网上购物系统(Task007)——自定义DateList控件分页显示商品信息

源代码:13033480群共享

一、数据集Model添加商品信息类ItemInfo.cs。

using System;

namespace WestGarden.Model
{
    public class ItemInfo
    {
        private int itemid;
        private string categoryid;
        private string name;
        private decimal price;
        private string image;
        private string categoryname;

        public ItemInfo() { }

        public ItemInfo(int itemid, string categoryid, string name, decimal price, string image, string categoryname)
        {
            this.itemid = itemid;
            this.categoryid = categoryid;
            this.name = name;
            this.price = price;
            this.image = image;
            this.categoryname = categoryname;
        }

        public int ItemId
        {
            get { return itemid; }
            set { itemid = value; }
        }
        public string CategoryId
        {
            get { return categoryid; }
            set { categoryid = value; }
        }
        public string Name
        {
            get { return name; }
            set { name = value; }
        }
        public decimal Price
        {
            get { return price; }
            set { price = value; }
        }
        public string Image
        {
            get { return image; }
            set { image = value; }
        }
        public string CategoryName
        {
            get { return categoryname; }
            set { categoryname = value; }


        }
    }
}

二、数据访问层DAL中添加类Item.cs,并添加函数GetItemsByCategory()

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

using WestGarden.Model;
using WestGarden.DBUtility;

namespace WestGarden.DAL
{
    public class Item
    {
        private const string SQL_SELECT_ITEMS_BY_CATEGORY = "SELECT Item.ItemId,Item.CategoryId,Item.Name,Item.Price,Item.Image,Category.Name FROM Item INNER JOIN Category ON Item.CategoryId=Category.CategoryId WHERE Item.CategoryId = @CategoryId";
        private const string PARM_CATEGORY_ID = "@CategoryId";

        public IList<ItemInfo> GetItemsByCategory(string CagegoryId)
        {

            IList<ItemInfo> itemsByCategory = new List<ItemInfo>();

            SqlParameter parm = new SqlParameter(PARM_CATEGORY_ID, SqlDbType.VarChar, 20);
            parm.Value = CagegoryId;

            //Execute the query against the database
            using (SqlDataReader rdr = SqlHelper.ExecuteReader(SqlHelper.ConnectionStringLocalTransaction, CommandType.Text, SQL_SELECT_ITEMS_BY_CATEGORY, parm))
            {
                // Scroll through the results
                while (rdr.Read())
                {
                    ItemInfo item = new ItemInfo(rdr.GetInt32(0), rdr.GetString(1), rdr.GetString(2), rdr.GetDecimal(3), rdr.GetString(4), rdr.GetString(5));
                    itemsByCategory.Add(item);
                }
            }
            return itemsByCategory;
        }
    }
}
三、DataList显示商品信息
1、  Item.aspx
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Items1.aspx.cs" Inherits="WestGarden.Web.Items1" %>

<!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">
    <div>
        <asp:DataList ID="dlstItems" runat="server">
            <ItemTemplate>
                 <table cellpadding="0" cellspacing="0">
                    <tr>
                        <td>
                            <asp:Image ID="imgItem" runat="server" AlternateText='<%# Eval("Name") %>' Height="120"
                                ImageUrl='<%# Eval("Image") %>' Width="120" />
                        </td>
                    </tr>
                    <tr>
                        <td>
                            <%# Eval("Name") %>
                        </td>
                    </tr>
                    <tr>
                        <td>
                            <%# Eval("Price") %>
                        </td>
                    </tr>
                </table>
            </ItemTemplate>
        </asp:DataList></div>

    </form>
</body>
</html>

2、Item.aspx.cx

using WestGarden.DAL;

namespace WestGarden.Web
{
    public partial class Items1 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            string categoryKey = Request.QueryString["categoryId"];
            Item item =new Item();
            dlstItems.DataSource = item.GetItemsByCategory(categoryKey);
            dlstItems.DataBind();

        }
    }
}


 

四、自定义DataList分页显示商品信息

1、自定义控件CustomList.cs,添加分页功能。

using System;
using System.Collections;
using System.Collections.Specialized;
using System.Text;
using System.Text.RegularExpressions;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace WestGarden.Web {

    public class CustomList : DataList {
        //Static constants
        protected const string HTML1 = "<table cellpadding=0 cellspacing=0><tr><td colspan=2>";
        protected const string HTML2 = "</td></tr><tr><td class=paging align=left>";
        protected const string HTML3 = "</td><td align=right class=paging>";
        protected const string HTML4 = "</td></tr></table>";
        private static readonly Regex RX = new Regex(@"^&page=\d+", RegexOptions.Compiled);
        private const string LINK_PREV = "<a href=?page={0}>< 上一页</a>";
        private const string LINK_MORE = "<a href=?page={0}>下一页 ></a>";
        private const string KEY_PAGE = "page";
        private const string COMMA = "?";
        private const string AMP = "&";

        protected string emptyText;
        private IList dataSource;
        private int pageSize = 10;
        private int currentPageIndex;
        private int itemCount;

        override public object DataSource {
            set {
                //This try catch block is to avoid issues with the VS.NET designer
                //The designer will try and bind a datasource which does not derive from ILIST
                try {
                    dataSource = (IList)value;
                    ItemCount = dataSource.Count;
                }
                catch {
                    dataSource = null;
                    ItemCount = 0;
                }
            }
        }

        public int PageSize {
            get { return pageSize; }
            set { pageSize = value; }
        }

        protected int PageCount {
            get { return (ItemCount - 1) / pageSize; }
        }

        virtual protected int ItemCount {
            get { return itemCount; }
            set { itemCount = value; }
        }

        virtual public int CurrentPageIndex {
            get { return currentPageIndex; }
            set { currentPageIndex = value; }
        }

        public string EmptyText {
            set { emptyText = value; }
        }

        public void SetPage(int index) {
            OnPageIndexChanged(new DataGridPageChangedEventArgs(null, index));
        }

        override protected void OnLoad(EventArgs e) {
            if (Visible) {
                string page = Context.Request[KEY_PAGE];
                int index = (page != null) ? int.Parse(page) : 0;
                SetPage(index);
            }
        }


        /// <summary>
        /// Overriden method to control how the page is rendered
        /// </summary>
        /// <param name="writer"></param>
        override protected void Render(HtmlTextWriter writer) {

            //Check there is some data attached
            if (ItemCount == 0) {
                writer.Write(emptyText);
                return;
            }

            //Mask the query
            string query = Context.Request.Url.Query.Replace(COMMA, AMP);
            query = RX.Replace(query, string.Empty);

           
            // Write out the first part of the control, the table header
            writer.Write(HTML1);

            // Call the inherited method
            base.Render(writer);
            
            // Write out a table row closure
            writer.Write(HTML2);

            //Determin whether next and previous buttons are required
            //Previous button?
            if (currentPageIndex > 0)
                writer.Write(string.Format(LINK_PREV, (currentPageIndex - 1) + query));

            //Close the table data tag
            writer.Write(HTML3);

            //Next button?
            if (currentPageIndex < PageCount)
                writer.Write(string.Format(LINK_MORE, (currentPageIndex + 1) + query));

            //Close the table
            writer.Write(HTML4);
        }

        override protected void OnDataBinding(EventArgs e) {

            //Work out which items we want to render to the page
            int start = CurrentPageIndex * pageSize;
            int size = Math.Min(pageSize, ItemCount - start);

            IList page = new ArrayList();

            //Add the relevant items from the datasource
            for (int i = 0; i < size; i++)
                page.Add(dataSource[start + i]);

            //set the base objects datasource
            base.DataSource = page;
            base.OnDataBinding(e);

        }

        public event DataGridPageChangedEventHandler PageIndexChanged;

        virtual protected void OnPageIndexChanged(DataGridPageChangedEventArgs e) {
            if (PageIndexChanged != null)
                PageIndexChanged(this, e);
        }
    }
}


 

2、用户控件

1ItemssControl.ascx

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Items1.aspx.cs" Inherits="WestGarden.Web.Items1" %>

<!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">
    <div>
        <asp:DataList ID="dlstItems" runat="server">
            <ItemTemplate>
                 <table cellpadding="0" cellspacing="0">
                    <tr>
                        <td>
                            <asp:Image ID="imgItem" runat="server" AlternateText='<%# Eval("Name") %>' Height="120"
                                ImageUrl='<%# Eval("Image") %>' Width="120" />
                        </td>
                    </tr>
                    <tr>
                        <td>
                            <%# Eval("Name") %>
                        </td>
                    </tr>
                    <tr>
                        <td>
                            <%# Eval("Price") %>
                        </td>
                    </tr>
                </table>
            </ItemTemplate>
        </asp:DataList></div>

    </form>
</body>
</html>


2ItemssControl.ascx.cs

using System;
using System.Web;
using System.Web.UI.WebControls;
using WestGarden.DAL;

namespace WestGarden.Web {

    public partial class ItemsControl : System.Web.UI.UserControl {

        /// <summary>
        /// Rebind control 
        /// </summary>
        protected void PageChanged(object sender, DataGridPageChangedEventArgs e) {
            //reset index
            dlstItems.CurrentPageIndex = e.NewPageIndex;

            //get category id
            string categoryKey = Request.QueryString["categoryId"];

            //bind data
            Item item = new Item();
           dlstItems.DataSource = item.GetItemsByCategory(categoryKey);
            dlstItems.DataBind();
        }
    }
}

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原文地址:https://www.cnblogs.com/java20130723/p/3211708.html