//用戶(hù)購(gòu)買(mǎi)商品時(shí)if (e.CommandName.ToLower() == "buy") { //判斷用戶(hù)購(gòu)物車(chē)是否為空 如果為空則分配一個(gè) Hashtable table; if (Session["car"] == null) {  table = new Hashtable(); } else {  //用戶(hù)購(gòu)物車(chē)己存在 則取出數(shù)據(jù)  table = Session["car"] as Hashtable; } //如果用戶(hù)購(gòu)物車(chē)中不包括該商品信息 則添加一個(gè)新商品 if (!table.Contains(e.CommandArgument)) {  table.Add(e.CommandArgument, 1);//添加一個(gè)新商品 數(shù)量為1 } else  {  //如果購(gòu)物車(chē)己存在該商品信息 則將該商品的數(shù)量加1 根據(jù)HashTable的鍵獲取相對(duì)應(yīng)的值  int count = Convert.ToInt32(table[e.CommandArgument].ToString());  //給該商品數(shù)量加上1  table[e.CommandArgument] = (count + 1); } //保存商品信息 Session["car"] = table; Response.Redirect("shoppingcar.aspx");}//商品信息列表private void shoplist(){  Hashtable table;  if (Session["car"] == null)  {   table = new Hashtable();  }  else  {   table = Session["car"] as Hashtable;  }  if (table.Count == 0)  {   Image13.Visible = true;   Msg.Visible = true;   Msg.Text = "<b style="color:red" mce_style="color:red">您還沒(méi)有購(gòu)物呢？趕快購(gòu)物吧!</b>";  }  string[] Arrkey = new string[table.Count];  int[] ArrVal = new int[table.Count];  table.Keys.CopyTo(Arrkey, 0);  table.Values.CopyTo(ArrVal, 0);  //定義字符串 形成 ('1,2,3')  string Products = "('";  int k = 0;  for (int j = 0; j < Arrkey.Length; j++)  {   if(k>0)Products += "','"; k++;   Products += Arrkey.GetValue(j).ToString();  }  Products += "')";  DataSet ds = productbll.GetInfoByWhere(" pid in " + Products);  DataTable Table1 = new DataTable();  Table1 = ds.Tables[0];  Table1.Columns.Add(new DataColumn("shuliang", System.Type.GetType("System.Int32")));  //得到pid的值 并將它設(shè)置為T(mén)able1的主鍵  DataColumn[] keys = { Table1.Columns["pid"]};  Table1.PrimaryKey = keys;  foreach (string key in table.Keys)  {   Table1.Rows.Find(key)["shuliang"] = table[key];//根據(jù)鍵獲取值 商品的數(shù)量  }  Table1.Columns.Add(new DataColumn("zongjia", System.Type.GetType("System.Double"), "hotprice*shuliang"));  for (int n = 0; n < Table1.Rows.Count; n++)   {   tPrice +=Convert.ToDouble(Table1.Rows[n]["zongjia"]);  }  Label1.Text = tPrice.ToString();  Session["total"] = Label1.Text.ToString();  MyGrid.DataSource = Table1.DefaultView;  MyGrid.DataBind();}#region 從購(gòu)物車(chē)中刪除一條商品信息protected void MyGrid_RowCommand(object sender, GridViewCommandEventArgs e){  Hashtable table;  if (Session["car"] == null)  {   table = new Hashtable();  }  else  {   table = Session["car"] as Hashtable;  }  //如果點(diǎn)擊刪除按鈕 則從購(gòu)物車(chē)中移除該商品信息  if (e.CommandName.ToLower() == "delete")  {   if (table.ContainsKey(e.CommandArgument))   {    //從HashTable中移除該商品的信息(商品編號(hào)) 鍵:為商品編號(hào) 值為:商品數(shù)量    table.Remove(e.CommandArgument);   }   Msg.Text = (string)e.CommandArgument;  }  Session["car"] = table;  //調(diào)用方法  shoplist();}#endregion