• [网络收集]利用Session对象实现购物车


    //shopcart.aspx.cs

    using System;
    using System.Data;
    using System.Configuration;
    using System.Collections;
    using System.Web;
    using System.Web.Security;
    using System.Web.UI;
    using System.Web.UI.WebControls;
    using System.Web.UI.WebControls.WebParts;
    using System.Web.UI.HtmlControls;
    using System.Data.SqlClient;
    using System.Text.RegularExpressions;


    public partial class shopCart : System.Web.UI.Page
    {
        CommonClass ccObj = new CommonClass();
        DBClass dbObj = new DBClass();
        string strSql;
        DataTable dtTable;
        Hashtable hashCar;
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                if (Session["ShopCart"] == null)
                {
                    //如果没有购物,则给出相应信息,并隐藏按钮
                    this.labMessage.Text = "您还没有购物!";
                    this.labMessage.Visible = true;        //显示提示信息
                    this.lnkbtnCheck.Visible = false;      //隐藏“前往服务台”按钮
                    this.lnkbtnClear.Visible = false;      //隐藏“清空购物车”按钮
                    this.lnkbtnContinue.Visible = false;   //隐藏“继续购物”按钮

                }
                else
                {
                    hashCar = (Hashtable)Session["ShopCart"]; //获取其购物车
                    if (hashCar.Count == 0)
                    {
                        //如果没有购物,则给出相应信息,并隐藏按钮
                        this.labMessage.Text = "您购物车中没有商品!";
                        this.labMessage.Visible = true;        //显示提示信息
                        this.lnkbtnCheck.Visible = false;      //隐藏“前往服务台”按钮
                        this.lnkbtnClear.Visible = false;      //隐藏“清空购物车”按钮
                        this.lnkbtnContinue.Visible = false;   //隐藏“继续购物”按钮

                    }
                    else
                    {
                        //设置购物车内容的数据源
                        dtTable = new DataTable();
                        DataColumn column1 = new DataColumn("No");        //序号列
                        DataColumn column2 = new DataColumn("BookID");    //书籍ID代号
                        DataColumn column3 = new DataColumn("BookName");  //书籍名称
                        DataColumn column4 = new DataColumn("Num");       //数量
                        DataColumn column5 = new DataColumn("price");     //单价
                        DataColumn column6 = new DataColumn("totalPrice");//总价
                        dtTable.Columns.Add(column1);  //添加新列           
                        dtTable.Columns.Add(column2);
                        dtTable.Columns.Add(column3);
                        dtTable.Columns.Add(column4);
                        dtTable.Columns.Add(column5);
                        dtTable.Columns.Add(column6);
                        DataRow row;
                        //对数据表中每一行进行遍历,给每一行的新列赋值
                        //foreach (object key in hashCar.Keys)
                        //{
                        //    row = dtTable.NewRow();
                        //    row["BookID"] = key.ToString();
                        //    row["Num"] = hashCar[key].ToString();
                        //    dtTable.Rows.Add(row);
                        //}
                        foreach (DictionaryEntry hash in hashCar)
                        {
                            row = dtTable.NewRow();
                            row["BookID"] = hash.Key.ToString();
                            row["Num"] = hash.Value.ToString();
                            dtTable.Rows.Add(row);
                        }
                        //计算价格
                        DataTable dstable;
                        int i = 1;
                        float price;//商品单价
                        int count;  //商品数量
                        float totalPrice = 0; //商品总价格
                        foreach (DataRow drRow in dtTable.Rows)
                        {
                            strSql = "select BookName,HotPrice from tb_BookInfo where BookID=" + Convert.ToInt32(drRow["BookID"].ToString());
                            dstable = dbObj.GetDataSetStr(strSql, "tbGI");
                            drRow["No"] = i;//序号
                            drRow["BookName"] = dstable.Rows[0][0].ToString();//书籍名称
                            drRow["price"] = (dstable.Rows[0][1].ToString());//单价
                            price = float.Parse(dstable.Rows[0][1].ToString());//单价
                            count = Int32.Parse(drRow["Num"].ToString());
                            drRow["totalPrice"] = price * count; //总价
                            totalPrice += price * count; //计算合价
                            i++;
                        }
                        this.labTotalPrice.Text = "总价:" + totalPrice.ToString();  //显示所有商品的价格
                        this.gvShopCart.DataSource = dtTable.DefaultView;   //绑定GridView控件
                        this.gvShopCart.DataKeyNames = new string[] { "BookID" };
                        this.gvShopCart.DataBind();
                    }
                }
           
            }
          
        }
        public void bind()
        {
            if (Session["ShopCart"] == null)
            {
                //如果没有购物,则给出相应信息,并隐藏按钮
                this.labMessage.Text = "您还没有购物!";
                this.labMessage.Visible = true;        //显示提示信息
                this.lnkbtnCheck.Visible = false;      //隐藏“前往服务台”按钮
                this.lnkbtnClear.Visible = false;      //隐藏“清空购物车”按钮
                this.lnkbtnContinue.Visible = false;   //隐藏“继续购物”按钮
               
            }
            else
            {
                hashCar = (Hashtable)Session["ShopCart"]; //获取其购物车
                if (hashCar.Count == 0)
                {
                    //如果没有购物,则给出相应信息,并隐藏按钮
                    this.labMessage.Text = "您购物车中没有商品!";
                    this.labMessage.Visible = true;        //显示提示信息
                    this.lnkbtnCheck.Visible = false;      //隐藏“前往服务台”按钮
                    this.lnkbtnClear.Visible = false;      //隐藏“清空购物车”按钮
                    this.lnkbtnContinue.Visible = false;   //隐藏“继续购物”按钮
                  
                }
                else
                {
                    //设置购物车内容的数据源
                    dtTable = new DataTable();
                    DataColumn column1 = new DataColumn("No");        //序号列
                    DataColumn column2 = new DataColumn("BookID");    //书籍ID代号
                    DataColumn column3 = new DataColumn("BookName");  //书籍名称
                    DataColumn column4 = new DataColumn("Num");       //数量
                    DataColumn column5 = new DataColumn("price");     //单价
                    DataColumn column6 = new DataColumn("totalPrice");//总价
                    dtTable.Columns.Add(column1);  //添加新列           
                    dtTable.Columns.Add(column2);
                    dtTable.Columns.Add(column3);
                    dtTable.Columns.Add(column4);
                    dtTable.Columns.Add(column5);
                    dtTable.Columns.Add(column6);
                    DataRow row;
                    //对数据表中每一行进行遍历,给每一行的新列赋值
                    foreach (object key in hashCar.Keys)
                    {
                        row = dtTable.NewRow();
                        row["BookID"] = key.ToString();
                        row["Num"] = hashCar[key].ToString();
                        dtTable.Rows.Add(row);
                    }
                    //计算价格
                    DataTable dstable;
                    int i = 1;
                    float price;//商品单价
                    int count;  //商品数量
                    float totalPrice = 0; //商品总价格
                    foreach (DataRow drRow in dtTable.Rows)
                    {
                        strSql = "select BookName,HotPrice from tb_BookInfo where BookID=" + Convert.ToInt32(drRow["BookID"].ToString());
                        dstable = dbObj.GetDataSetStr(strSql, "tbGI");
                        drRow["No"] = i;//序号
                        drRow["BookName"] = dstable.Rows[0][0].ToString();//书籍名称
                        drRow["price"] = (dstable.Rows[0][1].ToString());//单价
                        price = float.Parse(dstable.Rows[0][1].ToString());//单价
                        count = Int32.Parse(drRow["Num"].ToString());
                        drRow["totalPrice"] = price * count; //总价
                        totalPrice += price * count; //计算合价
                        i++;
                    }
                    this.labTotalPrice.Text = "总价:" + totalPrice.ToString();  //显示所有商品的价格
                    this.gvShopCart.DataSource = dtTable.DefaultView;   //绑定GridView控件
                    this.gvShopCart.DataKeyNames=new string[] {"BookID"};
                    this.gvShopCart.DataBind();
                }
            }
               
       
       
        }
        protected void lnkbtnUpdate_Click(object sender, EventArgs e)
        {
            hashCar = (Hashtable)Session["ShopCart"];  //获取其购物车
            //使用foreach语句,遍历更新购物车中的商品数量
            foreach (GridViewRow gvr in this.gvShopCart.Rows)
            {
                TextBox otb = (TextBox)gvr.FindControl("txtNum"); //找到用来输入数量的TextBox控件
                int count = Int32.Parse(otb.Text);//获得用户输入的数量值
                string BookID = gvr.Cells[1].Text;//得到该商品的ID代
                hashCar[BookID] = count;//更新hashTable表
            }
            Session["ShopCart"] = hashCar;//更新购物车
            Response.Redirect("shopCart.aspx");
        }
        protected void lnkbtnDelete_Command(object sender, CommandEventArgs e)
        {
            hashCar = (Hashtable)Session["ShopCart"];//获取其购物车
            //从Hashtable表中,将指定的商品从购物车中移除,其中,删除按钮(lnkbtnDelete)的CommandArgument参数值为商品ID代号
            hashCar.Remove(e.CommandArgument);
            Session["ShopCart"] = hashCar; //更新购物车
            Response.Redirect("shopCart.aspx");
        }
        protected void lnkbtnClear_Click(object sender, EventArgs e)
        {
            Session["ShopCart"] =null;
            Response.Redirect("shopCart.aspx");
        }
        protected void lnkbtnContinue_Click(object sender, EventArgs e)
        {
            Response.Redirect("Default.aspx");
        }
        protected void lnkbtnCheck_Click(object sender, EventArgs e)
        {
            Response.Redirect("checkOut.aspx");
        }
        protected void gvShopCart_PageIndexChanging(object sender, GridViewPageEventArgs e)
        {
            gvShopCart.PageIndex = e.NewPageIndex;
            bind();

        }
        protected void txtNum_TextChanged(object sender, EventArgs e)
        {
            hashCar = (Hashtable)Session["ShopCart"];  //获取其购物车
            foreach (GridViewRow gvr in this.gvShopCart.Rows)
            {

                TextBox otb = (TextBox)gvr.FindControl("txtNum"); //找到用来输入数量的TextBox控件
                int count = Int32.Parse(otb.Text);//获得用户输入的数量值
                string BookID = gvr.Cells[1].Text;//得到该商品的ID代
                hashCar[BookID] = count;//更新hashTable表

            }
            Session["ShopCart"] = hashCar;//更新购物车
            bind();

        }

    //shopcart.aspx

                            <table cellSpacing="0" cellPadding="0" width="95%" align="center" border="0" style="FONT-SIZE: 9pt">
                                 <tr>
                                 <td align="center">
                                    <asp:Label ID="labMessage" runat="server" Visible="False"></asp:Label></td>
                                </tr>
                                <tr>
                                 <td align="left" height =30px>
                                    <asp:Label ID="labTotalPrice" runat="server" Text="0.00 " ></asp:Label>¥</td>
                                </tr>
                                <tr style =" font :9pt; font-family :宋体;"  valign =top >
                                <td align="left" style="height: 135px">
                               
                                 <asp:GridView ID="gvShopCart" DataKeyNames ="BookID"   runat="server"  AutoGenerateColumns="False"  AllowPaging="True" OnPageIndexChanging="gvShopCart_PageIndexChanging" >
                                     <Columns>
                                         <asp:BoundField DataField="No" HeaderText="序号" ReadOnly="True">
                                             <ItemStyle HorizontalAlign="Center" />
                                             <HeaderStyle HorizontalAlign="Center" />
                                         </asp:BoundField> 
                                          <asp:BoundField DataField="BookID" HeaderText="书籍ID" ReadOnly="True">
                                             <ItemStyle HorizontalAlign="Center" />
                                             <HeaderStyle HorizontalAlign="Center" />
                                         </asp:BoundField>                                   
                                         <asp:BoundField DataField="BookName" HeaderText="书籍名称" ReadOnly="True">
                                          <ItemStyle HorizontalAlign="Center" />
                                          <HeaderStyle HorizontalAlign="Center" />
                                         </asp:BoundField> 
                                         <asp:TemplateField HeaderText="数量">
                                        <ItemTemplate >
                                           <asp:TextBox ID="txtNum" runat="server" Text =<%#Eval("Num") %> Width =60px  OnTextChanged="txtNum_TextChanged"></asp:TextBox>
                                           <asp:RegularExpressionValidator
                                    ID="RegularExpressionValidator1" runat="server" ControlToValidate="txtNum"
                                    ErrorMessage="×" ValidationExpression="^\+?[1-9][0-9]*$"></asp:RegularExpressionValidator>
                                    </ItemTemplate>
                                    </asp:TemplateField>
                                      
                                         <asp:TemplateField HeaderText =单价>
                                             <HeaderStyle HorizontalAlign=Center />
                                             <ItemStyle HorizontalAlign =Center />
                                             <ItemTemplate >
                                                <%#Eval("price")%>¥
                                             </ItemTemplate>   
                                         </asp:TemplateField>
                                        <asp:TemplateField HeaderText =总价>
                                             <HeaderStyle HorizontalAlign=Center />
                                             <ItemStyle HorizontalAlign =Center />
                                             <ItemTemplate >
                                                <%#Eval("totalPrice")%>¥
                                             </ItemTemplate>   
                                         </asp:TemplateField>
                                         <asp:TemplateField>
                                             <HeaderStyle HorizontalAlign=Center />
                                             <ItemStyle HorizontalAlign =Center />
                                             <ItemTemplate >
                                                 <asp:LinkButton ID="lnkbtnDelete" runat="server" CommandArgument ='<%#Eval("BookID") %>' OnCommand ="lnkbtnDelete_Command">删除</asp:LinkButton>
                                             </ItemTemplate>   
                                         </asp:TemplateField>
                                        
                                     </Columns>
                                    </asp:GridView>
                                </td>
                                </tr>
                                <tr align =left valign =top  >
                                    <td align="center"  >
                                        <asp:LinkButton ID="lnkbtnUpdate" runat="server" OnClick="lnkbtnUpdate_Click">更新购物车</asp:LinkButton>
                                        &nbsp;<asp:LinkButton ID="lnkbtnClear" runat="server" OnClick="lnkbtnClear_Click" >清空购物车</asp:LinkButton>
                                        <asp:LinkButton ID="lnkbtnContinue" runat="server" OnClick="lnkbtnContinue_Click" >继续购物</asp:LinkButton> 
                                        <asp:LinkButton ID="lnkbtnCheck" runat="server" OnClick="lnkbtnCheck_Click" >前往服务台</asp:LinkButton>
                                        </td>
                                </tr>
                                <tr>
                                <td align="left"  >
                                    <br />
                                    &nbsp;<li>如果要修改商品数量,请单击“更新购物车”按钮 &nbsp;&nbsp;&nbsp;</li>&nbsp;<li>如果要取消某个商品,请单击“删除”
                                <br />
                                </li>
                                </td>
                                </tr>
                            </table>

    Default.aspx.cs //添加物品到购物车代码

        protected void dlDiscount_ItemCommand(object source, DataListCommandEventArgs e)
        {
            if (e.CommandName == "detailSee")
            {
                AddressBack(e);
            }
            else if (e.CommandName == "buy")
            {
                AddShopCart(e);
            }

        }
        protected void dlHot_ItemCommand(object source, DataListCommandEventArgs e)
        {
            if (e.CommandName == "detailSee")
            {
                AddressBack(e);
            }
            else if (e.CommandName == "buy")
            {
                AddShopCart(e);
            }

        }
        /// <summary>
        /// 向购物车中添加新商品
        /// </summary>
        /// <param name="e">
        /// 获取或设置可选参数,
        /// 该参数与关联的 CommandName
        /// 一起被传递到 Command 事件。
        /// </param>
        public void AddShopCart(DataListCommandEventArgs e)
        {
            Hashtable hashCar;
            if (Session["ShopCart"] == null)
            {
                //如果用户没有分配购物车
                hashCar = new Hashtable();         //新生成一个
                hashCar.Add(e.CommandArgument, 1); //添加一个商品
                Session["ShopCart"] = hashCar;     //分配给用户
            }
            else
            {
                //用户已经有购物车
                hashCar = (Hashtable)Session["ShopCart"];//得到购物车的hash表
                if (hashCar.Contains(e.CommandArgument))//购物车中已有此商品,商品数量加1
                {
                    int count = Convert.ToInt32(hashCar[e.CommandArgument].ToString());//得到该商品的数量
                    hashCar[e.CommandArgument] = (count + 1);//商品数量加1
                }
                else
                    hashCar.Add(e.CommandArgument, 1);//如果没有此商品,则新添加一个项
            }

        }

    this.ClientScript.RegisterStartupScript(this.GetType(),"",<script>alert("商品添加成功!")</script>);

    另附上一关于session实现购物车的视频讲解地址:http://www.itzcn.com/video-vid-251-spid-19.html

    HashTable实现购物车,

      先前我们的购物车使用的是数据库方式实现,每次购物都要进行数据库操作,很影响效率。现在我们采用HashTable和Session来实现购物车,这样便节省了数据库的操作,大大的提高效率

    1 private void DataGrid1_ItemCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)//假设前面购买命令是一个命令名为buy的LinkButton
       2 {//关键,建立和加如购物车
       3 string pid=this.DataGrid1.DataKeys[e.Item.ItemIndex].ToString();//取出编号
       4 if(e.CommandName=="buy")//如果命令名是 buy,说明是购买
       5 {
    6 if(Session["bus"]==null)//先就得检查购物车是否存在,如果不存在,就建立
       7 {
    8 System.Collections.Hashtable ht=new Hashtable();//先建立一个哈希表
       9 ht.Add(pid,1);//哈希表中的两个列,一个key,一个value ,key放编号,value放购买数量好了,预设置为1
      10 Session["bus"]=ht;//将哈希表赋值给Session对象
      11 }
    12 else//如果存在的话
      13 {
    14 Hashtable ht=(Hashtable)Session["bus"];//使用强制类型转换,再将Session["bus"]赋值给哈希表对象 ht
      15 if(ht[pid]==null)//如果哈希表中对应的ID没有,
      16 {
    17 ht[pid]=1;//那就直接给他设为 1
      18 }
    19 else//如果已经有对应的ID
      20 {
    21 ht[pid]=(int)ht[pid]+1;//那么就把原来的取出来再加上 1
      22 }
    23 Session["bus"]=ht;//最后再更新Session 对象
      24 }
    25 }
    26
    27 }

      而读取的方法如下:

    this.DataList1.DataSource=(Hashtable)Session["bus"];
    this.DataList1.DataBind();
    1private void LinkButton1_Click(object sender, System.EventArgs e)
    2 {
    3
    4 foreach(DataListItem dl in this.DataList1.Items)//遍历集合
    5 {
    6 TextBox tb=(TextBox)dl.FindControl("TextBox1");//找到文本框
    7 int newpid=Convert.ToInt32(tb.Text.ToString());//查出文本框里面的值
    8
    9 Label label1=(Label)dl.FindControl("key");//找到装载哈希表key字段的那个控件
    10 string pid=label1.Text.ToString();//把他的值拿出来
    11
    12 Hashtable ht=(Hashtable)Session["bus"];//把session["bus"]对象赋值给哈希表 ht
    13 int oldpid=(int)ht[pid];//求得原来的数量
    14
    15 if(newpid!=oldpid)//如果文本框里的值不等于原来的数量,就用新的更换到哈希表中的值
    16 {
    17 ht[pid]=newpid;
    18 }
    19 Session["bus"]=ht;//最后再更新Session 对象
    20 }
    21 }

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  • 原文地址:https://www.cnblogs.com/lushuicongsheng/p/1877255.html
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