How to Sort a List<T> by a property in the object

I have a class called `Order` which has properties such as `OrderId`, `OrderDate`, `Quantity`, and `Total`. I have a list of this `Order` class:

```c#
List<Order> objListOrder = new List<Order>();
GetOrderList(objListOrder); // fill list of orders
```

I want to sort the list based on one property of the `Order` object; for example, either by `OrderDate` or `OrderID`.

How can I do this in C#?

Using LINQ

objListOrder = GetOrderList()
.OrderBy(o => o.OrderDate)
.ToList();

objListOrder = GetOrderList()
.OrderBy(o => o.OrderId)
.ToList();

Make use of LiNQ [`OrderBy`][1]

List<Order> objListOrder=new List<Order> ();
objListOrder=GetOrderList().OrderBy(o=>o.orderid).ToList();


[1]:

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To do this without LINQ on .Net2.0:

List<Order> objListOrder = GetOrderList();
objListOrder.Sort(
delegate(Order p1, Order p2)
{
return p1.OrderDate.CompareTo(p2.OrderDate);
}
);

If you're on .Net3.0, then LukeH's [answer][1] is what you're after.

To sort on multiple properties, you can still do it within a delegate. For example:

orderList.Sort(
delegate(Order p1, Order p2)
{
int compareDate = p1.Date.CompareTo(p2.Date);
if (compareDate == 0)
{
return p2.OrderID.CompareTo(p1.OrderID);
}
return compareDate;
}
);

This would give you **ascending** dates with **descending** orderIds.

However, I wouldn't recommend sticking delegates as it will mean lots of places without code re-use. You should implement an `IComparer` and just pass that through to your `Sort` method. See [here][2].


public class MyOrderingClass : IComparer<Order>
{
public int Compare(Order x, Order y)
{
int compareDate = x.Date.CompareTo(y.Date);
if (compareDate == 0)
{
return x.OrderID.CompareTo(y.OrderID);
}
return compareDate;
}
}

And then to use this IComparer class, just instantiate it and pass it to your Sort method:

IComparer<Order> comparer = new MyOrderingClass();
orderList.Sort(comparer);


[1]:

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[2]:

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//Get data from database, then sort list by staff name:

List<StaffMember> staffList = staffHandler.GetStaffMembers();

var sortedList = from staffmember in staffList
orderby staffmember.Name ascending
select staffmember;

// Totally generic sorting for use with a gridview

public List<T> Sort_List<T>(string sortDirection, string sortExpression, List<T> data)
{

List<T> data_sorted = new List<T>();

if (sortDirection == "Ascending")
{
data_sorted = (from n in data
orderby GetDynamicSortProperty(n, sortExpression) ascending
select n).ToList();
}
else if (sortDirection == "Descending")
{
data_sorted = (from n in data
orderby GetDynamicSortProperty(n, sortExpression) descending
select n).ToList();

}

return data_sorted;

}

public object GetDynamicSortProperty(object item, string propName)
{
//Use reflection to get order type
return item.GetType().GetProperty(propName).GetValue(item, null);
}