private void BindCartList()
{
if (Session[CartTableName] == null)
{
// 如果 Session 变量不存在，创建存储数据的表结构
ShoppingCartDataTable = new DataTable();
ShoppingCartDataTable.Columns.Add(new DataColumn("ProductID", typeof(int)));
ShoppingCartDataTable.Columns.Add(new DataColumn("ProductName", typeof(string)));
ShoppingCartDataTable.Columns.Add(new DataColumn("UnitPrice", typeof(decimal)));
ShoppingCartDataTable.Columns.Add(new DataColumn("Quantity", typeof(int)));
ShoppingCartDataTable.Columns.Add(new DataColumn("ItemTotal", typeof(decimal)));
Session[CartTableName] = ShoppingCartDataTable;
}
else
{
// 如果 Session 存在，则直接读取
ShoppingCartDataTable = (DataTable)Session[CartTableName];
}
// 如果用户传递的参数 ProductID 不为 null，则表示选中一件商品即将要添加进购物车
if (Request.QueryString["ProductID"] != null)
{
string ProductID = Request.QueryString["ProductID"];
// 先判断购物车中是否已经存在该商品
Boolean IsExist = false;
foreach (DataRow dr in ShoppingCartDataTable.Rows)
{
if (dr["ProductID"].ToString() == ProductID)
{
IsExist = true;
break;
}
}
if (IsExist)
{
// 如果购物车中存在该商品，则提示客户：该商品不会被重复添加到购物车
ScriptManager.RegisterStartupScript(this, typeof(Page), "alertExist", string.Format("alert('您选择的商品（编号：{0}）已存在于购物车中，您可以在购物车中更改您所需要购买的商品数量。')", ProductID), true);
}
else // 如果购物车中不存在该商品，则添加到购物车
{
//DataTable NewShoppingCartDataTable = DataBaseClass.GetDataTable(string.Format("Select * From PRODUCT_INFO Where ProductID='{0}'", ProductID.ToString()));
DataTable NewShoppingCartDataTable = Product.GetProduct(ProductID);
decimal UnitPrice = Convert.ToDecimal(NewShoppingCartDataTable.Rows[0]["UnitPrice"]);
int Quantity = 1;
DataRow NewShoppingCartDataRow = ShoppingCartDataTable.NewRow();
NewShoppingCartDataRow["ProductID"] = Convert.ToInt32(ProductID.ToString());
NewShoppingCartDataRow["ProductName"] = NewShoppingCartDataTable.Rows[0]["ProductName"].ToString();
NewShoppingCartDataRow["UnitPrice"] = UnitPrice;
NewShoppingCartDataRow["Quantity"] = Quantity;
NewShoppingCartDataRow["ItemTotal"] = UnitPrice * Quantity;
ShoppingCartDataTable.Rows.Add(NewShoppingCartDataRow);
}
}
// 以 CartDataTable 作为 CartGridView 控件的数据源
ShoppingCartGridView.DataSource = ShoppingCartDataTable;
// 绑定
ShoppingCartGridView.DataBind();
Session[CartTableName] = ShoppingCartDataTable;
}
private void BindData()
{
ShoppingCartGridView.DataSource = Session[CartTableName];
ShoppingCartGridView.DataBind();
}
