///用户点击购买食物，处理订单（购物车）
protected void FoodListView_OnItemCommand(object sender, DataListCommandEventArgs e)
{
//未登录
if (Session["UserName"] == null)
{
Page.Response.Write("<script>alert('请登录!')</script>");
return;
}
//从Session获取userId，从ItemIndex获取foodId，调用逻辑层的购物车
//从DataList中选择，得到foodid
int foodselectindex = FoodListView.SelectedIndex = e.Item.ItemIndex;
int foodid = foodlist.ElementAt(foodselectindex).FoodId;
int userId = Convert.ToInt32(Session["UserId"].ToString());
//调用逻辑层实现加入购物车
OrderControl oc = new OrderControl();
oc.ProductCarAddFood(userId, foodid);
Response.Write("<script language=javascript>window.location.href='index.aspx';</script>");
}
