把WebForm数据导出到Excel中

上午给系统的订单管理部分添加了一个功能，把查询到的订单信息导出到excel，供管理员分析用。以前写的代码如下：

response.clear();
response.bufferoutput = true;
response.charset = "gb2312";
response.appendheader("content-disposition","attachment;filename = filename.xls");
response.contentencoding = encoding.getencoding("gb2312");
response.contenttype = "application/ms-excel";
this.enableviewstate = false;
system.globalization.cultureinfo myinfo = new system.globalization.cultureinfo("zh-cn", true);
stringwriter osw = new stringwriter(myinfo);
htmltextwriter ohtw = new htmltextwriter(osw);
dgqueryresult.rendercontrol(ohtw);
response.write(osw);
response.end(); 
        我的查询用了分页，客户要求把所有查询到的数据都导出到excel，所以不能象以前那样通过把控件的内容导出到excel来实现此功能，于是把代码改成这样：
   response.clear();
response.bufferoutput = true;
response.charset = "gb2312";
response.appendheader("content-disposition","attachment;filename = 订单.xls");
response.contentencoding = system.text.encoding.getencoding("gb2312");
response.contenttype = "application/ms-excel";
string strexcelheader = string.empty;
string strexcelitems;
if(viewstate["sql"] != null)    // 取前面查询用的sql语句
{
     // 取得各列标题，各标题之间以/t分割，最后一个列标题后加回车符 
     strexcelheader = "订单号/t经销商/t地区/t小类/t商品/t实付金额/t下单时间/t有效状态/t处理状态/t/n";                                     
    // 向http输出流中写入取得的数据信息 
    response.write(strexcelheader);   
         
    // 逐行处理查询结果数据 
    itdbhandle itdbhandle = new itdbhandle();
    itdbhandle.querystring = viewstate["sql"].tostring();
    sqldatareader reader = itdbhandle.executedatareader();      
    while(reader.read()) 
    { 
        strexcelitems = string.empty;
        strexcelitems += reader["orderid"].tostring() + "/t";   
        strexcelitems += reader["dealername"].tostring() + "/t";
        strexcelitems += reader["city"].tostring() + "/t";
        strexcelitems += reader["smallclassname"].tostring() + "/t";
        strexcelitems += reader["brandname"].tostring() + reader["model"].tostring() + "/t";
        strexcelitems += reader["totalprice"].tostring() + "/t";
        strexcelitems += reader["orderdate"].tostring() + "/t";
        strexcelitems += reader["isvalid"].tostring() + "/t";
        strexcelitems += reader["dealstate"].tostring()  +"/n";                                                  
        response.write(strexcelitems); 
   } 
    reader.close();
    response.end();
}   
       我这里只是简单的把查询到的数据以excel的形式write出来(当然也可以是其他格式，比如xml)，对简单的需求足矣了，当然，用.net直接去操作excel文件也是很简单的，有很多这样的例子可以参考。