小弟我想实现一个这样的SQLHELPER 来看看

using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Data.SqlClient;using System.Data;/// <summary>///SQLHELPER 的摘要说明/// </summary>public class SQLHELPER{    public static string connstr = @"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Database.mdf;Integrated Security=True;User Instance=True";    public static void runsql(string sqltext,string returntype,params SqlParameter[] p)    {        SqlConnection conn = new SqlConnection(connstr);        conn.Open();        SqlCommand comm = conn.CreateCommand();        comm.CommandText = sqltext;        foreach(SqlParameter ps in p)        {            comm.Parameters.Add(ps);        }        switch (returntype)        {             case "dr":                SqlDataReader dr = comm.ExecuteReader();                return dr;                break;            case "dt":                SqlDataAdapter da = new SqlDataAdapter();                DataTable dt = new DataTable();                da.Fill(dt);                conn.Close();                return dt;                break;            default:                comm.ExecuteNonQuery();                conn.Close();                break;        }    }}