str_sbody=str_sbody+ " 精华论坛（普通用户不能发帖） ";
break;
case "3 ":
str_sbody=str_sbody+ " 正规论坛（只准会员进入） ";
break;
case "4 ":
str_sbody=str_sbody+ " 认证论坛（必须经过认证） ";
break;
}
str_sbody=str_sbody+ " "+Server.HtmlEncode(rs[ "readme "].ToString())+ " </TD> ";
str_sbody=str_sbody+ " <TD vAlign=center align=middle bgColor=#e8f4ff width=80> ";
str_sbody=str_sbody+ " <img src= "+rs[ "indexIMG "].ToString()+ " board=0> "+master(rs[ "BoardMaster "].ToString());
str_sbody=str_sbody+ " </TD> <TD vAlign=center noWrap align=middle width=25 bgColor=#e8f4ff> "+rs[ "lasttopicnum "].ToString()+ "/ "+rs[ "todaynum "].ToString()+ " </TD> ";
str_sbody=str_sbody+ " <TD noWrap width=250 bgColor=#e8f4ff> 主题： ";

//列出最后的五编文章
OleDbCommand cmd2=new OleDbCommand( "select * from bbs1 where boardid= "+rs[ "boardid "].ToString()+ " ",obj.link);
rs2=cmd2.ExecuteReader(); *****到了这里就提示datareader已经打开，必须关闭
while(rs2.Read())
{str_sbody=str_sbody+ " <IMG border=0 src=images/arrow1.gif> "+rs2[ "topic "].ToString()+ " "+rs2[ "dateandtime "].ToString()+ "... ";

}
str_sbody=str_sbody+ " <a href=# target=_blank> 更多.. </a> ";
rs2.Close();

str_sbody=str_sbody+ " </TD> ";

//str_sbody=str_sbody+ " <a href= "+rs[ "filepath "].ToString()+ " target=_blank> "+rs[ "lasttopic "].ToString()+ "... </a> ";
//str_sbody=str_sbody+ " 最新发表： <a href=userdetail.aspx?username= "+rs[ "lastpostuser "].ToString()+ " target=_blank> "+rs[ "lastpostuser "].ToString()+ " </a> <IMG border=0 src=images/lastpost.gif> ";
//str_sbody=str_sbody+rs[ "lastposttime "].ToString()+ " </TD> ";

str_sbody=str_sbody+ " <TD vAlign=center noWrap align=middle width=25 bgColor=#f2f8ff> ";
str_sbody=str_sbody+ " <A href=javascript:window.external.AddFavorite( ' "+obj.bbsurl+ "/list.aspx?boardid = "+rs[ "boardid "].ToString()+ " ', ' "+obj.bbsname+ "-- "+rs[ "boardtype "].ToString ()+ "（ "+obj.bbsurl+ "） ') target=_self> <img src=images/fav.gif border=0> </A> </TD> </TR> ";
}
str_sbody=str_sbody+ " </table> ";
rs.Close();
}//结束for
main.InnerHtml+=str_sbody;

本人刚学不久，还请各位大虾指点。

回复人：zhangzhicong() ( 一级(初级)) 信誉：100 2007-9-9 12:30:40 得分:0

?

没有人顶，自己顶一下
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回复人：gui0605(技术诚可贵，英语价更高；若为金钱故，二着皆可抛！（誓把英语当方言）) ( 五级(中级)) 信誉：100 2007-9-9 12:36:25 得分:0
?

也不说错误信息，而且看似ASP的，代码和界面混在一起，你叫别人怎么给你看？
Top
回复人：zhangzhicong() ( 一级(初级)) 信誉：100 2007-9-9 12:42:53 得分:0
?

真不好意思，其实是这样的。
已有打开的与此连接相关联的 DataReader，必须首先将它关闭。
说明: 执行当前 Web 请求期间，出现未处理的异常。请检查堆栈跟踪信息，以了解有关该错误以及代码中导致错误的出处的详细信息。

异常详细信息: System.InvalidOperationException: 已有打开的与此连接相关联的 DataReader，必须首先将它关闭。

源错误:

行 144：OleDbCommand cmd2=new OleDbCommand( "select * from bbs1 where boardid= "+rs[ "boardid "].ToString()+ " ",obj.link);
rs.close();//这里先把DataReader关闭了
行 145：rs2=cmd2.ExecuteReader();
行 146：while(rs2.Read())
行 147：{

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Bad Request.