linq-to-objects

I have a list of orders . I want to select orders based on a set of order statuses. So essentially select orders where order.StatusCode in ("A", "B", "C") // Filter the orders based on the order status var filteredOrders = from order in orders.Order where order.StatusCode.????????("A", "B", "C") select order; Your status-codes are also a collection, so use Contains : var allowedStatus = new[]{ "A", "B", "C" }; var filteredOrders = orders.Order.Where(o => allowedStatus.Contains(o.StatusCode)); or in query syntax: var filteredOrders = from order in orders.Order where allowedStatus.Contains(order

This question already has an answer here: How to perform .Max() on a property of all objects in a collection and return the object with maximum value [duplicate] 9 answers How to use LINQ to select object with minimum or maximum property value 12 answers If I have a class that looks like: public class Item { public int ClientID { get; set; } public int ID { get; set; } } And a collection of those items... List<Item> items = getItems(); How can I use LINQ to return the single "Item" object which has the highest ID? If I do something like: items.Select(i => i.ID).Max(); I'll only get the highest

I have a list<message> that contains properties of type Guid and DateTime (as well as other properties). I would like to get rid of all of the items in that list where the Guid and DateTime are the same (except one). There will be times when those two properties will be the same as other items in the list, but the other properties will be different, so I can't just use .Distinct() List<Message> messages = GetList(); //The list now contains many objects, it is ordered by the DateTime property messages = from p in messages.Distinct( what goes here? ); This is what I have right now, but it seems

There was a library of dynamic LINQ extensions methods released as a sample with Visual Studio 2008 . I'd like to extend it with a join method. The code below fails with a parameter miss match exception at run time. Where is the problem? public static IQueryable Join(this IQueryable outer, IEnumerable inner, string outerSelector, string innerSelector, string resultsSelector, params object[] values) { if (inner == null) throw new ArgumentNullException("inner"); if (outerSelector == null) throw new ArgumentNullException("outerSelector"); if (innerSelector == null) throw new ArgumentNullException

I want to display a customer's accounting history in a DataGridView and I want to have a column that displays the running total for their balance. The old way I did this was by getting the data, looping through the data, and adding rows to the DataGridView one-by-one and calculating the running total at that time. Lame. I would much rather use LINQ to SQL, or LINQ if not possible with LINQ to SQL, to figure out the running totals so I can just set DataGridView.DataSource to my data. This is a super-simplified example of what I'm shooting for. Say I have the following class. class Item { public