Collection<T> 類別
定義
重要
部分資訊涉及發行前產品,在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊,不做任何明確或隱含的瑕疵擔保。
提供泛型集合的基類。
generic <typename T>
public ref class Collection : System::Collections::Generic::ICollection<T>, System::Collections::Generic::IEnumerable<T>, System::Collections::Generic::IList<T>, System::Collections::Generic::IReadOnlyCollection<T>, System::Collections::Generic::IReadOnlyList<T>, System::Collections::IList
generic <typename T>
public ref class Collection : System::Collections::Generic::ICollection<T>, System::Collections::Generic::IEnumerable<T>, System::Collections::Generic::IList<T>, System::Collections::IList
public class Collection<T> : System.Collections.Generic.ICollection<T>, System.Collections.Generic.IEnumerable<T>, System.Collections.Generic.IList<T>, System.Collections.Generic.IReadOnlyCollection<T>, System.Collections.Generic.IReadOnlyList<T>, System.Collections.IList
[System.Runtime.InteropServices.ComVisible(false)]
[System.Serializable]
public class Collection<T> : System.Collections.Generic.ICollection<T>, System.Collections.Generic.IEnumerable<T>, System.Collections.Generic.IList<T>, System.Collections.IList
[System.Runtime.InteropServices.ComVisible(false)]
[System.Serializable]
public class Collection<T> : System.Collections.Generic.ICollection<T>, System.Collections.Generic.IEnumerable<T>, System.Collections.Generic.IList<T>, System.Collections.Generic.IReadOnlyCollection<T>, System.Collections.Generic.IReadOnlyList<T>, System.Collections.IList
type Collection<'T> = class
interface ICollection<'T>
interface seq<'T>
interface IEnumerable
interface IList<'T>
interface IReadOnlyCollection<'T>
interface IReadOnlyList<'T>
interface ICollection
interface IList
[<System.Runtime.InteropServices.ComVisible(false)>]
[<System.Serializable>]
type Collection<'T> = class
interface IList<'T>
interface ICollection<'T>
interface seq<'T>
interface IList
interface ICollection
interface IEnumerable
[<System.Runtime.InteropServices.ComVisible(false)>]
[<System.Serializable>]
type Collection<'T> = class
interface IList<'T>
interface ICollection<'T>
interface IList
interface ICollection
interface IReadOnlyList<'T>
interface IReadOnlyCollection<'T>
interface seq<'T>
interface IEnumerable
[<System.Runtime.InteropServices.ComVisible(false)>]
[<System.Serializable>]
type Collection<'T> = class
interface IList<'T>
interface ICollection<'T>
interface seq<'T>
interface IEnumerable
interface IList
interface ICollection
interface IReadOnlyList<'T>
interface IReadOnlyCollection<'T>
type Collection<'T> = class
interface IList<'T>
interface ICollection<'T>
interface IReadOnlyList<'T>
interface IReadOnlyCollection<'T>
interface seq<'T>
interface IList
interface ICollection
interface IEnumerable
Public Class Collection(Of T)
Implements ICollection(Of T), IEnumerable(Of T), IList, IList(Of T), IReadOnlyCollection(Of T), IReadOnlyList(Of T)
Public Class Collection(Of T)
Implements ICollection(Of T), IEnumerable(Of T), IList, IList(Of T)
類型參數
- T
集合中的項目類型。
- 繼承
-
Collection<T>
- 衍生
- 屬性
- 實作
範例
本節包含兩個程式代碼範例。 第一個範例展示了該 Collection<T> 類別的多項性質與方法。 第二個範例展示了如何從構造型態 Collection<T>的 衍生出集合類別,以及如何覆寫 的 Collection<T> 受保護方法以提供自訂行為。
範例 1
以下程式碼範例展示了 的 Collection<T>許多性質與方法 。 程式碼範例建立一組字串,使用 Add 該方法加入多個字串,顯示 Count,並列出字串。 範例中使用了 IndexOf 尋找字串索引的方法,以及 Contains 判斷字串是否屬於集合的方法。 範例中會用該 Insert 方法插入字串,並利用預設 Item[] 屬性(C# 中的索引器)檢索與設定字串。 範例中用字 Remove 串單位元移除字串,並用該 RemoveAt 方法移除索引。 最後, Clear 該方法會被用來清除集合中的所有字串。
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
public class Demo
{
public static void Main()
{
Collection<string> dinosaurs = new Collection<string>();
dinosaurs.Add("Psitticosaurus");
dinosaurs.Add("Caudipteryx");
dinosaurs.Add("Compsognathus");
dinosaurs.Add("Muttaburrasaurus");
Console.WriteLine("{0} dinosaurs:", dinosaurs.Count);
Display(dinosaurs);
Console.WriteLine("\nIndexOf(\"Muttaburrasaurus\"): {0}",
dinosaurs.IndexOf("Muttaburrasaurus"));
Console.WriteLine("\nContains(\"Caudipteryx\"): {0}",
dinosaurs.Contains("Caudipteryx"));
Console.WriteLine("\nInsert(2, \"Nanotyrannus\")");
dinosaurs.Insert(2, "Nanotyrannus");
Display(dinosaurs);
Console.WriteLine("\ndinosaurs[2]: {0}", dinosaurs[2]);
Console.WriteLine("\ndinosaurs[2] = \"Microraptor\"");
dinosaurs[2] = "Microraptor";
Display(dinosaurs);
Console.WriteLine("\nRemove(\"Microraptor\")");
dinosaurs.Remove("Microraptor");
Display(dinosaurs);
Console.WriteLine("\nRemoveAt(0)");
dinosaurs.RemoveAt(0);
Display(dinosaurs);
Console.WriteLine("\ndinosaurs.Clear()");
dinosaurs.Clear();
Console.WriteLine("Count: {0}", dinosaurs.Count);
}
private static void Display(Collection<string> cs)
{
Console.WriteLine();
foreach( string item in cs )
{
Console.WriteLine(item);
}
}
}
/* This code example produces the following output:
4 dinosaurs:
Psitticosaurus
Caudipteryx
Compsognathus
Muttaburrasaurus
IndexOf("Muttaburrasaurus"): 3
Contains("Caudipteryx"): True
Insert(2, "Nanotyrannus")
Psitticosaurus
Caudipteryx
Nanotyrannus
Compsognathus
Muttaburrasaurus
dinosaurs[2]: Nanotyrannus
dinosaurs[2] = "Microraptor"
Psitticosaurus
Caudipteryx
Microraptor
Compsognathus
Muttaburrasaurus
Remove("Microraptor")
Psitticosaurus
Caudipteryx
Compsognathus
Muttaburrasaurus
RemoveAt(0)
Caudipteryx
Compsognathus
Muttaburrasaurus
dinosaurs.Clear()
Count: 0
*/
Imports System.Collections.Generic
Imports System.Collections.ObjectModel
Public Class Demo
Public Shared Sub Main()
Dim dinosaurs As New Collection(Of String)
dinosaurs.Add("Psitticosaurus")
dinosaurs.Add("Caudipteryx")
dinosaurs.Add("Compsognathus")
dinosaurs.Add("Muttaburrasaurus")
Console.WriteLine("{0} dinosaurs:", dinosaurs.Count)
Display(dinosaurs)
Console.WriteLine(vbLf & "IndexOf(""Muttaburrasaurus""): {0}", _
dinosaurs.IndexOf("Muttaburrasaurus"))
Console.WriteLine(vbLf & "Contains(""Caudipteryx""): {0}", _
dinosaurs.Contains("Caudipteryx"))
Console.WriteLine(vbLf & "Insert(2, ""Nanotyrannus"")")
dinosaurs.Insert(2, "Nanotyrannus")
Display(dinosaurs)
Console.WriteLine(vbLf & "dinosaurs(2): {0}", dinosaurs(2))
Console.WriteLine(vbLf & "dinosaurs(2) = ""Microraptor""")
dinosaurs(2) = "Microraptor"
Display(dinosaurs)
Console.WriteLine(vbLf & "Remove(""Microraptor"")")
dinosaurs.Remove("Microraptor")
Display(dinosaurs)
Console.WriteLine(vbLf & "RemoveAt(0)")
dinosaurs.RemoveAt(0)
Display(dinosaurs)
Console.WriteLine(vbLf & "dinosaurs.Clear()")
dinosaurs.Clear()
Console.WriteLine("Count: {0}", dinosaurs.Count)
End Sub
Private Shared Sub Display(ByVal cs As Collection(Of String))
Console.WriteLine()
For Each item As String In cs
Console.WriteLine(item)
Next item
End Sub
End Class
' This code example produces the following output:
'
'4 dinosaurs:
'
'Psitticosaurus
'Caudipteryx
'Compsognathus
'Muttaburrasaurus
'
'IndexOf("Muttaburrasaurus"): 3
'
'Contains("Caudipteryx"): True
'
'Insert(2, "Nanotyrannus")
'
'Psitticosaurus
'Caudipteryx
'Nanotyrannus
'Compsognathus
'Muttaburrasaurus
'
'dinosaurs(2): Nanotyrannus
'
'dinosaurs(2) = "Microraptor"
'
'Psitticosaurus
'Caudipteryx
'Microraptor
'Compsognathus
'Muttaburrasaurus
'
'Remove("Microraptor")
'
'Psitticosaurus
'Caudipteryx
'Compsognathus
'Muttaburrasaurus
'
'RemoveAt(0)
'
'Caudipteryx
'Compsognathus
'Muttaburrasaurus
'
'dinosaurs.Clear()
'Count: 0
範例 2
以下程式碼範例說明如何從建構型Collection<T>態衍生出集合類別,以及如何覆寫受保護InsertItem的 、 RemoveItem、 ClearItems和 SetItem 方法,以提供自訂行為,適用於 Add、 Insert、 RemoveClear 和 方法,以及設定屬性Item[]。
此範例提供的自訂行為是在 Changed 每個受保護方法結束時觸發的通知事件。
Dinosaurs 類別繼承了 Collection<string>(Visual Basic 中為 Collection(Of String)),並定義了 Changed 事件,該事件使用 DinosaursChangedEventArgs 類別作為事件資訊,並以列舉方式識別變化類型。
程式碼範例呼叫了 Collection<T> 多個屬性與方法來展示自訂事件。
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
public class Dinosaurs : Collection<string>
{
public event EventHandler<DinosaursChangedEventArgs> Changed;
protected override void InsertItem(int index, string newItem)
{
base.InsertItem(index, newItem);
EventHandler<DinosaursChangedEventArgs> temp = Changed;
if (temp != null)
{
temp(this, new DinosaursChangedEventArgs(
ChangeType.Added, newItem, null));
}
}
protected override void SetItem(int index, string newItem)
{
string replaced = Items[index];
base.SetItem(index, newItem);
EventHandler<DinosaursChangedEventArgs> temp = Changed;
if (temp != null)
{
temp(this, new DinosaursChangedEventArgs(
ChangeType.Replaced, replaced, newItem));
}
}
protected override void RemoveItem(int index)
{
string removedItem = Items[index];
base.RemoveItem(index);
EventHandler<DinosaursChangedEventArgs> temp = Changed;
if (temp != null)
{
temp(this, new DinosaursChangedEventArgs(
ChangeType.Removed, removedItem, null));
}
}
protected override void ClearItems()
{
base.ClearItems();
EventHandler<DinosaursChangedEventArgs> temp = Changed;
if (temp != null)
{
temp(this, new DinosaursChangedEventArgs(
ChangeType.Cleared, null, null));
}
}
}
// Event argument for the Changed event.
//
public class DinosaursChangedEventArgs : EventArgs
{
public readonly string ChangedItem;
public readonly ChangeType ChangeType;
public readonly string ReplacedWith;
public DinosaursChangedEventArgs(ChangeType change, string item,
string replacement)
{
ChangeType = change;
ChangedItem = item;
ReplacedWith = replacement;
}
}
public enum ChangeType
{
Added,
Removed,
Replaced,
Cleared
};
public class Demo
{
public static void Main()
{
Dinosaurs dinosaurs = new Dinosaurs();
dinosaurs.Changed += ChangedHandler;
dinosaurs.Add("Psitticosaurus");
dinosaurs.Add("Caudipteryx");
dinosaurs.Add("Compsognathus");
dinosaurs.Add("Muttaburrasaurus");
Display(dinosaurs);
Console.WriteLine("\nIndexOf(\"Muttaburrasaurus\"): {0}",
dinosaurs.IndexOf("Muttaburrasaurus"));
Console.WriteLine("\nContains(\"Caudipteryx\"): {0}",
dinosaurs.Contains("Caudipteryx"));
Console.WriteLine("\nInsert(2, \"Nanotyrannus\")");
dinosaurs.Insert(2, "Nanotyrannus");
Console.WriteLine("\ndinosaurs[2]: {0}", dinosaurs[2]);
Console.WriteLine("\ndinosaurs[2] = \"Microraptor\"");
dinosaurs[2] = "Microraptor";
Console.WriteLine("\nRemove(\"Microraptor\")");
dinosaurs.Remove("Microraptor");
Console.WriteLine("\nRemoveAt(0)");
dinosaurs.RemoveAt(0);
Display(dinosaurs);
}
private static void Display(Collection<string> cs)
{
Console.WriteLine();
foreach( string item in cs )
{
Console.WriteLine(item);
}
}
private static void ChangedHandler(object source,
DinosaursChangedEventArgs e)
{
if (e.ChangeType==ChangeType.Replaced)
{
Console.WriteLine("{0} was replaced with {1}", e.ChangedItem,
e.ReplacedWith);
}
else if(e.ChangeType==ChangeType.Cleared)
{
Console.WriteLine("The dinosaur list was cleared.");
}
else
{
Console.WriteLine("{0} was {1}.", e.ChangedItem, e.ChangeType);
}
}
}
/* This code example produces the following output:
Psitticosaurus was Added.
Caudipteryx was Added.
Compsognathus was Added.
Muttaburrasaurus was Added.
Psitticosaurus
Caudipteryx
Compsognathus
Muttaburrasaurus
IndexOf("Muttaburrasaurus"): 3
Contains("Caudipteryx"): True
Insert(2, "Nanotyrannus")
Nanotyrannus was Added.
dinosaurs[2]: Nanotyrannus
dinosaurs[2] = "Microraptor"
Nanotyrannus was replaced with Microraptor
Remove("Microraptor")
Microraptor was Removed.
RemoveAt(0)
Psitticosaurus was Removed.
Caudipteryx
Compsognathus
Muttaburrasaurus
*/
Imports System.Collections.Generic
Imports System.Collections.ObjectModel
Public Class Dinosaurs
Inherits Collection(Of String)
Public Event Changed As EventHandler(Of DinosaursChangedEventArgs)
Protected Overrides Sub InsertItem( _
ByVal index As Integer, ByVal newItem As String)
MyBase.InsertItem(index, newItem)
RaiseEvent Changed(Me, New DinosaursChangedEventArgs( _
ChangeType.Added, newItem, Nothing))
End Sub
Protected Overrides Sub SetItem(ByVal index As Integer, _
ByVal newItem As String)
Dim replaced As String = Items(index)
MyBase.SetItem(index, newItem)
RaiseEvent Changed(Me, New DinosaursChangedEventArgs( _
ChangeType.Replaced, replaced, newItem))
End Sub
Protected Overrides Sub RemoveItem(ByVal index As Integer)
Dim removedItem As String = Items(index)
MyBase.RemoveItem(index)
RaiseEvent Changed(Me, New DinosaursChangedEventArgs( _
ChangeType.Removed, removedItem, Nothing))
End Sub
Protected Overrides Sub ClearItems()
MyBase.ClearItems()
RaiseEvent Changed(Me, New DinosaursChangedEventArgs( _
ChangeType.Cleared, Nothing, Nothing))
End Sub
End Class
' Event argument for the Changed event.
'
Public Class DinosaursChangedEventArgs
Inherits EventArgs
Public ReadOnly ChangedItem As String
Public ReadOnly ChangeType As ChangeType
Public ReadOnly ReplacedWith As String
Public Sub New(ByVal change As ChangeType, ByVal item As String, _
ByVal replacement As String)
ChangeType = change
ChangedItem = item
ReplacedWith = replacement
End Sub
End Class
Public Enum ChangeType
Added
Removed
Replaced
Cleared
End Enum
Public Class Demo
Public Shared Sub Main()
Dim dinosaurs As New Dinosaurs
AddHandler dinosaurs.Changed, AddressOf ChangedHandler
dinosaurs.Add("Psitticosaurus")
dinosaurs.Add("Caudipteryx")
dinosaurs.Add("Compsognathus")
dinosaurs.Add("Muttaburrasaurus")
Display(dinosaurs)
Console.WriteLine(vbLf & "IndexOf(""Muttaburrasaurus""): {0}", _
dinosaurs.IndexOf("Muttaburrasaurus"))
Console.WriteLine(vbLf & "Contains(""Caudipteryx""): {0}", _
dinosaurs.Contains("Caudipteryx"))
Console.WriteLine(vbLf & "Insert(2, ""Nanotyrannus"")")
dinosaurs.Insert(2, "Nanotyrannus")
Console.WriteLine(vbLf & "dinosaurs(2): {0}", dinosaurs(2))
Console.WriteLine(vbLf & "dinosaurs(2) = ""Microraptor""")
dinosaurs(2) = "Microraptor"
Console.WriteLine(vbLf & "Remove(""Microraptor"")")
dinosaurs.Remove("Microraptor")
Console.WriteLine(vbLf & "RemoveAt(0)")
dinosaurs.RemoveAt(0)
Display(dinosaurs)
End Sub
Private Shared Sub Display(ByVal cs As Collection(Of String))
Console.WriteLine()
For Each item As String In cs
Console.WriteLine(item)
Next item
End Sub
Private Shared Sub ChangedHandler(ByVal source As Object, _
ByVal e As DinosaursChangedEventArgs)
If e.ChangeType = ChangeType.Replaced Then
Console.WriteLine("{0} was replaced with {1}", _
e.ChangedItem, e.ReplacedWith)
ElseIf e.ChangeType = ChangeType.Cleared Then
Console.WriteLine("The dinosaur list was cleared.")
Else
Console.WriteLine("{0} was {1}.", _
e.ChangedItem, e.ChangeType)
End If
End Sub
End Class
' This code example produces the following output:
'
'Psitticosaurus was Added.
'Caudipteryx was Added.
'Compsognathus was Added.
'Muttaburrasaurus was Added.
'
'Psitticosaurus
'Caudipteryx
'Compsognathus
'Muttaburrasaurus
'
'IndexOf("Muttaburrasaurus"): 3
'
'Contains("Caudipteryx"): True
'
'Insert(2, "Nanotyrannus")
'Nanotyrannus was Added.
'
'dinosaurs(2): Nanotyrannus
'
'dinosaurs(2) = "Microraptor"
'Nanotyrannus was replaced with Microraptor
'
'Remove("Microraptor")
'Microraptor was Removed.
'
'RemoveAt(0)
'Psitticosaurus was Removed.
'
'Caudipteryx
'Compsognathus
'Muttaburrasaurus
備註
Collection<T>這個類別可以透過建立其構造型別的實例立即使用;你只需要指定要包含在集合中的物件類型即可。 此外,你也可以從任何建構型態推導出自己的集合型別,或從 Collection<T> 類別本身推導出通用型態集合型別。
該 Collection<T> 類別提供受保護的方法,可用於自訂其在新增與移除項目、清除集合或設定現有項目值時的行為。
大多數 Collection<T> 物件都可以被修改。 然而,以唯讀Collection<T>物件初始化的物件則IList<T>無法被修改。 請參閱 ReadOnlyCollection<T> 此類別的唯讀版本。
這個集合中的元素可以使用整數索引來存取。 此集合中的索引是以零起始。
Collection<T> 接受 null 作為參考類型的有效值,並允許重複元素。
給繼承者的注意事項
此基底類別的提供目的是讓實作者更容易建立自訂集合。 實作者被鼓勵擴充此基底類別,而非自行創建。
建構函式
| 名稱 | Description |
|---|---|
| Collection<T>() |
初始化一個空的類別新實例 Collection<T> 。 |
| Collection<T>(IList<T>) |
初始化該類別的新實例 Collection<T> ,作為指定清單的包裝器。 |
屬性
| 名稱 | Description |
|---|---|
| Count |
取得實際包含在 Collection<T>中的項目數目。 |
| Item[Int32] |
取得或設定位於指定索引處的專案。 |
| Items |
會被 IList<T> 包裹在 Collection<T>. |
方法
| 名稱 | Description |
|---|---|
| Add(T) |
將物件加入至 Collection<T>的結尾。 |
| Clear() |
從 Collection<T>移除所有專案。 |
| ClearItems() |
從 Collection<T>移除所有專案。 |
| Contains(T) |
判斷專案是否在 Collection<T>中。 |
| CopyTo(T[], Int32) |
從目標陣列的指定索引開始,將整個 Collection<T> 複製到相容的一維 Array。 |
| Equals(Object) |
判斷指定的物件是否等於目前的物件。 (繼承來源 Object) |
| GetEnumerator() |
回傳一個遍歷 的 Collection<T>枚舉子。 |
| GetHashCode() |
做為預設哈希函式。 (繼承來源 Object) |
| GetType() |
取得目前實例的 Type。 (繼承來源 Object) |
| IndexOf(T) |
搜尋指定物件,並回傳整個 Collection<T>中首次出現的零基索引。 |
| Insert(Int32, T) |
將專案插入指定索引處的 Collection<T>。 |
| InsertItem(Int32, T) |
將專案插入指定索引處的 Collection<T>。 |
| MemberwiseClone() |
建立目前 Object的淺層複本。 (繼承來源 Object) |
| Remove(T) |
從 Collection<T>移除第一個出現的特定物件。 |
| RemoveAt(Int32) |
拿掉位於 Collection<T>之指定索引處的專案。 |
| RemoveItem(Int32) |
拿掉位於 Collection<T>之指定索引處的專案。 |
| SetItem(Int32, T) |
取代位於指定索引處的專案。 |
| ToString() |
傳回表示目前 物件的字串。 (繼承來源 Object) |
明確介面實作
| 名稱 | Description |
|---|---|
| ICollection.CopyTo(Array, Int32) |
從特定ICollection索引開始,將 的Array元素複製到 Array。 |
| ICollection.IsSynchronized |
取得值,指出是否同步存取 ICollection (線程安全)。 |
| ICollection.SyncRoot |
取得一個物件,可用來同步存取 ICollection。 |
| ICollection<T>.IsReadOnly |
取得值,指出 ICollection<T> 是否為唯讀。 |
| IEnumerable.GetEnumerator() |
傳回逐一查看集合的列舉值。 |
| IList.Add(Object) |
將一個項目加入 IList。 |
| IList.Contains(Object) |
判斷是否 IList 包含特定值。 |
| IList.IndexOf(Object) |
決定特定項目的 IList索引。 |
| IList.Insert(Int32, Object) |
在指定的索引處插入一個項目 IList 。 |
| IList.IsFixedSize |
取得值,指出 IList 是否有固定大小。 |
| IList.IsReadOnly |
取得值,指出 IList 是否為唯讀。 |
| IList.Item[Int32] |
取得或設定位於指定索引處的專案。 |
| IList.Remove(Object) |
從 IList移除第一個出現的特定物件。 |
擴充方法
適用於
執行緒安全性
此類型的公用靜態 (Shared) 成員是安全線程。 任何實例成員都不保證具有執行緒安全性。
Collection<T> A 可以同時支援多個讀取器,只要集合不被修改。 即便如此,透過集合列舉本質上不是安全線程的程式。 若要保證列舉期間的線程安全性,您可以在整個列舉期間鎖定集合。 若要允許多個線程存取集合以進行讀取和寫入,您必須實作自己的同步處理。