Dictionary<TKey,TValue> 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。
表示索引鍵和值的集合。
generic <typename TKey, typename TValue>
public ref class Dictionary : System::Collections::Generic::ICollection<System::Collections::Generic::KeyValuePair<TKey, TValue>>, System::Collections::Generic::IDictionary<TKey, TValue>, System::Collections::Generic::IEnumerable<System::Collections::Generic::KeyValuePair<TKey, TValue>>, System::Collections::Generic::IReadOnlyCollection<System::Collections::Generic::KeyValuePair<TKey, TValue>>, System::Collections::Generic::IReadOnlyDictionary<TKey, TValue>, System::Collections::IDictionarygeneric <typename TKey, typename TValue>
public ref class Dictionary : System::Collections::Generic::ICollection<System::Collections::Generic::KeyValuePair<TKey, TValue>>, System::Collections::Generic::IDictionary<TKey, TValue>, System::Collections::Generic::IEnumerable<System::Collections::Generic::KeyValuePair<TKey, TValue>>, System::Collections::Generic::IReadOnlyCollection<System::Collections::Generic::KeyValuePair<TKey, TValue>>, System::Collections::Generic::IReadOnlyDictionary<TKey, TValue>, System::Collections::IDictionary, System::Runtime::Serialization::IDeserializationCallback, System::Runtime::Serialization::ISerializablegeneric <typename TKey, typename TValue>
public ref class Dictionary : System::Collections::Generic::ICollection<System::Collections::Generic::KeyValuePair<TKey, TValue>>, System::Collections::Generic::IDictionary<TKey, TValue>, System::Collections::Generic::IEnumerable<System::Collections::Generic::KeyValuePair<TKey, TValue>>, System::Collections::IDictionary, System::Runtime::Serialization::IDeserializationCallback, System::Runtime::Serialization::ISerializablepublic class Dictionary<TKey,TValue> : System.Collections.Generic.ICollection<System.Collections.Generic.KeyValuePair<TKey,TValue>>, System.Collections.Generic.IDictionary<TKey,TValue>, System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey,TValue>>, System.Collections.Generic.IReadOnlyCollection<System.Collections.Generic.KeyValuePair<TKey,TValue>>, System.Collections.Generic.IReadOnlyDictionary<TKey,TValue>, System.Collections.IDictionarypublic class Dictionary<TKey,TValue> : System.Collections.Generic.ICollection<System.Collections.Generic.KeyValuePair<TKey,TValue>>, System.Collections.Generic.IDictionary<TKey,TValue>, System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey,TValue>>, System.Collections.Generic.IReadOnlyCollection<System.Collections.Generic.KeyValuePair<TKey,TValue>>, System.Collections.Generic.IReadOnlyDictionary<TKey,TValue>, System.Collections.IDictionary, System.Runtime.Serialization.IDeserializationCallback, System.Runtime.Serialization.ISerializable[System.Runtime.InteropServices.ComVisible(false)]
[System.Serializable]
public class Dictionary<TKey,TValue> : System.Collections.Generic.ICollection<System.Collections.Generic.KeyValuePair<TKey,TValue>>, System.Collections.Generic.IDictionary<TKey,TValue>, System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey,TValue>>, System.Collections.IDictionary, System.Runtime.Serialization.IDeserializationCallback, System.Runtime.Serialization.ISerializable[System.Runtime.InteropServices.ComVisible(false)]
[System.Serializable]
public class Dictionary<TKey,TValue> : System.Collections.Generic.ICollection<System.Collections.Generic.KeyValuePair<TKey,TValue>>, System.Collections.Generic.IDictionary<TKey,TValue>, System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey,TValue>>, System.Collections.Generic.IReadOnlyCollection<System.Collections.Generic.KeyValuePair<TKey,TValue>>, System.Collections.Generic.IReadOnlyDictionary<TKey,TValue>, System.Collections.IDictionary, System.Runtime.Serialization.IDeserializationCallback, System.Runtime.Serialization.ISerializabletype Dictionary<'Key, 'Value> = class
interface ICollection<KeyValuePair<'Key, 'Value>>
interface seq<KeyValuePair<'Key, 'Value>>
interface IEnumerable
interface IDictionary<'Key, 'Value>
interface IReadOnlyCollection<KeyValuePair<'Key, 'Value>>
interface IReadOnlyDictionary<'Key, 'Value>
interface ICollection
interface IDictionarytype Dictionary<'Key, 'Value> = class
interface ICollection<KeyValuePair<'Key, 'Value>>
interface seq<KeyValuePair<'Key, 'Value>>
interface IEnumerable
interface IDictionary<'Key, 'Value>
interface IReadOnlyCollection<KeyValuePair<'Key, 'Value>>
interface IReadOnlyDictionary<'Key, 'Value>
interface ICollection
interface IDictionary
interface IDeserializationCallback
interface ISerializable[<System.Runtime.InteropServices.ComVisible(false)>]
[<System.Serializable>]
type Dictionary<'Key, 'Value> = class
interface IDictionary<'Key, 'Value>
interface ICollection<KeyValuePair<'Key, 'Value>>
interface seq<KeyValuePair<'Key, 'Value>>
interface IDictionary
interface ICollection
interface IEnumerable
interface ISerializable
interface IDeserializationCallback[<System.Runtime.InteropServices.ComVisible(false)>]
[<System.Serializable>]
type Dictionary<'Key, 'Value> = class
interface IDictionary<'Key, 'Value>
interface ICollection<KeyValuePair<'Key, 'Value>>
interface IDictionary
interface ICollection
interface IReadOnlyDictionary<'Key, 'Value>
interface IReadOnlyCollection<KeyValuePair<'Key, 'Value>>
interface seq<KeyValuePair<'Key, 'Value>>
interface IEnumerable
interface ISerializable
interface IDeserializationCallback[<System.Runtime.InteropServices.ComVisible(false)>]
[<System.Serializable>]
type Dictionary<'Key, 'Value> = class
interface IDictionary<'Key, 'Value>
interface ICollection<KeyValuePair<'Key, 'Value>>
interface seq<KeyValuePair<'Key, 'Value>>
interface IEnumerable
interface IDictionary
interface ICollection
interface IReadOnlyDictionary<'Key, 'Value>
interface IReadOnlyCollection<KeyValuePair<'Key, 'Value>>
interface ISerializable
interface IDeserializationCallbacktype Dictionary<'Key, 'Value> = class
interface IDictionary<'Key, 'Value>
interface ICollection<KeyValuePair<'Key, 'Value>>
interface IReadOnlyDictionary<'Key, 'Value>
interface IReadOnlyCollection<KeyValuePair<'Key, 'Value>>
interface seq<KeyValuePair<'Key, 'Value>>
interface IDictionary
interface ICollection
interface IEnumerable[<System.Runtime.InteropServices.ComVisible(false)>]
[<System.Serializable>]
type Dictionary<'Key, 'Value> = class
interface IDictionary<'Key, 'Value>
interface IDictionary
interface IReadOnlyDictionary<'Key, 'Value>
interface ISerializable
interface IDeserializationCallback
interface ICollection<KeyValuePair<'Key, 'Value>>
interface seq<KeyValuePair<'Key, 'Value>>
interface IEnumerable
interface ICollection
interface IReadOnlyCollection<KeyValuePair<'Key, 'Value>>Public Class Dictionary(Of TKey, TValue)
Implements ICollection(Of KeyValuePair(Of TKey, TValue)), IDictionary, IDictionary(Of TKey, TValue), IEnumerable(Of KeyValuePair(Of TKey, TValue)), IReadOnlyCollection(Of KeyValuePair(Of TKey, TValue)), IReadOnlyDictionary(Of TKey, TValue)Public Class Dictionary(Of TKey, TValue)
Implements ICollection(Of KeyValuePair(Of TKey, TValue)), IDeserializationCallback, IDictionary, IDictionary(Of TKey, TValue), IEnumerable(Of KeyValuePair(Of TKey, TValue)), IReadOnlyCollection(Of KeyValuePair(Of TKey, TValue)), IReadOnlyDictionary(Of TKey, TValue), ISerializablePublic Class Dictionary(Of TKey, TValue)
Implements ICollection(Of KeyValuePair(Of TKey, TValue)), IDeserializationCallback, IDictionary, IDictionary(Of TKey, TValue), IEnumerable(Of KeyValuePair(Of TKey, TValue)), ISerializable類型參數
- TKey
字典中的索引鍵類型。
- TValue
字典中的值類型。
- 繼承
-
Dictionary<TKey,TValue>
- 衍生
- 屬性
- 實作
-
ICollection<KeyValuePair<TKey,TValue>> IDictionary<TKey,TValue> IEnumerable<KeyValuePair<TKey,TValue>> IEnumerable<T> IReadOnlyCollection<KeyValuePair<TKey,TValue>> IReadOnlyDictionary<TKey,TValue> ICollection IDictionary IEnumerable IDeserializationCallback ISerializable
範例
下列程式碼範例會使用字串索引鍵建立空 Dictionary<TKey,TValue> 字串，並使用 Add 方法來加入某些元素。 此範例示範 Add 嘗試加入重複索引鍵時，方法會擲回 ArgumentException 。
此範例使用 Item[] 屬性 (C#) 中的索引子來擷取值，示範 KeyNotFoundException 當要求的索引鍵不存在時擲回 ，並顯示可以取代與索引鍵相關聯的值。
該示例顯示如何使用TryGetValue方法作為更有效的方式來檢索值，如果程序通常必須嘗試不在字典中的鍵值，並且它顯示如何使用ContainsKey方法來測試在調用 Add方法。
此範例示範如何列舉字典中的索引鍵和值，以及如何單獨使用 Keys 屬性和 屬性列舉索引鍵和 Values 值。
最後，此範例會 Remove 示範 方法。
using namespace System;
using namespace System::Collections::Generic;
public ref class Example
{
public:
static void Main()
{
// Create a new dictionary of strings, with string keys.
//
Dictionary<String^, String^>^ openWith =
gcnew Dictionary<String^, String^>();
// Add some elements to the dictionary. There are no
// duplicate keys, but some of the values are duplicates.
openWith->Add("txt", "notepad.exe");
openWith->Add("bmp", "paint.exe");
openWith->Add("dib", "paint.exe");
openWith->Add("rtf", "wordpad.exe");
// The Add method throws an exception if the new key is
// already in the dictionary.
try
{
openWith->Add("txt", "winword.exe");
}
catch (ArgumentException^)
{
Console::WriteLine("An element with Key = \"txt\" already exists.");
}
// The Item property is another name for the indexer, so you
// can omit its name when accessing elements.
Console::WriteLine("For key = \"rtf\", value = {0}.",
openWith["rtf"]);
// The indexer can be used to change the value associated
// with a key.
openWith["rtf"] = "winword.exe";
Console::WriteLine("For key = \"rtf\", value = {0}.",
openWith["rtf"]);
// If a key does not exist, setting the indexer for that key
// adds a new key/value pair.
openWith["doc"] = "winword.exe";
// The indexer throws an exception if the requested key is
// not in the dictionary.
try
{
Console::WriteLine("For key = \"tif\", value = {0}.",
openWith["tif"]);
}
catch (KeyNotFoundException^)
{
Console::WriteLine("Key = \"tif\" is not found.");
}
// When a program often has to try keys that turn out not to
// be in the dictionary, TryGetValue can be a more efficient
// way to retrieve values.
String^ value = "";
if (openWith->TryGetValue("tif", value))
{
Console::WriteLine("For key = \"tif\", value = {0}.", value);
}
else
{
Console::WriteLine("Key = \"tif\" is not found.");
}
// ContainsKey can be used to test keys before inserting
// them.
if (!openWith->ContainsKey("ht"))
{
openWith->Add("ht", "hypertrm.exe");
Console::WriteLine("Value added for key = \"ht\": {0}",
openWith["ht"]);
}
// When you use foreach to enumerate dictionary elements,
// the elements are retrieved as KeyValuePair objects.
Console::WriteLine();
for each( KeyValuePair<String^, String^> kvp in openWith )
{
Console::WriteLine("Key = {0}, Value = {1}",
kvp.Key, kvp.Value);
}
// To get the values alone, use the Values property.
Dictionary<String^, String^>::ValueCollection^ valueColl =
openWith->Values;
// The elements of the ValueCollection are strongly typed
// with the type that was specified for dictionary values.
Console::WriteLine();
for each( String^ s in valueColl )
{
Console::WriteLine("Value = {0}", s);
}
// To get the keys alone, use the Keys property.
Dictionary<String^, String^>::KeyCollection^ keyColl =
openWith->Keys;
// The elements of the KeyCollection are strongly typed
// with the type that was specified for dictionary keys.
Console::WriteLine();
for each( String^ s in keyColl )
{
Console::WriteLine("Key = {0}", s);
}
// Use the Remove method to remove a key/value pair.
Console::WriteLine("\nRemove(\"doc\")");
openWith->Remove("doc");
if (!openWith->ContainsKey("doc"))
{
Console::WriteLine("Key \"doc\" is not found.");
}
}
};
int main()
{
Example::Main();
}
/* This code example produces the following output:
An element with Key = "txt" already exists.
For key = "rtf", value = wordpad.exe.
For key = "rtf", value = winword.exe.
Key = "tif" is not found.
Key = "tif" is not found.
Value added for key = "ht": hypertrm.exe
Key = txt, Value = notepad.exe
Key = bmp, Value = paint.exe
Key = dib, Value = paint.exe
Key = rtf, Value = winword.exe
Key = doc, Value = winword.exe
Key = ht, Value = hypertrm.exe
Value = notepad.exe
Value = paint.exe
Value = paint.exe
Value = winword.exe
Value = winword.exe
Value = hypertrm.exe
Key = txt
Key = bmp
Key = dib
Key = rtf
Key = doc
Key = ht
Remove("doc")
Key "doc" is not found.
*/
// Create a new dictionary of strings, with string keys.
//
Dictionary<string, string> openWith =
new Dictionary<string, string>();
// Add some elements to the dictionary. There are no
// duplicate keys, but some of the values are duplicates.
openWith.Add("txt", "notepad.exe");
openWith.Add("bmp", "paint.exe");
openWith.Add("dib", "paint.exe");
openWith.Add("rtf", "wordpad.exe");
// The Add method throws an exception if the new key is
// already in the dictionary.
try
{
openWith.Add("txt", "winword.exe");
}
catch (ArgumentException)
{
Console.WriteLine("An element with Key = \"txt\" already exists.");
}
// The Item property is another name for the indexer, so you
// can omit its name when accessing elements.
Console.WriteLine("For key = \"rtf\", value = {0}.",
openWith["rtf"]);
// The indexer can be used to change the value associated
// with a key.
openWith["rtf"] = "winword.exe";
Console.WriteLine("For key = \"rtf\", value = {0}.",
openWith["rtf"]);
// If a key does not exist, setting the indexer for that key
// adds a new key/value pair.
openWith["doc"] = "winword.exe";
// The indexer throws an exception if the requested key is
// not in the dictionary.
try
{
Console.WriteLine("For key = \"tif\", value = {0}.",
openWith["tif"]);
}
catch (KeyNotFoundException)
{
Console.WriteLine("Key = \"tif\" is not found.");
}
// When a program often has to try keys that turn out not to
// be in the dictionary, TryGetValue can be a more efficient
// way to retrieve values.
string value = "";
if (openWith.TryGetValue("tif", out value))
{
Console.WriteLine("For key = \"tif\", value = {0}.", value);
}
else
{
Console.WriteLine("Key = \"tif\" is not found.");
}
// ContainsKey can be used to test keys before inserting
// them.
if (!openWith.ContainsKey("ht"))
{
openWith.Add("ht", "hypertrm.exe");
Console.WriteLine("Value added for key = \"ht\": {0}",
openWith["ht"]);
}
// When you use foreach to enumerate dictionary elements,
// the elements are retrieved as KeyValuePair objects.
Console.WriteLine();
foreach( KeyValuePair<string, string> kvp in openWith )
{
Console.WriteLine("Key = {0}, Value = {1}",
kvp.Key, kvp.Value);
}
// To get the values alone, use the Values property.
Dictionary<string, string>.ValueCollection valueColl =
openWith.Values;
// The elements of the ValueCollection are strongly typed
// with the type that was specified for dictionary values.
Console.WriteLine();
foreach( string s in valueColl )
{
Console.WriteLine("Value = {0}", s);
}
// To get the keys alone, use the Keys property.
Dictionary<string, string>.KeyCollection keyColl =
openWith.Keys;
// The elements of the KeyCollection are strongly typed
// with the type that was specified for dictionary keys.
Console.WriteLine();
foreach( string s in keyColl )
{
Console.WriteLine("Key = {0}", s);
}
// Use the Remove method to remove a key/value pair.
Console.WriteLine("\nRemove(\"doc\")");
openWith.Remove("doc");
if (!openWith.ContainsKey("doc"))
{
Console.WriteLine("Key \"doc\" is not found.");
}
/* This code example produces the following output:
An element with Key = "txt" already exists.
For key = "rtf", value = wordpad.exe.
For key = "rtf", value = winword.exe.
Key = "tif" is not found.
Key = "tif" is not found.
Value added for key = "ht": hypertrm.exe
Key = txt, Value = notepad.exe
Key = bmp, Value = paint.exe
Key = dib, Value = paint.exe
Key = rtf, Value = winword.exe
Key = doc, Value = winword.exe
Key = ht, Value = hypertrm.exe
Value = notepad.exe
Value = paint.exe
Value = paint.exe
Value = winword.exe
Value = winword.exe
Value = hypertrm.exe
Key = txt
Key = bmp
Key = dib
Key = rtf
Key = doc
Key = ht
Remove("doc")
Key "doc" is not found.
*/
Imports System.Collections.Generic
Public Class Example
Public Shared Sub Main()
' Create a new dictionary of strings, with string keys.
'
Dim openWith As New Dictionary(Of String, String)
' Add some elements to the dictionary. There are no
' duplicate keys, but some of the values are duplicates.
openWith.Add("txt", "notepad.exe")
openWith.Add("bmp", "paint.exe")
openWith.Add("dib", "paint.exe")
openWith.Add("rtf", "wordpad.exe")
' The Add method throws an exception if the new key is
' already in the dictionary.
Try
openWith.Add("txt", "winword.exe")
Catch
Console.WriteLine("An element with Key = ""txt"" already exists.")
End Try
' The Item property is the default property, so you
' can omit its name when accessing elements.
Console.WriteLine("For key = ""rtf"", value = {0}.", _
openWith("rtf"))
' The default Item property can be used to change the value
' associated with a key.
openWith("rtf") = "winword.exe"
Console.WriteLine("For key = ""rtf"", value = {0}.", _
openWith("rtf"))
' If a key does not exist, setting the default Item property
' for that key adds a new key/value pair.
openWith("doc") = "winword.exe"
' The default Item property throws an exception if the requested
' key is not in the dictionary.
Try
Console.WriteLine("For key = ""tif"", value = {0}.", _
openWith("tif"))
Catch
Console.WriteLine("Key = ""tif"" is not found.")
End Try
' When a program often has to try keys that turn out not to
' be in the dictionary, TryGetValue can be a more efficient
' way to retrieve values.
Dim value As String = ""
If openWith.TryGetValue("tif", value) Then
Console.WriteLine("For key = ""tif"", value = {0}.", value)
Else
Console.WriteLine("Key = ""tif"" is not found.")
End If
' ContainsKey can be used to test keys before inserting
' them.
If Not openWith.ContainsKey("ht") Then
openWith.Add("ht", "hypertrm.exe")
Console.WriteLine("Value added for key = ""ht"": {0}", _
openWith("ht"))
End If
' When you use foreach to enumerate dictionary elements,
' the elements are retrieved as KeyValuePair objects.
Console.WriteLine()
For Each kvp As KeyValuePair(Of String, String) In openWith
Console.WriteLine("Key = {0}, Value = {1}", _
kvp.Key, kvp.Value)
Next kvp
' To get the values alone, use the Values property.
Dim valueColl As _
Dictionary(Of String, String).ValueCollection = _
openWith.Values
' The elements of the ValueCollection are strongly typed
' with the type that was specified for dictionary values.
Console.WriteLine()
For Each s As String In valueColl
Console.WriteLine("Value = {0}", s)
Next s
' To get the keys alone, use the Keys property.
Dim keyColl As _
Dictionary(Of String, String).KeyCollection = _
openWith.Keys
' The elements of the KeyCollection are strongly typed
' with the type that was specified for dictionary keys.
Console.WriteLine()
For Each s As String In keyColl
Console.WriteLine("Key = {0}", s)
Next s
' Use the Remove method to remove a key/value pair.
Console.WriteLine(vbLf + "Remove(""doc"")")
openWith.Remove("doc")
If Not openWith.ContainsKey("doc") Then
Console.WriteLine("Key ""doc"" is not found.")
End If
End Sub
End Class
' This code example produces the following output:
'
'An element with Key = "txt" already exists.
'For key = "rtf", value = wordpad.exe.
'For key = "rtf", value = winword.exe.
'Key = "tif" is not found.
'Key = "tif" is not found.
'Value added for key = "ht": hypertrm.exe
'
'Key = txt, Value = notepad.exe
'Key = bmp, Value = paint.exe
'Key = dib, Value = paint.exe
'Key = rtf, Value = winword.exe
'Key = doc, Value = winword.exe
'Key = ht, Value = hypertrm.exe
'
'Value = notepad.exe
'Value = paint.exe
'Value = paint.exe
'Value = winword.exe
'Value = winword.exe
'Value = hypertrm.exe
'
'Key = txt
'Key = bmp
'Key = dib
'Key = rtf
'Key = doc
'Key = ht
'
'Remove("doc")
'Key "doc" is not found.
'
備註
Dictionary<TKey,TValue>泛型類別提供從一組索引鍵到一組值的對應。 加入字典中的每一個項目都是由值及其關聯索引鍵所組成。 使用索引鍵擷取值非常快速，接近 O (1) ，因為 類別 Dictionary<TKey,TValue> 會實作為雜湊表。
注意
擷取的速度取決於針對 TKey 指定的型別雜湊演算法品質。
只要物件做為 中的 Dictionary<TKey,TValue> 索引鍵使用，它就不得以任何會影響其雜湊值的方式變更。 中的每個 Dictionary<TKey,TValue> 索引鍵都必須根據字典的相等比較子是唯一的。 如果索引鍵的類型是參考型 TValue 別，索引鍵不能是 null ，但值可以是 。
Dictionary<TKey,TValue> 需要相等實作，以判斷索引鍵是否相等。 您可以使用接受 comparer 參數的建構函式來指定泛型介面的 IEqualityComparer<T> 實作;如果您未指定實作，則會使用預設泛型相等比較子 EqualityComparer<T>.Default 。 如果類型 TKey 實作 System.IEquatable<T> 泛型介面，則預設相等比較子會使用該實作。
注意
例如，您可以使用 類別所提供的 StringComparer 不區分大小寫字串比較子來建立不區分大小寫字串索引鍵的字典。
的 Dictionary<TKey,TValue> 容量是 可以保留的專案 Dictionary<TKey,TValue> 數目。 當元素新增至 Dictionary<TKey,TValue> 時，重新配置內部陣列會自動增加容量。
僅限.NET Framework：對於非常大 Dictionary<TKey,TValue> 的物件，您可以在執行時間環境中將組態專案的 true 屬性 <gcAllowVeryLargeObjects> 設定 enabled 為 ，將 64 位系統上的最大容量增加到 20 億個專案。
為了列舉的目的，字典中的每個專案都會被視為 KeyValuePair<TKey,TValue> 表示值及其索引鍵的結構。 傳回專案的順序為未定義。
foreachC++ 中 C# 語言 (for each 的語句， For Each 在 Visual Basic 中) 會傳回集合中專案類型的 物件。 Dictionary<TKey,TValue>因為 是索引鍵和值的集合，所以專案類型不是索引鍵的類型或值的型別。 相反地，元素類型是 KeyValuePair<TKey,TValue> 索引鍵類型和實值型別的 。 例如：
for each(KeyValuePair<String^, String^> kvp in myDictionary)
{
Console::WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value);
}
foreach( KeyValuePair<string, string> kvp in myDictionary )
{
Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value);
}
For Each kvp As KeyValuePair(Of String, String) In myDictionary
Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value)
Next kvp
foreach語句是列舉值周圍的包裝函式，只允許從集合讀取，而不會寫入集合。
注意
因為索引鍵可以繼承並變更其行為，所以使用 方法的比較 Equals 無法保證其絕對唯一性。
建構函式
屬性
| Comparer |
取得 IEqualityComparer<T>，用來判斷字典的索引鍵是否相等。 |
| Count |
取得 Dictionary<TKey,TValue> 中所包含的索引鍵/值組數目。 |
| Item[TKey] |
取得或設定與指定之索引鍵相關聯的值。 |
| Keys |
取得集合，包含 Dictionary<TKey,TValue> 中的索引鍵。 |
| Values |
取得集合，包含 Dictionary<TKey,TValue> 中的值。 |
方法
明確介面實作
擴充方法
適用於
執行緒安全性
Dictionary<TKey,TValue>可以同時支援多個讀取器，只要集合未修改即可。 即使如此，透過集合列舉本質上不是安全線程的程式。 在列舉與寫入存取競爭的罕見情況下，必須在整個列舉期間鎖定集合。 若要讓多重執行緒能夠存取集合以便進行讀取和寫入，您必須實作自己的同步處理。
如需安全線程的替代方案，請參閱 ConcurrentDictionary<TKey,TValue> 類別或 ImmutableDictionary<TKey,TValue> 類別。
Visual Basic 中的公用靜態 (Shared) 此類型的成員是安全線程。
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