2007.12.19, Honda, Create. .NET collection objects summary
2008.11.29, Honda, Update

□ Generic types and collection types
優先使用Generic類別. 
優點: 1.type safety. 2.效率佳, 不需box/unbox物件.

Generic			nongeneric		Description
------------------------------- ----------------------- ---------------------------------------------	
List			ArrayList		List of typed-object/List of object.				
Dictionary		Hashtable		(Typed and Keyed) list of type-object/ Keyed object of list object.
Collection		CollectionBase		List of typed-object/Abstract version for derived.
ReadOnlyCollection	ReadOnlyCollectionBase
Queue			Queue (Same name)
SortedList		SortedList (Same name)
Stack			Stack (Same name)
LinkedList		none
SortedDictionary	none
KeyedCollection		none			Keyed list of typed object with the key inside.			
			StringCollection	List of string
			StringDictionary	Key

□ My catetory
Item			Generic	Description/Fragment
----------------------- -------	---------------------------------------------------------------------------------
List			Y	List of typed object		
	List<string> dinosaurs = new List<string>();

ArrayList		N	List of object
	ArrayList myAL = new ArrayList();
----------------------- -------	---------------------------------------------------------------------------------
Dictionary		Y	(Typed and Keyed) list of type-object
				Key重複時會Exception.
	Dictionary<string, string> openWith = new Dictionary<string, string>();
	openWith.Add(sKey, sValue);	// sKey已存在時, 新增會Exception.
        openWith[sKey] = sValue;	// sKey不存在時, 修改會新增一筆sKey
        sValue = openWith[sKey]);	// sKey不存在時, 讀取會Exception.
	if (openWith.TryGetValue(sKey, out value))	// 避開exception,讀取value
	if (!openWith.ContainsKey(sKey))		// 檢查sKey存在否
	foreach( KeyValuePair<string, string> kvp in openWith ) // 迴圈利用generic-type KeyValuePair
	{
		Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value);
	}

Hashtable		N	Keyed object list of object
	Hashtable openWith = new Hashtable();
        openWith.Add(oKey, oValue);		// oKey已存在時, 新增會exception. oKey, oValue必須實作ToString().
	openWith[oKey] = oValue;		// oKey不存在時會自動新增sKey
        if (!openWith.ContainsKey(oKey))	// 檢查oKey存在否
	foreach( DictionaryEntry de in openWith )	// 迴圈利用DictionaryEntry object.
	{
	        Console.WriteLine("Key = {0}, Value = {1}", de.Key, de.Value);
	}

----------------------- -------	---------------------------------------------------------------------------------
Collection		Y	List of typed object
	Collection<string> dinosaurs = new Collection<string>();

CollectionBase		N	List of typed object. Abstract version for derived.
	public class Int16Collection : CollectionBase  {...

----------------------- -------	---------------------------------------------------------------------------------
ReadOnlyCollection	Y	
ReadOnlyCollectionBase	N
----------------------- -------	---------------------------------------------------------------------------------
Queue			Y
Queue			N
----------------------- -------	---------------------------------------------------------------------------------
SortedList		Y
----------------------- -------	---------------------------------------------------------------------------------
Stack			Y
----------------------- -------	---------------------------------------------------------------------------------
LinkedList		Y
----------------------- -------	---------------------------------------------------------------------------------
SortedDictionary	Y
----------------------- -------	---------------------------------------------------------------------------------
KeyedCollection		Y	Keyed list of typed object with the key inside. 
				To store objects that contain their own keys. 
				必須覆寫 int GetKeyForItem(OrderItem item)
				Key值內含於(typed object)時適用.
	public class SimpleOrder : KeyedCollection<int, OrderItem>	// OrderItem為自訂物件
	{
		public SimpleOrder() : base() {}
		protected override int GetKeyForItem(OrderItem item)	//必須覆寫 GetKeyForItem()
		{
			return item.PartNumber;		// Key值內含於(typed object)
		}
	}
        SimpleOrder weekly = new SimpleOrder();
        weekly.Add(new OrderItem(110072674, "Widget", 400, 45.17));	
        Console.WriteLine("\nContains(101030411): {0}", weekly.Contains(101030411));
        Console.WriteLine("\nweekly[101030411].Description: {0}", weekly[101030411].Description);
        weekly.Remove(101030411);
        foreach( OrderItem item in order )
        {
            Console.WriteLine(item);
        }


----------------------- -------	---------------------------------------------------------------------------------
StringCollection	N	List of string
	StringCollection myCol = new StringCollection();
	String[] myArr = new String[] { "RED", "orange", "yellow", "RED", "green", "blue", "RED", "indigo", "violet", "RED" };
	myCol.AddRange( myArr );	// 新增		
	public static void PrintValues1( StringCollection myCol )  {
		foreach ( Object obj in myCol )   // 迴圈建議使用foreach
			Console.WriteLine( "   {0}", obj );
	}

	public static void PrintValues2( StringCollection myCol )  {
		StringEnumerator myEnumerator = myCol.GetEnumerator();	// 迴圈使用enumerator. 
		while ( myEnumerator.MoveNext() )
			Console.WriteLine( "   {0}", myEnumerator.Current );
	}

	public static void PrintValues3( StringCollection myCol )  {
		for ( int i = 0; i < myCol.Count; i++ )		// 迴圈使用Count and Item properties.
			Console.WriteLine( "   {0}", myCol[i] );
	}

----------------------- -------	---------------------------------------------------------------------------------
StringDictionary	N	string keyed list of string.
				不分大小寫.(轉成小寫存放)
	StringDictionary myCol = new StringDictionary();
	myCol.Add(sKey, sValue);		// sKey值重複時, 新增會???
	if ( myCol.ContainsValue(sValue))	// sValue存在否
	if ( myCol.ContainsKey(sKey))		// sKey存在否
	public static void PrintKeysAndValues1( StringDictionary myCol )  {
		foreach ( DictionaryEntry de in myCol )		// 迴圈建議使用foreach
			Console.WriteLine( "   {0,-25} {1}", de.Key, de.Value );
	}

	public static void PrintKeysAndValues2( StringDictionary myCol )  {
		IEnumerator myEnumerator = myCol.GetEnumerator();		// 迴圈使用enumerator. 
		DictionaryEntry de;
		while ( myEnumerator.MoveNext() )  {
			de = (DictionaryEntry) myEnumerator.Current;
			Console.WriteLine( "   {0,-25} {1}", de.Key, de.Value );
		}
	}

	public static void PrintKeysAndValues3( StringDictionary myCol )  {
		String[] myKeys = new String[myCol.Count];
		myCol.Keys.CopyTo( myKeys, 0 );
		for ( int i = 0; i < myCol.Count; i++ )		// 迴圈使用Keys, Values, Count, and Item properties.
			Console.WriteLine( "   {0,-5} {1,-25} {2}", i, myKeys[i], myCol[myKeys[i]] );
	}

	
----------------------- -------	---------------------------------------------------------------------------------
NameValueCollection	N	Keyed list of string.
				同Key時, Value會append.
	NameValueCollection mCol = new NameValueCollection(); 
	mCol.Add(sName, sValue);	// 同Key時, 新增會append 進Value.
	IEnumerator myEnumerator = mCol.GetEnumerator();
	foreach ( String s in mCol.AllKeys )		// 迴圈建議使用foreach
		Console.WriteLine( "   {0,-10} {1}", s, mCol[s] );
	for ( int i = 0; i < mCol.Count; i++ )		// 迴圈使用Count, GetKey(), Get().
		Console.WriteLine( "   [{0}]     {1,-10} {2}", i, mCol.GetKey(i), mCol.Get(i) );


----------------------- -------	---------------------------------------------------------------------------------
○ KeydCollection - Generic
The KeyedCollection class provides both O(1) indexed retrieval and keyed retrieval that approaches O(1). 
It is an abstract type (MustInherit in Visual Basic), or more accurately an infinite set of abstract types, 
because each of its constructed generic types is an abstract base class. 
To use KeyedCollection, derive your collection type from the appropriate constructed type.

The KeyedCollection class is a hybrid between a collection based on the IList generic interface 
and a collection based on the IDictionary generic interface. 
Like collections based on the IList generic interface, KeyedCollection is an indexed list of items. 
Like collections based on the IDictionary generic interface, KeyedCollection has a key associated with each element. 

Unlike dictionaries, an element of KeyedCollection is not a key/value pair; instead, 
the entire element is the value and the key is embedded within the value. 
For example, an element of a collection derived from 
KeyedCollection<String,String> (KeyedCollection(Of String, String) in Visual Basic) 
might be "John Doe Jr." where the value is "John Doe Jr." and the key is "Doe"; 
or a collection of employee records containing integer keys could be derived from KeyedCollection<int,Employee>. 
The abstract (MustOverride in Visual Basic) GetKeyForItem method extracts the key from the element.

By default, the KeyedCollection includes a lookup dictionary. 
When an item is added to the KeyedCollection, the item's key is extracted once and saved in the lookup dictionary for faster searches. 
This behavior is overridden by specifying a dictionary creation threshold when you create the KeyedCollection. 
The lookup dictionary is created the first time the number of elements exceeds that threshold. 
If you specify –1 as the threshold, the lookup dictionary is never created. 

Note:  
When the internal lookup dictionary is used, it contains references to all the items in the collection if TItem is a reference type, 
or copies of all the items in the collection if TItem is a value type. 
Thus, using the lookup dictionary may not be appropriate if TItem is a value type.
 

Every key in a KeyedCollection must be unique. A key cannot be a null reference (Nothing in Visual Basic).

□補充
        // StringDictionary僅支援不分大小寫，需要區分大小寫必須改用hash table
        // Speed up searching-performance via StringDictionary.key. Ignore the StrintDictionary.value
        //StringDictionary mSD = new StringDictionary();


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