1. 鄭士康 國立台灣大學 電機工程學系/電信工程研究所/ 資訊網路與多媒體研究所
集合 (Collection)
鄭士康
國立台灣大學
電機工程學系/電信工程研究所/
資訊網路與多媒體研究所

2. Collection, Enumerator, Enumerable

3. List, ArrayList
動態陣列, 動態加入與刪除, 排序
Enumerator

4. System.Collection IEnumerable IEnumerator ICollection
IDictionaryEnumerator
IList
IDictionary
IComparer
IComparable

5. UsingArrayList.Program (1/9)
using System;
using System.Collections;
namespace UsingArrayList { /*
* 示範ArrayList的使用
* 6/4/2007 */
class Program
static void Main(string[] args)
ArrayList al = new ArrayList();
WriteList(al);

6. UsingArrayList.Program (2/9)
Console.WriteLine(
"加入ID為~14之ObjectElement物件");
for (int i = 0; i < 15; ++i) {
al.Add(new ObjectElement(i)); }
WriteList(al);
"在位置及分別插入ID為及之ObjectElement物件");
al.Insert(8, new ObjectElement(17));
al.Insert(16, new ObjectElement(20));
Console.WriteLine("移走位置,10的物件");
al.Remove(al[2]);
al.RemoveAt(10);

7. UsingArrayList.Program (3/9)
Console.WriteLine("反轉排列順序");
al.Reverse();
WriteList(al);
Console.WriteLine("重新由小而大排序");
al.Sort();
Console.WriteLine("複製ArrayList物件");
ArrayList al2 = (ArrayList)al.Clone();
WriteList(al2);
Console.WriteLine("利用Enumerator取得物件");
IEnumerator enumerator = al.GetEnumerator();
while (enumerator.MoveNext()){
ObjectElement oe = (ObjectElement)
enumerator.Current;
Console.Write(oe.accessID + "\t"); }
Console.WriteLine();

8. UsingArrayList.Program (4/9)
int idx;
ObjectElement oe17 = new ObjectElement(17);
Console.WriteLine("搜尋id為17的物件");
if (al.Contains(oe17)) {
idx = al.BinarySearch(oe17,
new OEComparer());
Console.WriteLine("於位置{0}找到id為17的物件",
idx); }
else
Console.WriteLine("沒有找到id為17的物件");
Console.WriteLine("搜尋id為51的物件");
idx = al.BinarySearch(new ObjectElement(51),

9. UsingArrayList.Program (5/9)
if (idx >= 0) {
Console.WriteLine("於位置{0}找到id為51的物件", idx); }
else
Console.WriteLine("沒有找到id為51的物件");
Console.WriteLine();

10. UsingArrayList.Program (6/9)
static void WriteList(ArrayList al) {
for (int i = 0; i < al.Count; ++i)
ObjectElement oe = (ObjectElement) al[i];
Console.Write(oe.accessID + "\t"); }
Console.WriteLine(
"容量=" + al.Capacity + "; 物件數=" + al.Count);

11. UsingArrayList.Program (7/9)
public class ObjectElement : IComparable {
private int id;
public ObjectElement(int id) {
this.id = id; }
public int accessID {
get { return id; }
public int CompareTo(Object obj) {
ObjectElement oe = (ObjectElement)obj;
return this.id.CompareTo(oe.id);

12. UsingArrayList.Program (8/9)
public override bool Equals(object obj) {
if (obj is ObjectElement)
ObjectElement oe = (ObjectElement)obj;
return this.id == oe.id; }
else
return false;
public override int GetHashCode()
return base.GetHashCode() + id.GetHashCode();

13. UsingArrayList.Program (9/9)
public class OEComparer : IComparer {
public int Compare(Object x, Object y) {
if (x.GetType() == typeof(ObjectElement) &&
y.GetType() == typeof(ObjectElement))
ObjectElement oex = (ObjectElement)x;
ObjectElement oey = (ObjectElement)y;
return oex.CompareTo(oey); }
throw new ArgumentException(
"Use non-ObjectElements for comparison");

14. 練習
撰寫類別Square，模擬邊長為整數a的正方形。注意繼承IComparable介面，定義CompareTo函式，以便比較不同正方形之大小。
撰寫測試程式，建立正方形的ArrayList，嘗試加入或刪除其中元素，反轉排列，重新排序，複製ArrayList、以Enumerator取出所有元素，尋找某一元素。

15. Dictionary, DictionaryEntry, Keys, Values趙大
(02) 錢二
(02) 孫三
(039)333444 李四
(04)666789 周五
(02) 吳六
(02)

16. 介面IDictionary 屬性 函式方法 Object this [ Object key ] { get; set; }
ICollection Keys { get; }
ICollection Values { get; }
函式方法
void Add ( Object key, Object value )
void Clear ()
bool Contains ( Object key )
void Remove ( Object key )
IDictionaryEnumerator GetEnumerator ()

17. 類別DictionaryBase 屬性 函式方法(protected) public int Count
protected IDictionary Dictionary { get; }
函式方法(protected)
virtual void OnInsert ( int index, Object value )
virtual void OnRemove ( int index, Object value )
protected virtual void OnSet ( int index, Object oldValue, Object newValue )
protected virtual void OnValidate ( Object value )

18. UsingDictionaryBase.Program (1/9)
using System;
using System.Collections;
namespace UsingDictionaryBase { /*
* 示範類別DictionaryBase的使用
* ms-help://MS.VSExpressCC.v80/MS.NETFramework.v20.cht/cpref2/html/T_System_Collections_DictionaryBase.htm
* 6/5/2007 */
class Program

19. UsingDictionaryBase.Program (2/9)
static void Main(string[] args) {
// Creates and initializes a new
// DictionaryBase.
ShortStringDictionary mySSC = new
ShortStringDictionary();
// Adds elements to the collection.
mySSC.Add( "One", "a" );
mySSC.Add( "Two", "ab" );
mySSC.Add( "Three", "abc" );
mySSC.Add( "Four", "abcd" );
mySSC.Add( "Five", "abcde" );

20. UsingDictionaryBase.Program (3/9)
// Display the contents of the collection // using foreach. This is the preferred method.
Console.WriteLine(
"Contents of the collection (using foreach):");
PrintKeysAndValues1( mySSC );
// Display the contents of the collection
// using the enumerator.
"Contents of the collection (using enumerator):");
PrintKeysAndValues2( mySSC );
// Display the contents of the collection // using the Keys property and the Item
// property.

21. UsingDictionaryBase.Program (4/9)
Console.WriteLine(
“Contents of the collection (using Keys and Item):");
PrintKeysAndValues3( mySSC );
// Tries to add a value that is too long.
try {
mySSC.Add( "Ten", "abcdefghij" ); }
catch ( ArgumentException e ) {
Console.WriteLine( e.ToString() );

22. UsingDictionaryBase.Program (5/9)
// Tries to add a key that is too long.
try {
mySSC.Add( "Eleven", "ijk" ); }
catch ( ArgumentException e ) {
Console.WriteLine( e.ToString() );
Console.WriteLine();
// Searches the collection with Contains.
Console.WriteLine( "Contains \"Three\": {0}", mySSC.Contains( "Three" ) );
Console.WriteLine( "Contains \"Twelve\": {0}",
mySSC.Contains( "Twelve" ) );

23. UsingDictionaryBase.Program (6/9)
// Removes an element from the collection.
mySSC.Remove( "Two" );
// Displays the contents of the collection.
Console.WriteLine( "After removing \"Two\":" );
PrintKeysAndValues1( mySSC ); }
// Uses the foreach statement which hides the
// complexity of the enumerator.
// NOTE: The foreach statement is the preferred
// way of enumerating the contents of a
// collection.

24. UsingDictionaryBase.Program (7/9)
public static void
PrintKeysAndValues1( ShortStringDictionary myCol ) {
foreach ( DictionaryEntry myDE in myCol )
Console.WriteLine( " {0,-5} : {1}",
myDE.Key, myDE.Value );
Console.WriteLine(); }
// Uses the enumerator.
// NOTE: The foreach statement is the preferred
// way of enumerating the contents of a
// collection.

25. UsingDictionaryBase.Program (8/9)
public static void
PrintKeysAndValues2( ShortStringDictionary myCol ) {
DictionaryEntry myDE;
System.Collections.IEnumerator myEnumerator =
myCol.GetEnumerator();
while ( myEnumerator.MoveNext() )
if ( myEnumerator.Current != null ) {
myDE = (DictionaryEntry)
myEnumerator.Current;
Console.WriteLine( " {0,-5} : {1}",
myDE.Key, myDE.Value ); }
Console.WriteLine();

26. UsingDictionaryBase.Program (9/9)
// Uses the Keys property and the Item property.
public static void
PrintKeysAndValues3( ShortStringDictionary myCol ) {
ICollection myKeys = myCol.Keys;
foreach ( String k in myKeys )
Console.WriteLine( " {0,-5} : {1}", k, myCol[k] );
Console.WriteLine(); }

27. UsingDictionaryBase. ShortStringDictoionary (1/8)
using System;
using System.Collections;
namespace UsingDictionaryBase {
class ShortStringDictionary : DictionaryBase
public String this[String key]
get {
return ((String)Dictionary[key]); }
set {
Dictionary[key] = value;

28. UsingDictionaryBase. ShortStringDictoionary (2/8)
public ICollection Keys {
get {
return (Dictionary.Keys); }
public ICollection Values
return (Dictionary.Values);

29. UsingDictionaryBase. ShortStringDictoionary (3/8)
public void Add(String key, String value) {
Dictionary.Add(key, value); }
public bool Contains(String key)
return (Dictionary.Contains(key));
public void Remove( String key ) {
Dictionary.Remove( key );

30. UsingDictionaryBase. ShortStringDictoionary (4/8)
protected override void OnInsert( Object key,
Object value ) {
CheckKey(key);
CheckValue(value); }
protected override void OnRemove(Object key,
Object value) {
protected override void OnSet(Object key,
Object oldValue, Object newValue)
CheckValue(newValue);

31. UsingDictionaryBase. ShortStringDictoionary (5/8)
protected override void OnValidate(Object key,
Object value) {
CheckKey(key);
CheckValue(value); }
void CheckKey(Object key)
if (key.GetType() != typeof(System.String))
throw new ArgumentException(
"key must be of type String.", "key");
else
String strKey = (String)key;

32. UsingDictionaryBase. ShortStringDictoionary (6/8)
protected override void OnRemove(Object key,
Object value) {
if (key.GetType() != typeof(System.String))
throw new ArgumentException(
"key must be of type String.", "key");
else
String strKey = (String)key;
if (strKey.Length > 5)
"key must be no more than 5 characters in length.",
"key"); }

33. UsingDictionaryBase. ShortStringDictoionary (7/8)
if (strKey.Length > 5)
throw new ArgumentException(
"key must be no more than 5 characters in length.",
"key"); }

34. UsingDictionaryBase. ShortStringDictoionary (8/8)
void CheckValue(Object value) {
if (value.GetType() != typeof(System.String))
throw new ArgumentException(
"value must be of type String.", "value");
else
String strValue = (String)value;
if (strValue.Length > 5)
"value must be no more than 5 characters in length.", "value"); }

35. 練習 繼承DictionaryBase，製作成績表類別GradeTable，以學號為key，0~100之整數為value
寫測試程式加入、刪除、修改成績，並列印結果
加上例外處理