Asp.Net MVC - Rob Conery's LazyList - Count() or Count
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by Adam
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Published on 2009-02-17T20:38:12Z
Indexed on
2010/04/22
13:43 UTC
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I'm trying to create an html table for order logs for customers. A customer is defined as (I've left out a lot of stuff):
public class Customer
{
public LazyList<Order> Orders { get; set; }
}
The LazyList is set when fetching a Customer:
public Customer GetCustomer(int custID)
{
Customer c = ...
c.Orders = new LazyList<Order>(_repository.GetOrders().ByOrderID(custID));
return c;
}
The order log model:
public class OrderLogTableModel
{
public OrderLogTableModel(LazyList<Order> orders)
{
Orders = orders;
Page = 0;
PageSize = 25;
}
public LazyList<Order> Orders { get; set; }
public int Page { get; set; }
public int PageSize { get; set; }
}
and I pass in the customer.Orders after loading a customer. Now the log i'm trying to make, looks something like:
<table>
<tbody>
<%
int rowCount = ViewData.Model.Orders.Count();
int innerRows = rowCount - (ViewData.Model.Page * ViewData.Model.PageSize);
foreach (Order order in ViewData.Model.Orders.OrderByDescending(x => x.StartDateTime)
.Take(innerRows).OrderBy(x => x.StartDateTime)
.Take(ViewData.Model.PageSize))
{
%>
<tr>
<td>
<%= order.ID %>
</td>
</tr>
<%
}
%>
</tbody>
</table>
Which works fine. But the problem is evaluating ViewData.Model.Orders.Count() literally takes about 10 minutes.
I've tried with the ViewData.Model.Orders.Count property instead, and the results are the same - takes forever.
I've also tried calling _repository.GetOrders().ByCustomerID(custID).Count() directly from the view and that executes perfectly within a few ms.
Can anybody see any reason why using the LazyList to get a simple count would take so long? It seems like its trying to iterate through the list when getting a simple count.
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