Question

问题是，当同一项目再次添加到购物车时，它会显示相同产品的相同记录两次，这里我希望当我按下添加到购物车按钮两次或三次然后它应该是增量数量同一个项目。

protected void AddToCartButton_Click(object sender, EventArgs e)
{
    if (con.State == ConnectionState.Open)
    {
        con.Close();
    }
    con.Open();
    SqlCommand cmd = con.CreateCommand();
    cmd.CommandType = CommandType.Text;
    book_id = Convert.ToInt32(Request.QueryString["book_id"].ToString());
    cmd.CommandText = "select * from Book where book_id = " + book_id + "";
    cmd.ExecuteNonQuery();
    DataTable dt = new DataTable();
    SqlDataAdapter sda = new SqlDataAdapter(cmd);
    sda.Fill(dt);
    foreach (DataRow dr in dt.Rows)
    {                 
        //book_id =Convert.ToInt32(dr["book_id"]);
        title = dr["title"].ToString();
        //quantity = dr["quantity"].ToString();
        quantity = QuantityTxt.Text;
        price = dr["price"].ToString();
    }
    //Restrict User to enter some quantity that he wants...
    if(Convert.ToInt32(QuantityTxt.Text)>Convert.ToInt32(quantity))
    {
        ErrorMsglbl.Text = "Please Enter Lower Quantity";
    }
    else
    {
        ErrorMsglbl.Text = "";
    }
    // Creating Cookies to store the value and then i will assign to data table... 

    if (Request.Cookies["ShoppingCart"] == null)
    {
        Response.Cookies["ShoppingCart"].Value = book_id.ToString() + "," + title.ToString() + "," + quantity.ToString() + "," + price.ToString();
        Response.Cookies["ShoppingCart"].Expires = DateTime.Now.AddDays(1);
    }
    else
    {
        Response.Cookies["ShoppingCart"].Value = Request.Cookies["ShoppingCart"].Value + "|" + book_id.ToString() + "," + title.ToString() + "," + quantity.ToString() + "," + price.ToString();
        Response.Cookies["ShoppingCart"].Expires = DateTime.Now.AddDays(1);
    }

    Response.Redirect("BookDetails.aspx?book_id="+book_id.ToString()+"&Cat_ID="+ViewState["cat"]+"");

}// End Add To Cart Button...

Answer 1

问题出在其他块

 Response.Cookies["ShoppingCart"].Value = Request.Cookies["ShoppingCart"].Value + 
"|" + book_id.ToString() + "," + title.ToString() + 
"," + quantity.ToString() + "," + price.ToString();

您可以在此处将以前的Cookie值与新内容一起分配给新Cookie。对于例如如果你有＆＃34; 1，Shoe，1,25＆＃34;在你的cookie中再次将相同的产品添加到购物车中，你会得到类似＆＃34; 1，Shoe，1,25 |的东西1，鞋子，1,25＆＃34;。

这个问题可以通过多种方法解决

拆分您的Cookie并查看book_id值
使用对象存储购物车项目并将其保存在会话中。

接近第一

String[] carts = Request.Cookies["ShoppingCart"].Value.Split("|")
bool bookIdExists = false;
foreach(string cartDetail in carts)
{
  string  bookId = cartDetail.Split(",")[0];
  if(bookId == newBookId)
  {
    bookIdExists = true;
  }
}
if(!bookIDExists)
{
  //Add your new item to Cookie
}

第二种方法

public Class Cart
{
  public int BookId {get; set;}
  public string Title {get; set;}
  public int Qty {get; set;}
  public decimal Price {get; set}
}

List<Cart> carts =Session["Cart"]==null? new List<Cart>(): Session["Cart"] as List<Cart>;
var existingCart = carts.Where(x=> x.BookId==newBookId).FirstOrDefault();
if(existingCart==null)
{
  Cart c= new Cart {
  BookId = newBookId,
  Title =newTitle,
  Qty = newQty,
  Price =newPrice
};
 carts.Add(c);
 Session["Cart"] = carts;
}

您可以采用更好的方法来解决问题。

但使用cookie来存储您的购物车详情是很糟糕的。

购物车显示记录两次

1 个答案: