SQL异常未处理，用户sa登录失败

用户sa登录失败

我一直在与sqlserver连接的。net c#项目上工作，我一直得到这个错误。"sql异常未处理"，用户sa登录失败，这是我的代码。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;
using System.Data;

namespace FrontOffice
{
   public class dblayer
    {
        #region DB Variables
        SqlConnection con = new SqlConnection("server=localhost;uid=sa;pwd=multi;database=officedb");
        SqlCommand cmd = new SqlCommand();
        SqlDataAdapter adp = new SqlDataAdapter();
         public SqlConnection con1 = new SqlConnection("server=localhost;uid=sa;pwd=multi;database=officedb");
        SqlDataReader rdr;
        #endregion
       SqlConnection opencon()
        {
            if (con.State == ConnectionState.Closed)
                con.Open();
            return con;
        }
       public SqlConnection Connect()
       {
           SqlConnection tempcon = new SqlConnection("server=localhost;uid=sa;pwd=multi;database=officedb");
           tempcon.Open();
           return tempcon;
       }
        #region Insert functions
        public bool newVisitorAdd(string name,string gender,string nation,string phone,string place,string catogory,string empid,string message)
        {
            cmd = new SqlCommand("exec visitadd @name,@gender,@nation,@phone,@place,@vcat,@empid,@message,@date,@time ",opencon());
            cmd.Parameters.AddWithValue("@name", (object)name);
            cmd.Parameters.AddWithValue("@gender", (object)gender);
            cmd.Parameters.AddWithValue("@nation", (object)nation);
            cmd.Parameters.AddWithValue("@phone", (object)phone);
            cmd.Parameters.AddWithValue("@place", (object)place);
            cmd.Parameters.AddWithValue("@vcat", (object)catogory);
            cmd.Parameters.AddWithValue("@empid", (object)empid);
            cmd.Parameters.AddWithValue("@message", (object)message);
            cmd.Parameters.AddWithValue("@date", (object)DateTime.Now.ToShortDateString());
            cmd.Parameters.AddWithValue("@time", (object)DateTime.Now.ToShortTimeString());
            int dd = cmd.ExecuteNonQuery();
            if (dd >= -1)
            {
                return true;
            }
            else
                return false;
        }
        public bool newvisitorimg(List<string> imglst, string name)
        {
            try
            {
                foreach (string img in imglst)
                {
                    cmd = new SqlCommand("insert into imgtb values('" + img + "','" + name + "')",opencon());
                    cmd.ExecuteNonQuery();
                }
                return true;
            }
            catch { return false; }
        }

        #endregion

        public SqlDataReader ExecuteReader(string qry)
        {
            try
            {
                cmd = new SqlCommand(qry, opencon());
                rdr = cmd.ExecuteReader();
                return rdr;
            }
            catch { return rdr; }
        }


        }
}

任何帮助都将是感激的，提前感谢!