网上购物系统（Task005）——通用数据库访问函数集SqlHelper类

源代码：13033480群共享

六、代码页中的类SQLHelper

using System;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
using System.Collections.Generic;
using WestGarden.Model;

namespace WestGarden.Web
{
    public partial class Default6 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            IList<CategoryInfo> catogories = new List<CategoryInfo>();

            string connectionString = ConfigurationManager.ConnectionStrings["NetShopConnString"].ConnectionString;
            string cmdText = "SELECT * FROM Category";

            //使用静态类，可直接调用，不需要new。
            SqlDataReader rdr = SqlHelper.ExecuteReader(connectionString, CommandType.Text, cmdText,null);

            while (rdr.Read())
            {
                CategoryInfo category = new CategoryInfo(rdr.GetString(0), rdr.GetString(1), rdr.GetString(2));
                catogories.Add(category);
            }
            rdr.Close();

            repCategories.DataSource = catogories;
            repCategories.DataBind();
        }
    }

    //这个类是静态的，应用程序启动时，自动驻留在内存中，所建连接，在使用过程中，
    //也只是Close()，放回到连接池中。并没有注销Dispose()，可以下次连接时，快速使用。
    public abstract class SqlHelper
    {
        public static SqlDataReader ExecuteReader(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            SqlConnection conn = new SqlConnection(connectionString);

            try
            {
                //cmd.Connection = conn;
                //cmd.CommandType = cmdType;
                //cmd.CommandText = cmdText;
                
                //conn.Open();

                PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);

                //如果创建了 SqlDataReader 并将 CommandBehavior 设置为 CloseConnection，
                //则关闭 SqlDataReader 会自动关闭此连接。
                SqlDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                cmd.Parameters.Clear();
                return rdr;
            }
            catch
            {
                conn.Close();
                throw;
            }
            //finally
            //{
            //    conn.Close();
            //}
        }

        private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, CommandType cmdType, string cmdText, SqlParameter[] cmdParms)
        {

            if (conn.State != ConnectionState.Open)
                conn.Open();

            cmd.Connection = conn;
            cmd.CommandText = cmdText;

            if (trans != null)
                cmd.Transaction = trans;

            cmd.CommandType = cmdType;

            if (cmdParms != null)
            {
                foreach (SqlParameter parm in cmdParms)
                    cmd.Parameters.Add(parm);
            }
        }
    }
}

七、App_Code文件夹中的类SQLHelper.cs

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

namespace WestGarden.Web
{

    /// <summary>
    /// SQLHelper 的摘要说明
    /// </summary>
    //这个类是静态的，应用程序启动时，自动驻留在内存中，所建连接，在使用过程中，
    //也只是Close()，放回到连接池中。并没有注销Dispose()，可以下次连接时，快速使用。
    public abstract class SqlHelper
    {
        public static SqlDataReader ExecuteReader(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            SqlConnection conn = new SqlConnection(connectionString);

            try
            {
                //cmd.Connection = conn;
                //cmd.CommandType = cmdType;
                //cmd.CommandText = cmdText;

                //conn.Open();

                PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);

                //如果创建了 SqlDataReader 并将 CommandBehavior 设置为 CloseConnection，
                //则关闭 SqlDataReader 会自动关闭此连接。
                SqlDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                cmd.Parameters.Clear();
                return rdr;
            }
            catch
            {
                conn.Close();
                throw;
            }
            //finally
            //{
            //    conn.Close();
            //}
        }

        private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, CommandType cmdType, string cmdText, SqlParameter[] cmdParms)
        {

            if (conn.State != ConnectionState.Open)
                conn.Open();

            cmd.Connection = conn;
            cmd.CommandText = cmdText;

            if (trans != null)
                cmd.Transaction = trans;

            cmd.CommandType = cmdType;

            if (cmdParms != null)
            {
                foreach (SqlParameter parm in cmdParms)
                    cmd.Parameters.Add(parm);
            }
        }
    }
}

八、类库DBUtility中的类SQLHelper.cs

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

namespace WestGarden.DBUtility
{

    /// <summary>
    /// SQLHelper 的摘要说明
    /// </summary>
    //这个类是静态的，应用程序启动时，自动驻留在内存中，所建连接，在使用过程中，
    //也只是Close()，放回到连接池中。并没有注销Dispose()，可以下次连接时，快速使用。
    public abstract class SqlHelper
    {
        public static SqlDataReader ExecuteReader(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            SqlConnection conn = new SqlConnection(connectionString);

            try
            {
                //cmd.Connection = conn;
                //cmd.CommandType = cmdType;
                //cmd.CommandText = cmdText;

                //conn.Open();

                PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);

                //如果创建了 SqlDataReader 并将 CommandBehavior 设置为 CloseConnection，
                //则关闭 SqlDataReader 会自动关闭此连接。
                SqlDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                cmd.Parameters.Clear();
                return rdr;
            }
            catch
            {
                conn.Close();
                throw;
            }
            //finally
            //{
            //    conn.Close();
            //}
        }

        private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, CommandType cmdType, string cmdText, SqlParameter[] cmdParms)
        {

            if (conn.State != ConnectionState.Open)
                conn.Open();

            cmd.Connection = conn;
            cmd.CommandText = cmdText;

            if (trans != null)
                cmd.Transaction = trans;

            cmd.CommandType = cmdType;

            if (cmdParms != null)
            {
                foreach (SqlParameter parm in cmdParms)
                    cmd.Parameters.Add(parm);
            }
        }
    }
}

九、制作主界面Default.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="WestGarden.Web.Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>肯德基订餐系统——西园工作室</title>
</head>
<body>
    <form id="form1" runat="server">
        <asp:Panel ID="panFocus" runat="server" DefaultButton="btnSearch">
            <table align="center" border="0" cellpadding="0" cellspacing="0" width="780">
                <tr valign="top">
                    <td rowspan="2">
                        <img src="Images/Comm_Images/Logo_home.jpg" alt="home" /></td>
                    <td height="25" width="141">
                        <asp:TextBox ID="txtSearch" runat="server" CssClass="homeSearchBox" Width="130px"></asp:TextBox></td>
                    <td width="50">
                        <asp:ImageButton ID="btnSearch" runat="server" AlternateText="Search" CausesValidation="false"
                            CssClass="paddingSearchicon" ImageUrl="Images/Comm_Images/button-search.gif" /></td>
                    <td width="50">
                        <asp:LoginStatus ID="lgnStatus" runat="server" CssClass="homeLink" LoginText="登 录"
                            LogoutAction="Redirect" LogoutPageUrl="~/Default.aspx" LogoutText="退 出" />
                    </td>
                    <td width="64">
                    </td>
                </tr>
                <tr>
                    <td colspan="3">
                        <img src="Images/Comm_Images/KFC.JPG" /></td>
                    <td width="64">
                    </td>
                </tr>
            </table>
        </asp:Panel>
        <table align="center" border="0" cellpadding="0" cellspacing="0" width="780">
            <tr>
                <td width="112">
                </td>
                <td bgcolor="#FFFFFF" width="5">
                </td>
                <td bgcolor="#FFFFFF" height="5" width="436">
                </td>
                <td bgcolor="#FFFFFF" style=" 5px">
                </td>
                <td width="224">
                </td>
            </tr>
            <tr>
                <td>
                     </td>
                <td bgcolor="#FFFFFF">
                     </td>
                <td class="welcome">
                    欢迎光临肯德基订餐网站</td>
                <td bgcolor="#FFFFFF" style=" 5px">
                     </td>
                <td>
                     </td>
            </tr>
            <tr>
                <td colspan="5" height="1">
                </td>
            </tr>
            <tr>
                <td width="112">
                    <img height="290" src="Images/Comm_Images/door.jpg" width="112" alt="Sea Horse" /></td>
                <td bgcolor="#FFFFFF" width="5">
                     </td>
                <td valign="top" width="436">
                    <table border="0" cellpadding="0" cellspacing="0">
                        <tr>
                            <td>
                                打开菜单，会有精彩的发现，各种美味在向您招手</td>
                        </tr>
                        <tr>
                            <td>
                                等待着您的品尝．</td>
                        </tr>
                        <tr>
                            <td style="padding-left: 20px">
                                <asp:Repeater ID="repCategories" runat="server">
                                    <HeaderTemplate>
                                        <table cellspacing="0" border="0" style="border-collapse: collapse;">
                                    </HeaderTemplate>
                                    <ItemTemplate>
                                        <tr>
                                            <td>
                                                <asp:HyperLink runat="server" ID="lnkCategory" NavigateUrl='<%# string.Format("~/Items.aspx?page=0&categoryId={0}", Eval("CategoryId")) %>'
                                                    Text='<%# Eval("Name") %>' /><asp:HiddenField runat="server" ID="hidCategoryId" Value='<%# Eval("CategoryId") %>' />
                                            </td>
                                        </tr>
                                    </ItemTemplate>
                                    <FooterTemplate>
                                        </table>
                                    </FooterTemplate>
                                </asp:Repeater>
                                <p>
                                     </p>
                                <br />
                            </td>
                        </tr>
                    </table>
                </td>
                <td bgcolor="#FFFFFF" valign="top" style=" 5px">
                     </td>
                <td valign="top">
                    <img src="Images/Comm_Images/main_logo.gif" alt="西园软件出品" usemap="#mapWestGardenSoftWare"
                        border="0" /></td>
            </tr>
            <tr>
                <td>
                     </td>
                <td>
                     </td>
                <td>
                    Version 1.0 版权所有:西园电脑工作室.QQ交流群:13033480</td>
                <td style=" 5px">
                     </td>
                <td>
                     </td>
            </tr>
        </table>
        <map id="mapWestGardenSoftWare" name="西园软件">
            <area shape="rect" coords="240,235,140,300" href="http://blog.csdn.net/yousuosi"
                target="_blank" alt="西园电脑工作室" />
        </map>
    </form>
</body>
</html>

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