How to Sort a List by a property in the object

Question

I have a class called Order which has properties such as OrderId, OrderDate, Quantity, and Total. I have a l

Answer 1

Based on GenericTypeTea's Comparer :
we can obtain more flexibility by adding sorting flags :

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

            if (OrderIdDescending) {  
                compareOrderId = -compareOrderId;  
            }  
            return compareOrderId;  
        }  

        if (DateDescending) {  
            compareDate = -compareDate;  
        }  
        return compareDate;  
    }  

    public bool DateDescending { get; set; }  
    public bool OrderIdDescending { get; set; }  
}  

In this scenario, you must instantiate it as MyOrderingClass explicitly( rather then IComparer )
in order to set its sorting properties :

MyOrderingClass comparer = new MyOrderingClass();  
comparer.DateDescending = ...;  
comparer.OrderIdDescending = ...;  
orderList.Sort(comparer);