网上购物系统（Task006）——数据访问层DAL

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mb61b856e04bb98 2021-12-21 10:30:40

文章标签 sql perl 用户控件 文章分类 代码人生

一、数据访问层DAL

1、添加类库DAL，设置类库项目的程序集名称和默认命名空间；

2、在DAL中添加类Category.cs，设置类的属性为public；

3、在类Category.cs中添加函数GetCategories(),代码如下：

using System;

using System.Data;

using System.Collections.Generic;

using System.Text;

using System.Data.SqlClient;

using WestGarden.Model;

using WestGarden.DBUtility;

namespace WestGarden.DAL

{

public class Category

{

// Static constants

private const string SQL_SELECT_CATEGORIES = "SELECT CategoryId, Name, Descn FROM Category";

/// <summary>

/// Method to get all categories

/// </summary>

public IList<CategoryInfo> GetCategories()

{

IList<CategoryInfo> categories = new List<CategoryInfo>();

//Execute a query to read the categories

using (SqlDataReader rdr = SqlHelper.ExecuteReader(SqlHelper.ConnectionStringLocalTransaction, CommandType.Text, SQL_SELECT_CATEGORIES, null))

{

while (rdr.Read())

{

CategoryInfo cat = new CategoryInfo(rdr.GetString(0), rdr.GetString(1), rdr.GetString(2));

categories.Add(cat);

}

return categories;

}

函数GetCategories()要在SQLHelper中读取连接字符串，因此，需要在SQLHelper.cs中添加代码：

public static readonly string ConnectionStringLocalTransaction =ConfigurationManager.ConnectionStrings["NetShopConnString"].ConnectionString;

注意添加引用System.Configuration。

二、应用层Web

1、在Web中新建文件夹Controls并在其中添加用户控件NavigationControl.ascx，窗体页和代码页代码分别如下：

<%@ Control Language="C#" AutoEventWireup="true" CodeFile="NavigationControl.ascx.cs" Inherits="WestGarden.Web.NavigationControl" %>
<%@ OutputCache Duration="100000" VaryByParam="*" %>
<asp:Repeater ID="repCategories" runat="server">
<HeaderTemplate>
<table cellspacing="0" border="0" style="border-collapse: collapse;">
</HeaderTemplate>
<ItemTemplate>
<tr>
<td class="<%= ControlStyle %>"><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>

using System;
using System.Web.UI.WebControls;
using WestGarden.DAL;
namespace WestGarden.Web {
    public partial class NavigationControl : System.Web.UI.UserControl {

        private string controlStyle;
        protected string ControlStyle {
            get { return controlStyle; }
        }

        protected void GetControlStyle() {
            if (Request.ServerVariables["SCRIPT_NAME"].ToLower().IndexOf("default.aspx") > 0)
                controlStyle = "navigationLinks";
            else
                controlStyle = "mainNavigation";
        }

        protected void Page_Load(object sender, EventArgs e) {
            GetControlStyle();
            BindCategories();
            string categoryId = Request.QueryString["categoryId"];
            if (!string.IsNullOrEmpty(categoryId))
                SelectCategory(categoryId);
        }
        private void SelectCategory(string categoryId) {
            foreach (RepeaterItem item in repCategories.Items) {
                HiddenField hidCategoryId = (HiddenField)item.FindControl("hidCategoryId");
                if(hidCategoryId.Value.ToLower() == categoryId.ToLower()) {
                    HyperLink lnkCategory = (HyperLink)item.FindControl("lnkCategory");
                    lnkCategory.ForeColor = System.Drawing.Color.FromArgb(199, 116, 3);
                    break;
                }
            }
        }
        private void BindCategories() {
            Category category = new Category();
            repCategories.DataSource = category.GetCategories();
            repCategories.DataBind();            
        }
    }
}