Dictionary<TKey,TValue> Dictionary<TKey,TValue> Dictionary<TKey,TValue> Dictionary<TKey,TValue> Constructors

定義

多載

Dictionary<TKey,TValue>() Dictionary<TKey,TValue>() Dictionary<TKey,TValue>()

初始化 Dictionary<TKey,TValue> 類別的新執行個體,這個執行個體是空白的、具有預設的初始容量,並使用索引鍵類型的預設相等比較子。Initializes a new instance of the Dictionary<TKey,TValue> class that is empty, has the default initial capacity, and uses the default equality comparer for the key type.

Dictionary<TKey,TValue>(IDictionary<TKey,TValue>) Dictionary<TKey,TValue>(IDictionary<TKey,TValue>) Dictionary<TKey,TValue>(IDictionary<TKey,TValue>) Dictionary<TKey,TValue>(IDictionary<TKey,TValue>)

初始化 Dictionary<TKey,TValue> 類別的新執行個體,其中包含從指定的 IDictionary<TKey,TValue> 複製的項目,並使用索引鍵類型的預設相等比較子。Initializes a new instance of the Dictionary<TKey,TValue> class that contains elements copied from the specified IDictionary<TKey,TValue> and uses the default equality comparer for the key type.

Dictionary<TKey,TValue>(IEnumerable<KeyValuePair<TKey,TValue>>) Dictionary<TKey,TValue>(IEnumerable<KeyValuePair<TKey,TValue>>) Dictionary<TKey,TValue>(IEnumerable<KeyValuePair<TKey,TValue>>) Dictionary<TKey,TValue>(IEnumerable<KeyValuePair<TKey,TValue>>)
Dictionary<TKey,TValue>(IEqualityComparer<TKey>) Dictionary<TKey,TValue>(IEqualityComparer<TKey>) Dictionary<TKey,TValue>(IEqualityComparer<TKey>) Dictionary<TKey,TValue>(IEqualityComparer<TKey>)

初始化 Dictionary<TKey,TValue> 類別的新執行個體,這個執行個體是空白的、具有預設的初始容量,並使用指定的 IEqualityComparer<T>Initializes a new instance of the Dictionary<TKey,TValue> class that is empty, has the default initial capacity, and uses the specified IEqualityComparer<T>.

Dictionary<TKey,TValue>(Int32) Dictionary<TKey,TValue>(Int32) Dictionary<TKey,TValue>(Int32) Dictionary<TKey,TValue>(Int32)

初始化 Dictionary<TKey,TValue> 類別的新執行個體,這個執行個體是空白的、具有指定的初始容量,並使用索引鍵類型的預設相等比較子。Initializes a new instance of the Dictionary<TKey,TValue> class that is empty, has the specified initial capacity, and uses the default equality comparer for the key type.

Dictionary<TKey,TValue>(IDictionary<TKey,TValue>, IEqualityComparer<TKey>) Dictionary<TKey,TValue>(IDictionary<TKey,TValue>, IEqualityComparer<TKey>) Dictionary<TKey,TValue>(IDictionary<TKey,TValue>, IEqualityComparer<TKey>) Dictionary<TKey,TValue>(IDictionary<TKey,TValue>, IEqualityComparer<TKey>)

初始化 Dictionary<TKey,TValue> 類別的新執行個體,其中包含從指定的 IDictionary<TKey,TValue> 複製的項目,並使用指定的 IEqualityComparer<T>Initializes a new instance of the Dictionary<TKey,TValue> class that contains elements copied from the specified IDictionary<TKey,TValue> and uses the specified IEqualityComparer<T>.

Dictionary<TKey,TValue>(IEnumerable<KeyValuePair<TKey,TValue>>, IEqualityComparer<TKey>) Dictionary<TKey,TValue>(IEnumerable<KeyValuePair<TKey,TValue>>, IEqualityComparer<TKey>) Dictionary<TKey,TValue>(IEnumerable<KeyValuePair<TKey,TValue>>, IEqualityComparer<TKey>) Dictionary<TKey,TValue>(IEnumerable<KeyValuePair<TKey,TValue>>, IEqualityComparer<TKey>)
Dictionary<TKey,TValue>(Int32, IEqualityComparer<TKey>) Dictionary<TKey,TValue>(Int32, IEqualityComparer<TKey>) Dictionary<TKey,TValue>(Int32, IEqualityComparer<TKey>) Dictionary<TKey,TValue>(Int32, IEqualityComparer<TKey>)

初始化 Dictionary<TKey,TValue> 類別的新執行個體,這個執行個體是空白的、具有指定的初始容量,並使用指定的 IEqualityComparer<T>Initializes a new instance of the Dictionary<TKey,TValue> class that is empty, has the specified initial capacity, and uses the specified IEqualityComparer<T>.

Dictionary<TKey,TValue>(SerializationInfo, StreamingContext) Dictionary<TKey,TValue>(SerializationInfo, StreamingContext) Dictionary<TKey,TValue>(SerializationInfo, StreamingContext) Dictionary<TKey,TValue>(SerializationInfo, StreamingContext)

使用序列化資料,初始化 Dictionary<TKey,TValue> 類別的新執行個體。Initializes a new instance of the Dictionary<TKey,TValue> class with serialized data.

Dictionary<TKey,TValue>() Dictionary<TKey,TValue>() Dictionary<TKey,TValue>()

初始化 Dictionary<TKey,TValue> 類別的新執行個體,這個執行個體是空白的、具有預設的初始容量,並使用索引鍵類型的預設相等比較子。Initializes a new instance of the Dictionary<TKey,TValue> class that is empty, has the default initial capacity, and uses the default equality comparer for the key type.

public:
 Dictionary();
public Dictionary ();
Public Sub New ()

範例

下列程式碼範例會建立空Dictionary<TKey,TValue>之字串的字串索引鍵,並使用Add方法來加入一些項目。The following code example creates an empty Dictionary<TKey,TValue> of strings with string keys and uses the Add method to add some elements. 此範例示範Add方法會擲回ArgumentException時嘗試要加入重複的索引鍵。The example demonstrates that the Add method throws an ArgumentException when attempting to add a duplicate key.

此程式碼範例是針對提供之較大範例的一部分Dictionary<TKey,TValue>類別。This code example is part of a larger example provided for the Dictionary<TKey,TValue> class.

// 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.");
}
// 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.");
}
' 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

備註

在每個索引鍵Dictionary<TKey,TValue>必須是唯一根據的預設相等比較子。Every key in a Dictionary<TKey,TValue> must be unique according to the default equality comparer.

Dictionary<TKey,TValue> 需要一個等號比較實作,來判斷索引鍵是否相等。Dictionary<TKey,TValue> requires an equality implementation to determine whether keys are equal. 這個建構函式會使用預設泛型等號比較子, EqualityComparer<T>.DefaultThis constructor uses the default generic equality comparer, EqualityComparer<T>.Default. 如果型別TKey實作System.IEquatable<T>泛型介面的預設相等比較子會使用該實作。If type TKey implements the System.IEquatable<T> generic interface, the default equality comparer uses that implementation. 或者,您可以在其中指定的實作IEqualityComparer<T>泛型介面使用的建構函式可接受comparer參數。Alternatively, you can specify an implementation of the IEqualityComparer<T> generic interface by using a constructor that accepts a comparer parameter.

注意

如果您可以評估集合的大小,使用指定的初始容量建構函式就不需要執行數項調整大小作業新增項目時Dictionary<TKey,TValue>If you can estimate the size of the collection, using a constructor that specifies the initial capacity eliminates the need to perform a number of resizing operations while adding elements to the Dictionary<TKey,TValue>.

這個建構函式是 o (1) 的作業。This constructor is an O(1) operation.

另請參閱

Dictionary<TKey,TValue>(IDictionary<TKey,TValue>) Dictionary<TKey,TValue>(IDictionary<TKey,TValue>) Dictionary<TKey,TValue>(IDictionary<TKey,TValue>) Dictionary<TKey,TValue>(IDictionary<TKey,TValue>)

初始化 Dictionary<TKey,TValue> 類別的新執行個體,其中包含從指定的 IDictionary<TKey,TValue> 複製的項目,並使用索引鍵類型的預設相等比較子。Initializes a new instance of the Dictionary<TKey,TValue> class that contains elements copied from the specified IDictionary<TKey,TValue> and uses the default equality comparer for the key type.

public:
 Dictionary(System::Collections::Generic::IDictionary<TKey, TValue> ^ dictionary);
public Dictionary (System.Collections.Generic.IDictionary<TKey,TValue> dictionary);
new System.Collections.Generic.Dictionary<'Key, 'Value> : System.Collections.Generic.IDictionary<'Key, 'Value> -> System.Collections.Generic.Dictionary<'Key, 'Value>
Public Sub New (dictionary As IDictionary(Of TKey, TValue))

參數

例外狀況

dictionary 包含一或多個重複的索引鍵。dictionary contains one or more duplicate keys.

範例

下列程式碼範例示範如何使用Dictionary<TKey,TValue>(IEqualityComparer<TKey>)建構函式來初始化Dictionary<TKey,TValue>與排序從另一個字典的內容。The following code example shows how to use the Dictionary<TKey,TValue>(IEqualityComparer<TKey>) constructor to initialize a Dictionary<TKey,TValue> with sorted content from another dictionary. 此程式碼範例會建立SortedDictionary<TKey,TValue>並填入資料,以隨機順序,然後傳遞SortedDictionary<TKey,TValue>Dictionary<TKey,TValue>(IEqualityComparer<TKey>)建構函式,建立Dictionary<TKey,TValue>的排序。The code example creates a SortedDictionary<TKey,TValue> and populates it with data in random order, then passes the SortedDictionary<TKey,TValue> to the Dictionary<TKey,TValue>(IEqualityComparer<TKey>) constructor, creating a Dictionary<TKey,TValue> that is sorted. 如果您要建置的已排序的字典,在某個時間點變成靜態的這非常有用複製的資料SortedDictionary<TKey,TValue>Dictionary<TKey,TValue>改善擷取的速度。This is useful if you need to build a sorted dictionary that at some point becomes static; copying the data from a SortedDictionary<TKey,TValue> to a Dictionary<TKey,TValue> improves retrieval speed.

using System;
using System.Collections.Generic;

public class Example
{
    public static void Main()
    {
        // Create a new sorted dictionary of strings, with string 
        // keys.
        SortedDictionary<string, string> openWith = 
            new SortedDictionary<string, string>();
        
        // Add some elements to the dictionary. 
        openWith.Add("txt", "notepad.exe");
        openWith.Add("bmp", "paint.exe");
        openWith.Add("dib", "paint.exe");
        openWith.Add("rtf", "wordpad.exe");
        
        // Create a Dictionary of strings with string keys, and 
        // initialize it with the contents of the sorted dictionary.
        Dictionary<string, string> copy = 
            new Dictionary<string, string>(openWith);

        // List the contents of the copy.
        Console.WriteLine();
        foreach( KeyValuePair<string, string> kvp in copy )
        {
            Console.WriteLine("Key = {0}, Value = {1}", 
               kvp.Key, kvp.Value);
        }
    }
}

/* This code example produces the following output:

Key = bmp, Value = paint.exe
Key = dib, Value = paint.exe
Key = rtf, Value = wordpad.exe
Key = txt, Value = notepad.exe
 */
Imports System
Imports System.Collections.Generic

Public Class Example
    
    Public Shared Sub Main() 

        ' Create a new sorted dictionary of strings, with string 
        ' keys.
        Dim openWith As New SortedDictionary(Of String, String)
        
        ' Add some elements to the sorted dictionary. 
        openWith.Add("txt", "notepad.exe")
        openWith.Add("bmp", "paint.exe")
        openWith.Add("dib", "paint.exe")
        openWith.Add("rtf", "wordpad.exe")
        
        ' Create a Dictionary of strings with string keys, and 
        ' initialize it with the contents of the sorted dictionary.
        Dim copy As New Dictionary(Of String, String)(openWith)

        ' List the contents of the copy.
        Console.WriteLine()
        For Each kvp As KeyValuePair(Of String, String) In copy
            Console.WriteLine("Key = {0}, Value = {1}", _
                kvp.Key, kvp.Value)
        Next kvp

    End Sub

End Class

' This code example produces the following output:
'
'Key = bmp, Value = paint.exe
'Key = dib, Value = paint.exe
'Key = rtf, Value = wordpad.exe
'Key = txt, Value = notepad.exe

備註

在每個索引鍵Dictionary<TKey,TValue>必須是唯一,根據預設值的相等比較子,同樣地,在來源中的每個金鑰dictionary也必須是唯一根據的預設相等比較子。Every key in a Dictionary<TKey,TValue> must be unique according to the default equality comparer; likewise, every key in the source dictionary must also be unique according to the default equality comparer.

新的初始容量Dictionary<TKey,TValue>夠大,足以包含所有項目dictionaryThe initial capacity of the new Dictionary<TKey,TValue> is large enough to contain all the elements in dictionary.

Dictionary<TKey,TValue> 需要一個等號比較實作,來判斷索引鍵是否相等。Dictionary<TKey,TValue> requires an equality implementation to determine whether keys are equal. 這個建構函式會使用預設泛型等號比較子, EqualityComparer<T>.DefaultThis constructor uses the default generic equality comparer, EqualityComparer<T>.Default. 如果型別TKey實作System.IEquatable<T>泛型介面的預設相等比較子會使用該實作。If type TKey implements the System.IEquatable<T> generic interface, the default equality comparer uses that implementation. 或者,您可以在其中指定的實作IEqualityComparer<T>泛型介面使用的建構函式可接受comparer參數。Alternatively, you can specify an implementation of the IEqualityComparer<T> generic interface by using a constructor that accepts a comparer parameter.

這個建構函式是 o (n) 運算,其中 n 是中的項目數dictionaryThis constructor is an O(n) operation, where n is the number of elements in dictionary.

另請參閱

Dictionary<TKey,TValue>(IEnumerable<KeyValuePair<TKey,TValue>>) Dictionary<TKey,TValue>(IEnumerable<KeyValuePair<TKey,TValue>>) Dictionary<TKey,TValue>(IEnumerable<KeyValuePair<TKey,TValue>>) Dictionary<TKey,TValue>(IEnumerable<KeyValuePair<TKey,TValue>>)

public:
 Dictionary(System::Collections::Generic::IEnumerable<System::Collections::Generic::KeyValuePair<TKey, TValue>> ^ collection);
public Dictionary (System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey,TValue>> collection);
new System.Collections.Generic.Dictionary<'Key, 'Value> : seq<System.Collections.Generic.KeyValuePair<'Key, 'Value>> -> System.Collections.Generic.Dictionary<'Key, 'Value>
Public Sub New (collection As IEnumerable(Of KeyValuePair(Of TKey, TValue)))

參數

collection
IEnumerable<KeyValuePair<TKey,TValue>>

Dictionary<TKey,TValue>(IEqualityComparer<TKey>) Dictionary<TKey,TValue>(IEqualityComparer<TKey>) Dictionary<TKey,TValue>(IEqualityComparer<TKey>) Dictionary<TKey,TValue>(IEqualityComparer<TKey>)

初始化 Dictionary<TKey,TValue> 類別的新執行個體,這個執行個體是空白的、具有預設的初始容量,並使用指定的 IEqualityComparer<T>Initializes a new instance of the Dictionary<TKey,TValue> class that is empty, has the default initial capacity, and uses the specified IEqualityComparer<T>.

public:
 Dictionary(System::Collections::Generic::IEqualityComparer<TKey> ^ comparer);
public Dictionary (System.Collections.Generic.IEqualityComparer<TKey> comparer);
new System.Collections.Generic.Dictionary<'Key, 'Value> : System.Collections.Generic.IEqualityComparer<'Key> -> System.Collections.Generic.Dictionary<'Key, 'Value>
Public Sub New (comparer As IEqualityComparer(Of TKey))

參數

comparer
IEqualityComparer<TKey>

比較索引鍵時所要使用的 IEqualityComparer<T> 實作,或是 null,表示要為索引鍵的類型使用預設 EqualityComparer<T>The IEqualityComparer<T> implementation to use when comparing keys, or null to use the default EqualityComparer<T> for the type of the key.

範例

下列程式碼範例會建立Dictionary<TKey,TValue>與目前的文化特性的不區分大小寫的等號比較子。The following code example creates a Dictionary<TKey,TValue> with a case-insensitive equality comparer for the current culture. 範例會將四個項目、 一些具有小寫的索引鍵和一些具有大寫索引鍵。The example adds four elements, some with lower-case keys and some with upper-case keys. 然後此範例會嘗試從現有的索引鍵只有大小寫不同,索引鍵中加入項目攔截到產生的例外狀況,並顯示錯誤訊息。The example then attempts to add an element with a key that differs from an existing key only by case, catches the resulting exception, and displays an error message. 最後,此範例會顯示在字典中的項目。Finally, the example displays the elements in the dictionary.

using System;
using System.Collections.Generic;

public class Example
{
    public static void Main()
    {
        // Create a new Dictionary of strings, with string keys 
        // and a case-insensitive comparer for the current culture.
        Dictionary<string, string> openWith = 
                      new Dictionary<string, string>( 
                          StringComparer.CurrentCultureIgnoreCase);
        
        // Add some elements to the dictionary.
        openWith.Add("txt", "notepad.exe");
        openWith.Add("bmp", "paint.exe");
        openWith.Add("DIB", "paint.exe");
        openWith.Add("rtf", "wordpad.exe");

        // Try to add a fifth element with a key that is the same 
        // except for case; this would be allowed with the default
        // comparer.
        try
        {
            openWith.Add("BMP", "paint.exe");
        }
        catch (ArgumentException)
        {
            Console.WriteLine("\nBMP is already in the dictionary.");
        }
        
        // List the contents of the sorted dictionary.
        Console.WriteLine();
        foreach( KeyValuePair<string, string> kvp in openWith )
        {
            Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, 
                kvp.Value);
        }
    }
}

/* This code example produces the following output:

BMP is already in the dictionary.

Key = txt, Value = notepad.exe
Key = bmp, Value = paint.exe
Key = DIB, Value = paint.exe
Key = rtf, Value = wordpad.exe
 */
Imports System
Imports System.Collections.Generic

Public Class Example
    
    Public Shared Sub Main() 

        ' Create a new Dictionary of strings, with string keys 
        ' and a case-insensitive comparer for the current culture.
        Dim openWith As New Dictionary(Of String, String)( _
            StringComparer.CurrentCultureIgnoreCase)
        
        ' Add some elements to the dictionary. 
        openWith.Add("txt", "notepad.exe")
        openWith.Add("bmp", "paint.exe")
        openWith.Add("DIB", "paint.exe")
        openWith.Add("rtf", "wordpad.exe")

        ' Try to add a fifth element with a key that is the same 
        ' except for case; this would be allowed with the default
        ' comparer.
        Try
            openWith.Add("BMP", "paint.exe")
        Catch ex As ArgumentException
            Console.WriteLine(vbLf & "BMP is already in the dictionary.")
        End Try
        
        ' List the contents of the dictionary.
        Console.WriteLine()
        For Each kvp As KeyValuePair(Of String, String) In openWith
            Console.WriteLine("Key = {0}, Value = {1}", _
                kvp.Key, kvp.Value)
        Next kvp

    End Sub

End Class

' This code example produces the following output:
'
'BMP is already in the dictionary.
'
'Key = txt, Value = notepad.exe
'Key = bmp, Value = paint.exe
'Key = DIB, Value = paint.exe
'Key = rtf, Value = wordpad.exe

備註

這個建構函式使用所提供的不區分大小寫的字串比較子StringComparer類別來建立具有不區分大小寫的字串索引鍵的字典。Use this constructor with the case-insensitive string comparers provided by the StringComparer class to create dictionaries with case-insensitive string keys.

在每個索引鍵Dictionary<TKey,TValue>必須是唯一根據指定的比較子。Every key in a Dictionary<TKey,TValue> must be unique according to the specified comparer.

Dictionary<TKey,TValue> 需要一個等號比較實作,來判斷索引鍵是否相等。Dictionary<TKey,TValue> requires an equality implementation to determine whether keys are equal. 如果comparernull,這個建構函式會使用預設泛型等號比較子, EqualityComparer<T>.DefaultIf comparer is null, this constructor uses the default generic equality comparer, EqualityComparer<T>.Default. 如果型別TKey實作System.IEquatable<T>泛型介面的預設相等比較子會使用該實作。If type TKey implements the System.IEquatable<T> generic interface, the default equality comparer uses that implementation.

注意

如果您可以評估集合的大小,使用指定的初始容量建構函式就不需要執行數項調整大小作業新增項目時Dictionary<TKey,TValue>If you can estimate the size of the collection, using a constructor that specifies the initial capacity eliminates the need to perform a number of resizing operations while adding elements to the Dictionary<TKey,TValue>.

這個建構函式是 o (1) 的作業。This constructor is an O(1) operation.

另請參閱

Dictionary<TKey,TValue>(Int32) Dictionary<TKey,TValue>(Int32) Dictionary<TKey,TValue>(Int32) Dictionary<TKey,TValue>(Int32)

初始化 Dictionary<TKey,TValue> 類別的新執行個體,這個執行個體是空白的、具有指定的初始容量,並使用索引鍵類型的預設相等比較子。Initializes a new instance of the Dictionary<TKey,TValue> class that is empty, has the specified initial capacity, and uses the default equality comparer for the key type.

public:
 Dictionary(int capacity);
public Dictionary (int capacity);
new System.Collections.Generic.Dictionary<'Key, 'Value> : int -> System.Collections.Generic.Dictionary<'Key, 'Value>
Public Sub New (capacity As Integer)

參數

capacity
Int32 Int32 Int32 Int32

Dictionary<TKey,TValue> 可包含的初始項目數。The initial number of elements that the Dictionary<TKey,TValue> can contain.

例外狀況

範例

下列程式碼範例會建立字典的初始容量,共 4,並填入 4 個項目。The following code example creates a dictionary with an initial capacity of 4 and populates it with 4 entries.

using System;
using System.Collections.Generic;

public class Example
{
    public static void Main()
    {
        // Create a new dictionary of strings, with string keys and
        // an initial capacity of 4.
        Dictionary<string, string> openWith = 
                               new Dictionary<string, string>(4);
        
        // Add 4 elements to the dictionary. 
        openWith.Add("txt", "notepad.exe");
        openWith.Add("bmp", "paint.exe");
        openWith.Add("dib", "paint.exe");
        openWith.Add("rtf", "wordpad.exe");
        
        // List the contents of the dictionary.
        Console.WriteLine();
        foreach( KeyValuePair<string, string> kvp in openWith )
        {
            Console.WriteLine("Key = {0}, Value = {1}", 
               kvp.Key, kvp.Value);
        }
    }
}

/* This code example produces the following output:

Key = txt, Value = notepad.exe
Key = bmp, Value = paint.exe
Key = dib, Value = paint.exe
Key = rtf, Value = wordpad.exe
 */
Imports System
Imports System.Collections.Generic

Public Class Example
    
    Public Shared Sub Main() 

        ' Create a new dictionary of strings, with string keys and
        ' an initial capacity of 4.
        Dim openWith As New Dictionary(Of String, String)(4)
        
        ' Add 4 elements to the dictionary. 
        openWith.Add("txt", "notepad.exe")
        openWith.Add("bmp", "paint.exe")
        openWith.Add("dib", "paint.exe")
        openWith.Add("rtf", "wordpad.exe")
        
        ' List the contents of the dictionary.
        Console.WriteLine()
        For Each kvp As KeyValuePair(Of String, String) In openWith
            Console.WriteLine("Key = {0}, Value = {1}", _
                kvp.Key, kvp.Value)
        Next kvp

    End Sub

End Class

' This code example produces the following output:
'
'Key = txt, Value = notepad.exe
'Key = bmp, Value = paint.exe
'Key = dib, Value = paint.exe
'Key = rtf, Value = wordpad.exe

備註

在每個索引鍵Dictionary<TKey,TValue>必須是唯一根據的預設相等比較子。Every key in a Dictionary<TKey,TValue> must be unique according to the default equality comparer.

營運Dictionary<TKey,TValue>是可加入的項目數Dictionary<TKey,TValue>之前調整大小是必要的。The capacity of a Dictionary<TKey,TValue> is the number of elements that can be added to the Dictionary<TKey,TValue> before resizing is necessary. 當項目新增至Dictionary<TKey,TValue>,自動增加容量的要求以重新配置內部陣列。As elements are added to a Dictionary<TKey,TValue>, the capacity is automatically increased as required by reallocating the internal array.

如果可以估計集合的大小,指定初始容量,就不需要執行數項調整大小作業新增項目時Dictionary<TKey,TValue>If the size of the collection can be estimated, specifying the initial capacity eliminates the need to perform a number of resizing operations while adding elements to the Dictionary<TKey,TValue>.

Dictionary<TKey,TValue> 需要一個等號比較實作,來判斷索引鍵是否相等。Dictionary<TKey,TValue> requires an equality implementation to determine whether keys are equal. 這個建構函式會使用預設泛型等號比較子, EqualityComparer<T>.DefaultThis constructor uses the default generic equality comparer, EqualityComparer<T>.Default. 如果型別TKey實作System.IEquatable<T>泛型介面的預設相等比較子會使用該實作。If type TKey implements the System.IEquatable<T> generic interface, the default equality comparer uses that implementation. 或者,您可以在其中指定的實作IEqualityComparer<T>泛型介面使用的建構函式可接受comparer參數。Alternatively, you can specify an implementation of the IEqualityComparer<T> generic interface by using a constructor that accepts a comparer parameter.

這個建構函式是 o (1) 的作業。This constructor is an O(1) operation.

另請參閱

Dictionary<TKey,TValue>(IDictionary<TKey,TValue>, IEqualityComparer<TKey>) Dictionary<TKey,TValue>(IDictionary<TKey,TValue>, IEqualityComparer<TKey>) Dictionary<TKey,TValue>(IDictionary<TKey,TValue>, IEqualityComparer<TKey>) Dictionary<TKey,TValue>(IDictionary<TKey,TValue>, IEqualityComparer<TKey>)

初始化 Dictionary<TKey,TValue> 類別的新執行個體,其中包含從指定的 IDictionary<TKey,TValue> 複製的項目,並使用指定的 IEqualityComparer<T>Initializes a new instance of the Dictionary<TKey,TValue> class that contains elements copied from the specified IDictionary<TKey,TValue> and uses the specified IEqualityComparer<T>.

public:
 Dictionary(System::Collections::Generic::IDictionary<TKey, TValue> ^ dictionary, System::Collections::Generic::IEqualityComparer<TKey> ^ comparer);
public Dictionary (System.Collections.Generic.IDictionary<TKey,TValue> dictionary, System.Collections.Generic.IEqualityComparer<TKey> comparer);
new System.Collections.Generic.Dictionary<'Key, 'Value> : System.Collections.Generic.IDictionary<'Key, 'Value> * System.Collections.Generic.IEqualityComparer<'Key> -> System.Collections.Generic.Dictionary<'Key, 'Value>
Public Sub New (dictionary As IDictionary(Of TKey, TValue), comparer As IEqualityComparer(Of TKey))

參數

comparer
IEqualityComparer<TKey>

比較索引鍵時所要使用的 IEqualityComparer<T> 實作,或是 null,表示要為索引鍵的類型使用預設 EqualityComparer<T>The IEqualityComparer<T> implementation to use when comparing keys, or null to use the default EqualityComparer<T> for the type of the key.

例外狀況

dictionary 包含一或多個重複的索引鍵。dictionary contains one or more duplicate keys.

範例

下列程式碼範例示範如何使用Dictionary<TKey,TValue>(IDictionary<TKey,TValue>, IEqualityComparer<TKey>)建構函式來初始化Dictionary<TKey,TValue>使用不區分大小寫排序的內容,從另一個字典。The following code example shows how to use the Dictionary<TKey,TValue>(IDictionary<TKey,TValue>, IEqualityComparer<TKey>) constructor to initialize a Dictionary<TKey,TValue> with case-insensitive sorted content from another dictionary. 此程式碼範例會建立SortedDictionary<TKey,TValue>不區分大小寫的比較子並填入資料,以隨機順序,然後傳遞SortedDictionary<TKey,TValue>Dictionary<TKey,TValue>(IDictionary<TKey,TValue>, IEqualityComparer<TKey>)建構函式、 不區分大小寫的等號比較子,建立以及Dictionary<TKey,TValue>會排序。The code example creates a SortedDictionary<TKey,TValue> with a case-insensitive comparer and populates it with data in random order, then passes the SortedDictionary<TKey,TValue> to the Dictionary<TKey,TValue>(IDictionary<TKey,TValue>, IEqualityComparer<TKey>) constructor, along with a case-insensitive equality comparer, creating a Dictionary<TKey,TValue> that is sorted. 如果您要建置的已排序的字典,在某個時間點變成靜態的這非常有用複製的資料SortedDictionary<TKey,TValue>Dictionary<TKey,TValue>改善擷取的速度。This is useful if you need to build a sorted dictionary that at some point becomes static; copying the data from a SortedDictionary<TKey,TValue> to a Dictionary<TKey,TValue> improves retrieval speed.

注意

當您使用不區分大小寫的比較子建立新的字典,並填入項目字典中,使用區分大小寫的比較子,如同此範例中,如果輸入的字典有只有大小寫不同的索引鍵,也會發生例外狀況。When you create a new dictionary with a case-insensitive comparer and populate it with entries from a dictionary that uses a case-sensitive comparer, as in this example, an exception occurs if the input dictionary has keys that differ only by case.

using System;
using System.Collections.Generic;

public class Example
{
    public static void Main()
    {
        // Create a new sorted dictionary of strings, with string 
        // keys and a case-insensitive comparer.
        SortedDictionary<string, string> openWith = 
                new SortedDictionary<string, string>(
                    StringComparer.CurrentCultureIgnoreCase);
        
        // Add some elements to the dictionary. 
        openWith.Add("txt", "notepad.exe");
        openWith.Add("Bmp", "paint.exe");
        openWith.Add("DIB", "paint.exe");
        openWith.Add("rtf", "wordpad.exe");
        
        // Create a Dictionary of strings with string keys and a
        // case-insensitive equality comparer, and initialize it
        // with the contents of the sorted dictionary.
        Dictionary<string, string> copy = 
                new Dictionary<string, string>(openWith, 
                    StringComparer.CurrentCultureIgnoreCase);

        // List the contents of the copy.
        Console.WriteLine();
        foreach( KeyValuePair<string, string> kvp in copy )
        {
            Console.WriteLine("Key = {0}, Value = {1}", 
               kvp.Key, kvp.Value);
        }
    }
}

/* This code example produces the following output:

Key = Bmp, Value = paint.exe
Key = DIB, Value = paint.exe
Key = rtf, Value = wordpad.exe
Key = txt, Value = notepad.exe
 */
Imports System
Imports System.Collections.Generic

Public Class Example
    
    Public Shared Sub Main() 

        ' Create a new sorted dictionary of strings, with string 
        ' keys and a case-insensitive comparer.
        Dim openWith As New SortedDictionary(Of String, String)( _
            StringComparer.CurrentCultureIgnoreCase)
        
        ' Add some elements to the sorted dictionary. 
        openWith.Add("txt", "notepad.exe")
        openWith.Add("Bmp", "paint.exe")
        openWith.Add("DIB", "paint.exe")
        openWith.Add("rtf", "wordpad.exe")
        
        ' Create a Dictionary of strings with string keys and a 
        ' case-insensitive equality comparer, and initialize it
        ' with the contents of the sorted dictionary.
        Dim copy As New Dictionary(Of String, String)(openWith, _
            StringComparer.CurrentCultureIgnoreCase)

        ' List the contents of the copy.
        Console.WriteLine()
        For Each kvp As KeyValuePair(Of String, String) In copy
            Console.WriteLine("Key = {0}, Value = {1}", _
                kvp.Key, kvp.Value)
        Next kvp

    End Sub

End Class

' This code example produces the following output:
'
'Key = Bmp, Value = paint.exe
'Key = DIB, Value = paint.exe
'Key = rtf, Value = wordpad.exe
'Key = txt, Value = notepad.exe

備註

這個建構函式使用所提供的不區分大小寫的字串比較子StringComparer類別來建立具有不區分大小寫的字串索引鍵的字典。Use this constructor with the case-insensitive string comparers provided by the StringComparer class to create dictionaries with case-insensitive string keys.

在每個索引鍵Dictionary<TKey,TValue>必須是唯一根據指定的比較子,同樣地,在來源中的每個金鑰dictionary也必須是唯一根據指定的比較子。Every key in a Dictionary<TKey,TValue> must be unique according to the specified comparer; likewise, every key in the source dictionary must also be unique according to the specified comparer.

注意

例如,如果可能會發生重複的索引鍵comparer是所提供的不區分大小寫的字串比較子的其中一個StringComparer類別和dictionary不會使用不區分大小寫的比較子機碼。For example, duplicate keys can occur if comparer is one of the case-insensitive string comparers provided by the StringComparer class and dictionary does not use a case-insensitive comparer key.

新的初始容量Dictionary<TKey,TValue>夠大,足以包含所有項目dictionaryThe initial capacity of the new Dictionary<TKey,TValue> is large enough to contain all the elements in dictionary.

Dictionary<TKey,TValue> 需要一個等號比較實作,來判斷索引鍵是否相等。Dictionary<TKey,TValue> requires an equality implementation to determine whether keys are equal. 如果comparernull,這個建構函式會使用預設泛型等號比較子, EqualityComparer<T>.DefaultIf comparer is null, this constructor uses the default generic equality comparer, EqualityComparer<T>.Default. 如果型別TKey實作System.IEquatable<T>泛型介面的預設相等比較子會使用該實作。If type TKey implements the System.IEquatable<T> generic interface, the default equality comparer uses that implementation.

這個建構函式是 O (n) 運算,其中n是中的項目數dictionaryThis constructor is an O(n) operation, where n is the number of elements in dictionary.

另請參閱

Dictionary<TKey,TValue>(IEnumerable<KeyValuePair<TKey,TValue>>, IEqualityComparer<TKey>) Dictionary<TKey,TValue>(IEnumerable<KeyValuePair<TKey,TValue>>, IEqualityComparer<TKey>) Dictionary<TKey,TValue>(IEnumerable<KeyValuePair<TKey,TValue>>, IEqualityComparer<TKey>) Dictionary<TKey,TValue>(IEnumerable<KeyValuePair<TKey,TValue>>, IEqualityComparer<TKey>)

public:
 Dictionary(System::Collections::Generic::IEnumerable<System::Collections::Generic::KeyValuePair<TKey, TValue>> ^ collection, System::Collections::Generic::IEqualityComparer<TKey> ^ comparer);
public Dictionary (System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey,TValue>> collection, System.Collections.Generic.IEqualityComparer<TKey> comparer);
new System.Collections.Generic.Dictionary<'Key, 'Value> : seq<System.Collections.Generic.KeyValuePair<'Key, 'Value>> * System.Collections.Generic.IEqualityComparer<'Key> -> System.Collections.Generic.Dictionary<'Key, 'Value>
Public Sub New (collection As IEnumerable(Of KeyValuePair(Of TKey, TValue)), comparer As IEqualityComparer(Of TKey))

參數

collection
IEnumerable<KeyValuePair<TKey,TValue>>
comparer
IEqualityComparer<TKey>

Dictionary<TKey,TValue>(Int32, IEqualityComparer<TKey>) Dictionary<TKey,TValue>(Int32, IEqualityComparer<TKey>) Dictionary<TKey,TValue>(Int32, IEqualityComparer<TKey>) Dictionary<TKey,TValue>(Int32, IEqualityComparer<TKey>)

初始化 Dictionary<TKey,TValue> 類別的新執行個體,這個執行個體是空白的、具有指定的初始容量,並使用指定的 IEqualityComparer<T>Initializes a new instance of the Dictionary<TKey,TValue> class that is empty, has the specified initial capacity, and uses the specified IEqualityComparer<T>.

public:
 Dictionary(int capacity, System::Collections::Generic::IEqualityComparer<TKey> ^ comparer);
public Dictionary (int capacity, System.Collections.Generic.IEqualityComparer<TKey> comparer);
new System.Collections.Generic.Dictionary<'Key, 'Value> : int * System.Collections.Generic.IEqualityComparer<'Key> -> System.Collections.Generic.Dictionary<'Key, 'Value>
Public Sub New (capacity As Integer, comparer As IEqualityComparer(Of TKey))

參數

capacity
Int32 Int32 Int32 Int32

Dictionary<TKey,TValue> 可包含的初始項目數。The initial number of elements that the Dictionary<TKey,TValue> can contain.

comparer
IEqualityComparer<TKey>

比較索引鍵時所要使用的 IEqualityComparer<T> 實作,或是 null,表示要為索引鍵的類型使用預設 EqualityComparer<T>The IEqualityComparer<T> implementation to use when comparing keys, or null to use the default EqualityComparer<T> for the type of the key.

例外狀況

範例

下列程式碼範例會建立Dictionary<TKey,TValue>5 和不區分大小寫的等號比較子的目前文化特性的初始容量。The following code example creates a Dictionary<TKey,TValue> with an initial capacity of 5 and a case-insensitive equality comparer for the current culture. 範例會將四個項目、 一些具有小寫的索引鍵和一些具有大寫索引鍵。The example adds four elements, some with lower-case keys and some with upper-case keys. 然後此範例會嘗試從現有的索引鍵只有大小寫不同,索引鍵中加入項目攔截到產生的例外狀況,並顯示錯誤訊息。The example then attempts to add an element with a key that differs from an existing key only by case, catches the resulting exception, and displays an error message. 最後,此範例會顯示在字典中的項目。Finally, the example displays the elements in the dictionary.

using System;
using System.Collections.Generic;

public class Example
{
    public static void Main()
    {
        // Create a new dictionary of strings, with string keys, an
        // initial capacity of 5, and a case-insensitive equality 
        // comparer.
        Dictionary<string, string> openWith = 
                      new Dictionary<string, string>(5, 
                          StringComparer.CurrentCultureIgnoreCase);
        
        // Add 4 elements to the dictionary. 
        openWith.Add("txt", "notepad.exe");
        openWith.Add("bmp", "paint.exe");
        openWith.Add("DIB", "paint.exe");
        openWith.Add("rtf", "wordpad.exe");

        // Try to add a fifth element with a key that is the same 
        // except for case; this would be allowed with the default
        // comparer.
        try
        {
            openWith.Add("BMP", "paint.exe");
        }
        catch (ArgumentException)
        {
            Console.WriteLine("\nBMP is already in the dictionary.");
        }
        
        // List the contents of the dictionary.
        Console.WriteLine();
        foreach( KeyValuePair<string, string> kvp in openWith )
        {
            Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, 
                kvp.Value);
        }
    }
}

/* This code example produces the following output:

BMP is already in the dictionary.

Key = txt, Value = notepad.exe
Key = bmp, Value = paint.exe
Key = DIB, Value = paint.exe
Key = rtf, Value = wordpad.exe
 */
Imports System
Imports System.Collections.Generic

Public Class Example
    
    Public Shared Sub Main() 

        ' Create a new Dictionary of strings, with string keys, an
        ' initial capacity of 5, and a case-insensitive equality
        ' comparer.
        Dim openWith As New Dictionary(Of String, String)(5, _
            StringComparer.CurrentCultureIgnoreCase)
        
        ' Add 4 elements to the dictionary. 
        openWith.Add("txt", "notepad.exe")
        openWith.Add("bmp", "paint.exe")
        openWith.Add("DIB", "paint.exe")
        openWith.Add("rtf", "wordpad.exe")

        ' Try to add a fifth element with a key that is the same 
        ' except for case; this would be allowed with the default
        ' comparer.
        Try
            openWith.Add("BMP", "paint.exe")
        Catch ex As ArgumentException
            Console.WriteLine(vbLf & "BMP is already in the dictionary.")
        End Try
        
        ' List the contents of the dictionary.
        Console.WriteLine()
        For Each kvp As KeyValuePair(Of String, String) In openWith
            Console.WriteLine("Key = {0}, Value = {1}", _
                kvp.Key, kvp.Value)
        Next kvp

    End Sub

End Class

' This code example produces the following output:
'
'BMP is already in the dictionary.
'
'Key = txt, Value = notepad.exe
'Key = bmp, Value = paint.exe
'Key = DIB, Value = paint.exe
'Key = rtf, Value = wordpad.exe

備註

這個建構函式使用所提供的不區分大小寫的字串比較子StringComparer類別來建立具有不區分大小寫的字串索引鍵的字典。Use this constructor with the case-insensitive string comparers provided by the StringComparer class to create dictionaries with case-insensitive string keys.

在每個索引鍵Dictionary<TKey,TValue>必須是唯一根據指定的比較子。Every key in a Dictionary<TKey,TValue> must be unique according to the specified comparer.

營運Dictionary<TKey,TValue>是可加入的項目數Dictionary<TKey,TValue>之前調整大小是必要的。The capacity of a Dictionary<TKey,TValue> is the number of elements that can be added to the Dictionary<TKey,TValue> before resizing is necessary. 當項目新增至Dictionary<TKey,TValue>,自動增加容量的要求以重新配置內部陣列。As elements are added to a Dictionary<TKey,TValue>, the capacity is automatically increased as required by reallocating the internal array.

如果可以估計集合的大小,指定初始容量,就不需要執行數項調整大小作業新增項目時Dictionary<TKey,TValue>If the size of the collection can be estimated, specifying the initial capacity eliminates the need to perform a number of resizing operations while adding elements to the Dictionary<TKey,TValue>.

Dictionary<TKey,TValue> 需要一個等號比較實作,來判斷索引鍵是否相等。Dictionary<TKey,TValue> requires an equality implementation to determine whether keys are equal. 如果comparernull,這個建構函式會使用預設泛型等號比較子, EqualityComparer<T>.DefaultIf comparer is null, this constructor uses the default generic equality comparer, EqualityComparer<T>.Default. 如果型別TKey實作System.IEquatable<T>泛型介面的預設相等比較子會使用該實作。If type TKey implements the System.IEquatable<T> generic interface, the default equality comparer uses that implementation.

這個建構函式是 o (1) 的作業。This constructor is an O(1) operation.

另請參閱

Dictionary<TKey,TValue>(SerializationInfo, StreamingContext) Dictionary<TKey,TValue>(SerializationInfo, StreamingContext) Dictionary<TKey,TValue>(SerializationInfo, StreamingContext) Dictionary<TKey,TValue>(SerializationInfo, StreamingContext)

使用序列化資料,初始化 Dictionary<TKey,TValue> 類別的新執行個體。Initializes a new instance of the Dictionary<TKey,TValue> class with serialized data.

protected:
 Dictionary(System::Runtime::Serialization::SerializationInfo ^ info, System::Runtime::Serialization::StreamingContext context);
protected Dictionary (System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context);
new System.Collections.Generic.Dictionary<'Key, 'Value> : System.Runtime.Serialization.SerializationInfo * System.Runtime.Serialization.StreamingContext -> System.Collections.Generic.Dictionary<'Key, 'Value>
Protected Sub New (info As SerializationInfo, context As StreamingContext)

參數

info
SerializationInfo SerializationInfo SerializationInfo SerializationInfo

SerializationInfo 物件,包含序列化 Dictionary<TKey,TValue> 所需的資訊。A SerializationInfo object containing the information required to serialize the Dictionary<TKey,TValue>.

context
StreamingContext StreamingContext StreamingContext StreamingContext

StreamingContext 結構,包含與 Dictionary<TKey,TValue> 相關聯之已序列化資料流的來源和目的地。A StreamingContext structure containing the source and destination of the serialized stream associated with the Dictionary<TKey,TValue>.

備註

以重新構成經由資料流傳送的物件還原序列化期間,會呼叫這個建構函式。This constructor is called during deserialization to reconstitute an object transmitted over a stream. 如需詳細資訊,請參閱 < XML 和 SOAP 序列化For more information, see XML and SOAP Serialization.

另請參閱

適用於