帮我找找错

[angellan]

HttpPostedFile file = FileTxt.PostedFile;
string fileName = Path.GetFileName(file.FileName);
file.SaveAs(Server.MapPath("~/" + fileName));

StreamReader sr = new StreamReader(fileName,Encoding.GetEncoding("GB2312"));
string sLine = sr.ReadLine();
StringBuilder sb = new StringBuilder();
while(sLine != null)
{
sb.Append(sLine);
}
Response.Write(sb.ToString());
应该是这样，谁能不能告诉我错在哪里了，要实现的功能是：要实现导入一个文件文件,获取文件里的信息,通过获取的信息进行查询,也就是批量查询,比如有一个文本文件,里面有10个学生的ID,第一个ID为一行,我要获取这10行信息,通过获取的信息再查询数据库,把查询到的信息显示到GridView中

[wxg22526451]

while(sLine != null)
{
sb.Append(sLine);
sLine = sr.ReadLine();
}

[wxg22526451]

StreamReader sr = new StreamReader(fileName,Encoding.GetEncoding("GB2312"));
-----------------》
StreamReader sr = new StreamReader(Server.MapPath("~/" + fileName),Encoding.GetEncoding("GB2312"));