[网络收集]利用Session对象实现购物车
作者：互联网
来自森大科技官方博客
http://www.cnsendblog.com/index.php/?p=338
GPS平台、网站建设、软件开发、系统运维，找森大网络科技！
http://cnsendnet.taobao.com
//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>);
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 }
来自森大科技官方博客
http://www.cnsendblog.com/index.php/?p=338
GPS平台、网站建设、软件开发、系统运维，找森大网络科技！
http://cnsendnet.taobao.com
标签：收集,Session,DataColumn,hashCar,购物车,dtTable,ToString 来源： https://www.cnblogs.com/cnsend/p/12230917.html