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网上购物系统(Task005)——自定义DateList控件分页显示商品信息

程序员文章站 2024-01-28 20:33:28
一、数据集Model添加商品信息类ItemInfo.cs。   [csharp] using System;    namespace Wes...

一、数据集Model添加商品信息类ItemInfo.cs。

 

[csharp] 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; } 
 
 
        } 
    } 

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()

[csharp] 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; 
        } 
    } 

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[html] <%@ 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"> 
    <p> 
        <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></p> 
 
    </form> 
</body> 
</html> 
<%@ 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">
    <p>
        <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></p>

    </form>
</body>
</html>
 
2、Item.aspx.cx

 
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}>&#060;&nbsp;上一页</a>";
        private const string LINK_MORE = "<a href=?page={0}>下一页&nbsp;&#062;</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

1、ItemssControl.ascx

 

[html] <%@ 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"> 
    <p> 
        <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></p> 
 
    </form> 
</body> 
</html> 
<%@ 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">
    <p>
        <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></p>

    </form>
</body>
</html>
 

 

2、ItemssControl.ascx.cs

 

[csharp] 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(); 
        } 
    } 

 

作者 yousuosi