将.net中的datagrid的数据导出excel与读取excel
我导出的EXCEL读取出现 "外部表不是预期的格式 ",那位有做过.可以把源代码帖上让我看看吗?

------解决方案--------------------
SqlConnection conn=new SqlConnection(System.Configuration.ConfigurationSettings.AppSettings[ "conn "]);
SqlDataAdapter da=new SqlDataAdapter( "select * from tb1 ",conn);
DataSet ds=new DataSet();
da.Fill(ds, "table1 ");
DataTable dt=ds.Tables[ "table1 "];
string name=System.Configuration.ConfigurationSettings.AppSettings[ "downloadurl "].ToString()+DateTime.Today.ToString( "yyyyMMdd ")+new Random(DateTime.Now.Millisecond).Next(10000).ToString()+ ".xls ";//存放到 web.config中downloadurl指定的路径，文件格式为当前日期+4位随机数
FileStream fs=new FileStream(name,FileMode.Create,FileAccess.Write);
StreamWriter sw=new StreamWriter(fs,System.Text.Encoding.GetEncoding( "gb2312 "));
sw.WriteLine( "自动编号,姓名,年龄 ");
foreach(DataRow dr in dt.Rows)
{
sw.WriteLine(dr[ "ID "]+ ", "+dr[ "vName "]+ ", "+dr[ "iAge "]);
}
sw.Close();
Response.AddHeader( "Content-Disposition ", "attachment; filename= " + Server.UrlEncode(name));
Response.ContentType = "application/ms-excel ";// 指定返回的是一个不能被客户端读取的流，必须被下载
Response.WriteFile(name); // 把文件流发送到客户端
Response.End();
------解决方案--------------------
从datagrid导出html代码，生成excel文件，给客户端下载

优点：
1、有固定的格式，样子好看（datagrid的样子）

局限性：
1、不适合数据交换，里面有html代码，比较乱，没有固定格式
2、datagrid不能有分页、排序等，否则出错

实现方法：
Response.Clear();
Response.Buffer= false;
Response.Charset= "GB2312 ";
Response.AppendHeader( "Content-Disposition ", "attachment;filename=test.xls ");
Response.ContentEncoding=System.Text.Encoding.GetEncoding( "GB2312 "); Response.ContentType = "application/ms-excel "; this.EnableViewState = false;
System.IO.StringWriter oStringWriter = new System.IO.StringWriter();
System.Web.UI.HtmlTextWriter oHtmlTextWriter = new System.Web.UI.HtmlTextWriter(oStringWriter);
this.DataGrid1.RenderControl(oHtmlTextWriter);
Response.Write(oStringWriter.ToString());
Response.End();