SqlDataReader问题
using System;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class manage_loginchek : System.Web.UI.Page
{
BaseClass bc = new BaseClass();
protected void Page_Load(object sender, EventArgs e)
{
string p_id = Request.Params[ "uid "].Trim();
string p_pass = Request.Params[ "pwd "].Trim();
SqlConnection conn = new SqlConnection(ConfigurationManager.AppSettings[ "conn "]);
string tSQL = "select u_name,u_flag from users where u_id= ' "+p_id+ " ' and u_pass= ' "+p_pass+ " 'order by id desc ";
try
{
SqlCommand mycommand = new SqlCommand(tSQL, conn);
conn.Open();
SqlDataReader reader = mycommand.ExecuteReader();
Session[ "name "] = reader[ "u_name "].ToString();
Session[ "flag "] = reader[ "u_flag "].ToString();
}
catch (System.Exception e)
{
conn.Close();
Response.Redirect( "login.aspx ");
}
//if (s == 1)
//{
// Session[ "flag "] = p_id;
// Response.Redirect( "adminindex.aspx ");
//}
}
}
大家看下，为什么会出错呢？
错误1不能在此范围内声明名为“e”的局部变量，因为这样会使“e”具有不同的含义，而它已在“父级或当前”范围中表示其他内容了c:\inetpub\wwwroot\federal_wh\manage\loginchek.aspx.cs319http://localhost/federal_wh/
[解决办法]
1。 DataReader 默认“游标”指向第一行数据之前，读取数据，得调用 Read 方法
2。 System.Exception e 变量冲突
[解决办法]
catch (System.Exception e)
==============
catch (System.Exception ex)
[解决办法]
catch (System.Exception e)
==============
catch (System.Exception ex)
[解决办法]
SqlCommand mycommand = new SqlCommand(tSQL, conn);
conn.Open();
SqlDataReader reader = mycommand.ExecuteReader(CommandBehavior.CloseConnection);
if(reader.HasRows)
{
if(reader.Read())
{
Session[ "name "] = reader[ "u_name "].ToString();
Session[ "flag "] = reader[ "u_flag "].ToString();
}
}
else
{
Response.Redirect( "login.aspx ");
}
