网上购物系统（Task004）——数据访问层DAL

一、添加类库dal，在dal中添加类category.cs，并在类库中添加函数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、使用用户控件

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：

[html] <%@ control language="c#" autoeventwireup="true" codefile="navigationcontrol.ascx.cs" inherits="westgarden.web.navigationcontrol" %> 
<%@ outputcache duration="100000" varybyparam="*" %> 
 
<: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> 
<%@ 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>
 

 

[csharp] 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();             
        } 
    } 
} 
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();           
        }
    }
}

三、为default.aspx添加主题westgarden并添加样式表stylesheet.css，在default.aspx中应用主题，删除default.aspx.cs代码页中的代码及default.aspx中reapeter控件，直接把用户控件拖入到页面中。

 

作者 yousuosi