C# 4 and .NET 4

246 ❘ ChaPTer 10 cOllectiOns
}
}
documentList.RemoveFirst();
return doc;
In the Main() method, the PriorityDocumentManager is used to demonstrate its functionality.
Eight new documents with different priorities are added to the linked list, and then the complete list
is displayed:
static void Main()
{
PriorityDocumentManager pdm = new PriorityDocumentManager();
pdm.AddDocument(new Document("one", "Sample", 8));
pdm.AddDocument(new Document("two", "Sample", 3));
pdm.AddDocument(new Document("three", "Sample", 4));
pdm.AddDocument(new Document("four", "Sample", 8));
pdm.AddDocument(new Document("five", "Sample", 1));
pdm.AddDocument(new Document("six", "Sample", 9));
pdm.AddDocument(new Document("seven", "Sample", 1));
pdm.AddDocument(new Document("eight", "Sample", 1));
}
pdm.DisplayAllNodes();
code snippet LinkedListSample/Program.cs
With the processed result, you can see that the documents are sorted fi rst by the priority and second by
when the document was added:
priority: 9, title six
priority: 8, title one
priority: 8, title four
priority: 4, title three
priority: 3, title two
priority: 1, title five
priority: 1, title seven
priority: 1, title eight
sorTed lisT
If the collection you need should be sorted based on a key, you can use SortedList < TKey, TValue > .
This class sorts the elements based on a key. Not only can you use any type for the value, but also for
the key.
The example creates a sorted list where both the key and the value are of type string . The default constructor
creates an empty list, and then two books are added with the Add() method. With overloaded constructors,
you can defi ne the capacity of the list and also pass an object that implements the interface IComparer < TKey > ,
which is used to sort the elements in the list.
The fi rst parameter of the Add() method is the key (the book title); the second parameter is the value (the
ISBN number). Instead of using the Add() method, you can use the indexer to add elements to the list.
The indexer requires the key as index parameter. If a key already exists, the Add() method throws an
exception of type ArgumentException . If the same key is used with the indexer, the new value replaces
the old value.
SortedList < TKey, TValue > allows only one value per key. If you need multiple values
per key you can use Lookup < TKey , TElement > .
www.it-ebooks.info