c#利用Session对象实现购物车的方法示例

本文实现了c# Session对象实现购物车的方法，分享给大家，也给自己留个笔记：

//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>
                   <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 />
                 <li>如果要修改商品数量，请单击“更新购物车”按钮    </li> <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>);

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

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
{//关键，建立和加如购物车
string pid=this.DataGrid1.DataKeys[e.Item.ItemIndex].ToString();//取出编号
if(e.CommandName=="buy")//如果命令名是 buy，说明是购买
{
if(Session["bus"]==null)//先就得检查购物车是否存在,如果不存在,就建立
{
System.Collections.Hashtable ht=new Hashtable();//先建立一个哈希表
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
Session["bus"]=ht;//将哈希表赋值给Session对象
}
else//如果存在的话
{
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
if(ht[pid]==null)//如果哈希表中对应的ＩＤ没有，
{
ht[pid]=1;//那就直接给他设为　１
}
else//如果已经有对应的ＩＤ
{
ht[pid]=(int)ht[pid]+1;//那么就把原来的取出来再加上　１
}
Session["bus"]=ht;//最后再更新Session 对象
}
}
 }

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)
{
 foreach(DataListItem dl in this.DataList1.Items)//遍历集合
{
TextBox tb=(TextBox)dl.FindControl("TextBox1");//找到文本框
int newpid=Convert.ToInt32(tb.Text.ToString());//查出文本框里面的值
 Label label1=(Label)dl.FindControl("key");//找到装载哈希表key字段的那个控件
string pid=label1.Text.ToString();//把他的值拿出来
 Hashtable ht=(Hashtable)Session["bus"];//把session["bus"]对象赋值给哈希表 ht
int oldpid=(int)ht[pid];//求得原来的数量
 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
{
ht[pid]=newpid;
}
Session["bus"]=ht;//最后再更新Session 对象
}
}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持我们。