后台数据使用datareader方法

using System;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
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;

/// <summary>
/// Summary description for DataManager
/// </summary>
public sealed class DataManager
{
    private SqlConnection _connection;

    #region Constructors
    private static DataManager instance = new DataManager();
    public static DataManager Default
    {
        get
        {
            return instance;
        }
    }

    private DataManager()
    {
    }
    #endregion Constructor

    private SqlConnection RequestConnection()
    {
        // TODO: Add logic
        SqlConnection connection = new SqlConnection(ConfigurationManager.ConnectionStrings[Parameters.DefaultConnectionName].ConnectionString);
        connection.Open();
        return connection;
    }
    private void ReleaseConnect(SqlConnection connection)
    {
        // TODO Here
        if (connection == null)
        {
            throw new ArgumentNullException("connection");
        }

        //connection.Close();
    }

    public int ExecuteCommand(string text)
    {
        if (text == null)
        {
            throw new ArgumentNullException("text");
        }

        SqlConnection connection = null;
        try
        {
            connection = this.RequestConnection();
            SqlCommand command = new SqlCommand(text, connection);
            return command.ExecuteNonQuery();
        }
        catch (SqlException exception)
        {
            return -1;
        }
        finally
        {
            this.ReleaseConnect(connection);
        }


    }

    public SqlDataReader ExecuteCommandAndReturnReader(string text)
    {
        if (text == null)
        {
            throw new ArgumentNullException("text");
        }

        SqlConnection connection = null;
        try
        {
            connection = this.RequestConnection();
            SqlCommand command = new SqlCommand(text, connection);
            return command.ExecuteReader();
        }
        catch (Exception e)
        {
            return null;
        }
        finally
        {
            this.ReleaseConnect(connection);
        }
    }

    public SqlDataReader ExecuteSpCommandAndReturnReader(string text)
    {
        if (text == null)
        {
            throw new ArgumentNullException("text");
        }

        SqlConnection connection = null;
        try
        {
            connection = this.RequestConnection();
            SqlCommand command = new SqlCommand(text, connection);
            command.CommandType = CommandType.StoredProcedure;
            return command.ExecuteReader();
        }
        catch (Exception e)
        {
            return null;
        }
        finally
        {
            this.ReleaseConnect(connection);
        }
    }

    public SqlDataReader ExecuteSpCommandAndReturnReader(string text,string parameter, int id)
    {
        if (text == null)
        {
            throw new ArgumentNullException("text");
        }

        SqlConnection connection = null;
        try
        {
            connection = this.RequestConnection();
            SqlCommand command = new SqlCommand(text, connection);
            command.CommandType = CommandType.StoredProcedure;
            command.Parameters.Add(parameter, SqlDbType.Int).Value = id;
            return command.ExecuteReader();
        }
        catch (Exception e)
        {
            return null;
        }
        finally
        {
            this.ReleaseConnect(connection);
        }
    }


}