C# Enumerable ThenByDescending(IOrderedEnumerable, Func, IComparer)
Description
Performs a subsequent ordering of the elements in a sequence in descending order by using a specified comparer.
Syntax
public static IOrderedEnumerable<TSource> ThenByDescending<TSource, TKey>(
this IOrderedEnumerable<TSource> source,
Func<TSource, TKey> keySelector,
IComparer<TKey> comparer/*from w ww . j a v a 2 s .com*/
)
Parameters
TSource- The type of the elements of source.TKey- The type of the key returned by keySelector.source- An IOrderedEnumerablethat contains elements to sort. keySelector- A function to extract a key from each element.comparer- An IComparerto compare keys.
Example
The following code example demonstrates how to use ThenByDescending to perform a secondary ordering of the elements in a sequence in descending order by using a custom comparer.
/*w w w.j av a2 s . com*/
using System;
using System.Linq;
using System.Collections.Generic;
public class MainClass{
public static void Main(String[] argv){
string[] fruits = { "apPLe", "orange", "BAnana", "ORANGE", "apPLE" };
IEnumerable<string> query = fruits.OrderBy(fruit => fruit.Length)
.ThenByDescending(fruit => fruit, new CaseInsensitiveComparer());
foreach (string fruit in query)
{
Console.WriteLine(fruit);
}
}
}
public class CaseInsensitiveComparer : IComparer<string>{
public int Compare(string x, string y)
{
return string.Compare(x, y, true);
}
}
The code above generates the following result.
