IDictionary<TKey,TValue> 接口

定义

表示键/值对的泛型集合。Represents a generic collection of key/value pairs.

generic <typename TKey, typename TValue>
public interface class IDictionary : System::Collections::Generic::ICollection<System::Collections::Generic::KeyValuePair<TKey, TValue>>, System::Collections::Generic::IEnumerable<System::Collections::Generic::KeyValuePair<TKey, TValue>>
public interface IDictionary<TKey,TValue> : System.Collections.Generic.ICollection<System.Collections.Generic.KeyValuePair<TKey,TValue>>, System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey,TValue>>
type IDictionary<'Key, 'Value> = interface
    interface ICollection<KeyValuePair<'Key, 'Value>>
    interface seq<KeyValuePair<'Key, 'Value>>
    interface IEnumerable
Public Interface IDictionary(Of TKey, TValue)
Implements ICollection(Of KeyValuePair(Of TKey, TValue)), IEnumerable(Of KeyValuePair(Of TKey, TValue))

类型参数

TKey

字典中的键的类型。The type of keys in the dictionary.

TValue

字典中值的类型。The type of values in the dictionary.

派生
实现

示例

下面的代码示例 Dictionary<TKey,TValue> 使用字符串键创建一个空的字符串,并通过接口进行访问 IDictionary<TKey,TValue>The following code example creates an empty Dictionary<TKey,TValue> of strings, with string keys, and accesses it through the IDictionary<TKey,TValue> interface.

此代码示例使用 Add 方法添加一些元素。The code example uses the Add method to add some elements. 该示例演示了在 Add ArgumentException 尝试添加重复键时该方法将引发。The example demonstrates that the Add method throws ArgumentException when attempting to add a duplicate key.

该示例使用 Item[] 属性 (c # 中的索引器 ) 来检索值,演示在 KeyNotFoundException 请求的键不存在时引发的,并显示与键关联的值可以替换。The example uses the Item[] property (the indexer in C#) to retrieve values, demonstrating that a KeyNotFoundException is thrown when a requested key is not present, and showing that the value associated with a key can be replaced.

该示例演示了如何使用 TryGetValue 方法来检索值(如果程序经常必须尝试字典中不存在的键值),以及如何使用 ContainsKey 方法测试在调用方法之前是否存在某个键 AddThe example shows how to use the TryGetValue method as a more efficient way to retrieve values if a program often must try key values that are not in the dictionary, and how to use the ContainsKey method to test whether a key exists prior to calling the Add method.

最后,该示例演示如何枚举字典中的键和值,以及如何使用属性单独枚举值 ValuesFinally, the example shows how to enumerate the keys and values in the dictionary, and how to enumerate the values alone using the Values property.

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,
        // and access it through the IDictionary generic interface.
        IDictionary<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.
        ICollection<String^>^ icoll = 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 icoll )
        {
            Console::WriteLine("Value = {0}", s);
        }

        // To get the keys alone, use the Keys property.
        icoll = openWith->Keys;

        // The elements of the ValueCollection are strongly typed
        // with the type that was specified for dictionary values.
        Console::WriteLine();
        for each( String^ s in icoll )
        {
            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.
 */
using System;
using System.Collections.Generic;

public class Example
{
    public static void Main()
    {
        // Create a new dictionary of strings, with string keys,
        // and access it through the IDictionary generic interface.
        IDictionary<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.
        ICollection<string> icoll = 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 icoll )
        {
            Console.WriteLine("Value = {0}", s);
        }

        // To get the keys alone, use the Keys property.
        icoll = openWith.Keys;

        // The elements of the ValueCollection are strongly typed
        // with the type that was specified for dictionary values.
        Console.WriteLine();
        foreach( string s in icoll )
        {
            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, 
        ' and access it through the IDictionary generic interface.
        Dim openWith As IDictionary(Of String, String) = _
            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 icoll As ICollection(Of String) = 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  icoll
            Console.WriteLine("Value = {0}", s)
        Next s

        ' To get the keys alone, use the Keys property.
        icoll = openWith.Keys
        
        ' 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  icoll
            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.
'

注解

IDictionary<TKey,TValue>接口是键/值对的泛型集合的基接口。The IDictionary<TKey,TValue> interface is the base interface for generic collections of key/value pairs.

每个元素都是存储在对象中的键/值对 KeyValuePair<TKey,TValue>Each element is a key/value pair stored in a KeyValuePair<TKey,TValue> object.

每个对都必须有一个唯一键。Each pair must have a unique key. 实现在是否允许时可能有所不同 key nullImplementations can vary in whether they allow key to be null. 值可以为 null ,并且不必是唯一的。The value can be null and does not have to be unique. IDictionary<TKey,TValue>接口允许枚举包含的键和值,但不表示任何特定的排序顺序。The IDictionary<TKey,TValue> interface allows the contained keys and values to be enumerated, but it does not imply any particular sort order.

foreachC + + 中的 c # 语言 (的语句在 For Each Visual Basic 中, for each) 返回集合中元素的类型的对象。The foreach statement of the C# language (For Each in Visual Basic, for each in C++) returns an object of the type of the elements in the collection. 由于的每个元素 IDictionary<TKey,TValue> 都是键/值对,因此元素类型不是键的类型或值的类型。Since each element of the IDictionary<TKey,TValue> is a key/value pair, the element type is not the type of the key or the type of the value. 相反,元素类型为 KeyValuePair<TKey,TValue>Instead, the element type is KeyValuePair<TKey,TValue>. 例如:For example:

for each(KeyValuePair<int, String^> kvp in myDictionary)
{
    Console::WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value);
}
foreach (KeyValuePair<int, string> kvp in myDictionary)
{
    Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value);
}
For Each kvp As KeyValuePair(Of Integer, String) In myDictionary
    Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value)
Next kvp

foreach语句是枚举器周围的包装器,它仅允许从集合读取,而不是写入到集合中。The foreach statement is a wrapper around the enumerator, which only allows reading from, not writing to, the collection.

备注

因为键可以被继承并且其行为发生了更改,所以使用方法进行的比较无法保证其绝对唯一性 EqualsBecause keys can be inherited and their behavior changed, their absolute uniqueness cannot be guaranteed by comparisons using the Equals method.

实施者说明

实现类必须有一种方法来比较键。The implementing class must have a means to compare keys.

属性

Count

获取 ICollection<T> 中包含的元素数。Gets the number of elements contained in the ICollection<T>.

(继承自 ICollection<T>)
IsReadOnly

获取一个值,该值指示 ICollection<T> 是否为只读。Gets a value indicating whether the ICollection<T> is read-only.

(继承自 ICollection<T>)
Item[TKey]

获取或设置具有指定键的元素。Gets or sets the element with the specified key.

Keys

获取包含 ICollection<T> 的键的 IDictionary<TKey,TValue>Gets an ICollection<T> containing the keys of the IDictionary<TKey,TValue>.

Values

获取一个 ICollection<T>,它包含 IDictionary<TKey,TValue> 中的值。Gets an ICollection<T> containing the values in the IDictionary<TKey,TValue>.

方法

Add(T)

将某项添加到 ICollection<T> 中。Adds an item to the ICollection<T>.

(继承自 ICollection<T>)
Add(TKey, TValue)

IDictionary<TKey,TValue> 添加一个带有所提供的键和值的元素。Adds an element with the provided key and value to the IDictionary<TKey,TValue>.

Clear()

ICollection<T> 中移除所有项。Removes all items from the ICollection<T>.

(继承自 ICollection<T>)
Contains(T)

确定 ICollection<T> 是否包含特定值。Determines whether the ICollection<T> contains a specific value.

(继承自 ICollection<T>)
ContainsKey(TKey)

确定是否 IDictionary<TKey,TValue> 包含带有指定键的元素。Determines whether the IDictionary<TKey,TValue> contains an element with the specified key.

CopyTo(T[], Int32)

从特定的 ICollection<T> 索引开始,将 Array 的元素复制到一个 Array 中。Copies the elements of the ICollection<T> to an Array, starting at a particular Array index.

(继承自 ICollection<T>)
GetEnumerator()

返回循环访问集合的枚举数。Returns an enumerator that iterates through a collection.

(继承自 IEnumerable)
Remove(TKey)

IDictionary<TKey,TValue> 中移除包含指定键的元素。Removes the element with the specified key from the IDictionary<TKey,TValue>.

TryGetValue(TKey, TValue)

获取与指定键关联的值。Gets the value associated with the specified key.

扩展方法

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

尝试从 dictionary 中删除具有指定的 key 的值。Tries to remove the value with the specified key from the dictionary.

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

尝试将指定的 keyvalue 添加到 dictionaryTries to add the specified key and value to the dictionary.

ToImmutableArray<TSource>(IEnumerable<TSource>)

从指定的集合创建一个不可变数组。Creates an immutable array from the specified collection.

ToImmutableDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>)

通过向源键应用转换函数,从现有元素集合构造一个不可变字典。Constructs an immutable dictionary from an existing collection of elements, applying a transformation function to the source keys.

ToImmutableDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>)

基于对序列进行某种形式的转换来构造一个不可变字典。Constructs an immutable dictionary based on some transformation of a sequence.

ToImmutableDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>)

枚举并转换序列,然后生成其内容的不可变字典。Enumerates and transforms a sequence, and produces an immutable dictionary of its contents.

ToImmutableDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>, IEqualityComparer<TKey>)

枚举并转换序列,然后使用指定的键比较器生成其内容的不可变字典。Enumerates and transforms a sequence, and produces an immutable dictionary of its contents by using the specified key comparer.

ToImmutableDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>, IEqualityComparer<TKey>, IEqualityComparer<TValue>)

枚举并转换序列,然后使用指定的键和值比较器生成其内容的不可变字典。Enumerates and transforms a sequence, and produces an immutable dictionary of its contents by using the specified key and value comparers.

ToImmutableHashSet<TSource>(IEnumerable<TSource>)

枚举序列,并生成其内容的不可变哈希集。Enumerates a sequence and produces an immutable hash set of its contents.

ToImmutableHashSet<TSource>(IEnumerable<TSource>, IEqualityComparer<TSource>)

枚举序列,生成其内容的不可变哈希集,并为集类型使用指定的相等性比较器。Enumerates a sequence, produces an immutable hash set of its contents, and uses the specified equality comparer for the set type.

ToImmutableList<TSource>(IEnumerable<TSource>)

枚举序列,并生成其内容的不可变列表。Enumerates a sequence and produces an immutable list of its contents.

ToImmutableSortedDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>)

枚举并转换序列,然后生成其内容的不可变排序字典。Enumerates and transforms a sequence, and produces an immutable sorted dictionary of its contents.

ToImmutableSortedDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>, IComparer<TKey>)

枚举并转换序列,然后使用指定的键比较器生成其内容的不可变排序字典。Enumerates and transforms a sequence, and produces an immutable sorted dictionary of its contents by using the specified key comparer.

ToImmutableSortedDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>, IComparer<TKey>, IEqualityComparer<TValue>)

枚举并转换序列,然后使用指定的键和值比较器生成其内容的不可变排序字典。Enumerates and transforms a sequence, and produces an immutable sorted dictionary of its contents by using the specified key and value comparers.

ToImmutableSortedSet<TSource>(IEnumerable<TSource>)

枚举序列,并生成其内容的不可变排序集。Enumerates a sequence and produces an immutable sorted set of its contents.

ToImmutableSortedSet<TSource>(IEnumerable<TSource>, IComparer<TSource>)

枚举序列,生成其内容的不可变排序集,并使用指定的比较器。Enumerates a sequence, produces an immutable sorted set of its contents, and uses the specified comparer.

CopyToDataTable<T>(IEnumerable<T>)

在给定其泛型参数 TDataTable 的输入 DataRow 对象的情况下,返回包含 IEnumerable<T> 对象副本的 DataRowReturns a DataTable that contains copies of the DataRow objects, given an input IEnumerable<T> object where the generic parameter T is DataRow.

CopyToDataTable<T>(IEnumerable<T>, DataTable, LoadOption)

在给定其泛型参数 TDataRow 的输入 DataTable 对象的情况下,将 IEnumerable<T> 对象复制到指定的 DataRowCopies DataRow objects to the specified DataTable, given an input IEnumerable<T> object where the generic parameter T is DataRow.

CopyToDataTable<T>(IEnumerable<T>, DataTable, LoadOption, FillErrorEventHandler)

在给定其泛型参数 TDataRow 的输入 DataTable 对象的情况下,将 IEnumerable<T> 对象复制到指定的 DataRowCopies DataRow objects to the specified DataTable, given an input IEnumerable<T> object where the generic parameter T is DataRow.

Aggregate<TSource>(IEnumerable<TSource>, Func<TSource,TSource,TSource>)

对序列应用累加器函数。Applies an accumulator function over a sequence.

Aggregate<TSource,TAccumulate>(IEnumerable<TSource>, TAccumulate, Func<TAccumulate,TSource,TAccumulate>)

对序列应用累加器函数。Applies an accumulator function over a sequence. 将指定的种子值用作累加器初始值。The specified seed value is used as the initial accumulator value.

Aggregate<TSource,TAccumulate,TResult>(IEnumerable<TSource>, TAccumulate, Func<TAccumulate,TSource,TAccumulate>, Func<TAccumulate,TResult>)

对序列应用累加器函数。Applies an accumulator function over a sequence. 将指定的种子值用作累加器的初始值,并使用指定的函数选择结果值。The specified seed value is used as the initial accumulator value, and the specified function is used to select the result value.

All<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)

确定序列中的所有元素是否都满足条件。Determines whether all elements of a sequence satisfy a condition.

Any<TSource>(IEnumerable<TSource>)

确定序列是否包含任何元素。Determines whether a sequence contains any elements.

Any<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)

确定序列中是否存在任意一个元素满足条件。Determines whether any element of a sequence satisfies a condition.

Append<TSource>(IEnumerable<TSource>, TSource)

将一个值追加到序列末尾。Appends a value to the end of the sequence.

AsEnumerable<TSource>(IEnumerable<TSource>)

返回类型化为 IEnumerable<T> 的输入。Returns the input typed as IEnumerable<T>.

Average<TSource>(IEnumerable<TSource>, Func<TSource,Decimal>)

计算 Decimal 值序列的平均值,这些值可通过对输入序列的每个元素调用转换函数获得。Computes the average of a sequence of Decimal values that are obtained by invoking a transform function on each element of the input sequence.

Average<TSource>(IEnumerable<TSource>, Func<TSource,Double>)

计算 Double 值序列的平均值,这些值可通过对输入序列的每个元素调用转换函数获得。Computes the average of a sequence of Double values that are obtained by invoking a transform function on each element of the input sequence.

Average<TSource>(IEnumerable<TSource>, Func<TSource,Int32>)

计算 Int32 值序列的平均值,这些值可通过对输入序列的每个元素调用转换函数获得。Computes the average of a sequence of Int32 values that are obtained by invoking a transform function on each element of the input sequence.

Average<TSource>(IEnumerable<TSource>, Func<TSource,Int64>)

计算 Int64 值序列的平均值,这些值可通过对输入序列的每个元素调用转换函数获得。Computes the average of a sequence of Int64 values that are obtained by invoking a transform function on each element of the input sequence.

Average<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Decimal>>)

计算可以为 null 的 Decimal 值序列的平均值,这些值可通过对输入序列的每个元素调用转换函数获得。Computes the average of a sequence of nullable Decimal values that are obtained by invoking a transform function on each element of the input sequence.

Average<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Double>>)

计算可以为 null 的 Double 值序列的平均值,这些值可通过对输入序列的每个元素调用转换函数获得。Computes the average of a sequence of nullable Double values that are obtained by invoking a transform function on each element of the input sequence.

Average<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int32>>)

计算可以为 null 的 Int32 值序列的平均值,这些值可通过对输入序列的每个元素调用转换函数获得。Computes the average of a sequence of nullable Int32 values that are obtained by invoking a transform function on each element of the input sequence.

Average<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int64>>)

计算可以为 null 的 Int64 值序列的平均值,这些值可通过对输入序列的每个元素调用转换函数获得。Computes the average of a sequence of nullable Int64 values that are obtained by invoking a transform function on each element of the input sequence.

Average<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Single>>)

计算可以为 null 的 Single 值序列的平均值,这些值可通过对输入序列的每个元素调用转换函数获得。Computes the average of a sequence of nullable Single values that are obtained by invoking a transform function on each element of the input sequence.

Average<TSource>(IEnumerable<TSource>, Func<TSource,Single>)

计算 Single 值序列的平均值,这些值可通过对输入序列的每个元素调用转换函数获得。Computes the average of a sequence of Single values that are obtained by invoking a transform function on each element of the input sequence.

Cast<TResult>(IEnumerable)

IEnumerable 的元素强制转换为指定的类型。Casts the elements of an IEnumerable to the specified type.

Concat<TSource>(IEnumerable<TSource>, IEnumerable<TSource>)

连接两个序列。Concatenates two sequences.

Contains<TSource>(IEnumerable<TSource>, TSource)

通过使用默认的相等比较器确定序列是否包含指定的元素。Determines whether a sequence contains a specified element by using the default equality comparer.

Contains<TSource>(IEnumerable<TSource>, TSource, IEqualityComparer<TSource>)

通过使用指定的 IEqualityComparer<T> 确定序列是否包含指定的元素。Determines whether a sequence contains a specified element by using a specified IEqualityComparer<T>.

Count<TSource>(IEnumerable<TSource>)

返回序列中的元素数量。Returns the number of elements in a sequence.

Count<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)

返回表示在指定的序列中满足条件的元素数量的数字。Returns a number that represents how many elements in the specified sequence satisfy a condition.

DefaultIfEmpty<TSource>(IEnumerable<TSource>)

返回指定序列中的元素;如果序列为空,则返回单一实例集合中的类型参数的默认值。Returns the elements of the specified sequence or the type parameter's default value in a singleton collection if the sequence is empty.

DefaultIfEmpty<TSource>(IEnumerable<TSource>, TSource)

返回指定序列中的元素;如果序列为空,则返回单一实例集合中的指定值。Returns the elements of the specified sequence or the specified value in a singleton collection if the sequence is empty.

Distinct<TSource>(IEnumerable<TSource>)

通过使用默认的相等比较器对值进行比较,返回序列中的非重复元素。Returns distinct elements from a sequence by using the default equality comparer to compare values.

Distinct<TSource>(IEnumerable<TSource>, IEqualityComparer<TSource>)

通过使用指定的 IEqualityComparer<T> 对值进行比较,返回序列中的非重复元素。Returns distinct elements from a sequence by using a specified IEqualityComparer<T> to compare values.

ElementAt<TSource>(IEnumerable<TSource>, Int32)

返回序列中指定索引处的元素。Returns the element at a specified index in a sequence.

ElementAtOrDefault<TSource>(IEnumerable<TSource>, Int32)

返回序列中指定索引处的元素;如果索引超出范围,则返回默认值。Returns the element at a specified index in a sequence or a default value if the index is out of range.

Except<TSource>(IEnumerable<TSource>, IEnumerable<TSource>)

通过使用默认的相等比较器对值进行比较,生成两个序列的差集。Produces the set difference of two sequences by using the default equality comparer to compare values.

Except<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>)

通过使用指定的 IEqualityComparer<T> 对值进行比较,生成两个序列的差集。Produces the set difference of two sequences by using the specified IEqualityComparer<T> to compare values.

First<TSource>(IEnumerable<TSource>)

返回序列中的第一个元素。Returns the first element of a sequence.

First<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)

返回序列中满足指定条件的第一个元素。Returns the first element in a sequence that satisfies a specified condition.

FirstOrDefault<TSource>(IEnumerable<TSource>)

返回序列中的第一个元素;如果序列中不包含任何元素,则返回默认值。Returns the first element of a sequence, or a default value if the sequence contains no elements.

FirstOrDefault<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)

返回序列中满足条件的第一个元素;如果未找到这样的元素,则返回默认值。Returns the first element of the sequence that satisfies a condition or a default value if no such element is found.

GroupBy<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>)

根据指定的键选择器函数对序列中的元素进行分组。Groups the elements of a sequence according to a specified key selector function.

GroupBy<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>)

根据指定的键选择器函数对序列中的元素进行分组,并使用指定的比较器对键进行比较。Groups the elements of a sequence according to a specified key selector function and compares the keys by using a specified comparer.

GroupBy<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>)

根据指定的键选择器函数对序列中的元素进行分组,并且通过使用指定的函数对每个组中的元素进行投影。Groups the elements of a sequence according to a specified key selector function and projects the elements for each group by using a specified function.

GroupBy<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, IEqualityComparer<TKey>)

根据键选择器函数对序列中的元素进行分组。Groups the elements of a sequence according to a key selector function. 通过使用比较器对键进行比较,并且通过使用指定的函数对每个组的元素进行投影。The keys are compared by using a comparer and each group's elements are projected by using a specified function.

GroupBy<TSource,TKey,TResult>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TKey,IEnumerable<TSource>,TResult>)

根据指定的键选择器函数对序列中的元素进行分组,并且从每个组及其键中创建结果值。Groups the elements of a sequence according to a specified key selector function and creates a result value from each group and its key.

GroupBy<TSource,TKey,TResult>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TKey,IEnumerable<TSource>,TResult>, IEqualityComparer<TKey>)

根据指定的键选择器函数对序列中的元素进行分组,并且从每个组及其键中创建结果值。Groups the elements of a sequence according to a specified key selector function and creates a result value from each group and its key. 通过使用指定的比较器对键进行比较。The keys are compared by using a specified comparer.

GroupBy<TSource,TKey,TElement,TResult>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, Func<TKey,IEnumerable<TElement>,TResult>)

根据指定的键选择器函数对序列中的元素进行分组,并且从每个组及其键中创建结果值。Groups the elements of a sequence according to a specified key selector function and creates a result value from each group and its key. 通过使用指定的函数对每个组的元素进行投影。The elements of each group are projected by using a specified function.

GroupBy<TSource,TKey,TElement,TResult>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, Func<TKey,IEnumerable<TElement>,TResult>, IEqualityComparer<TKey>)

根据指定的键选择器函数对序列中的元素进行分组,并且从每个组及其键中创建结果值。Groups the elements of a sequence according to a specified key selector function and creates a result value from each group and its key. 通过使用指定的比较器对键值进行比较,并且通过使用指定的函数对每个组的元素进行投影。Key values are compared by using a specified comparer, and the elements of each group are projected by using a specified function.

GroupJoin<TOuter,TInner,TKey,TResult>(IEnumerable<TOuter>, IEnumerable<TInner>, Func<TOuter,TKey>, Func<TInner,TKey>, Func<TOuter,IEnumerable<TInner>,TResult>)

基于键值等同性对两个序列的元素进行关联,并对结果进行分组。Correlates the elements of two sequences based on equality of keys and groups the results. 使用默认的相等比较器对键进行比较。The default equality comparer is used to compare keys.

GroupJoin<TOuter,TInner,TKey,TResult>(IEnumerable<TOuter>, IEnumerable<TInner>, Func<TOuter,TKey>, Func<TInner,TKey>, Func<TOuter,IEnumerable<TInner>,TResult>, IEqualityComparer<TKey>)

基于键值等同性对两个序列的元素进行关联,并对结果进行分组。Correlates the elements of two sequences based on key equality and groups the results. 使用指定的 IEqualityComparer<T> 对键进行比较。A specified IEqualityComparer<T> is used to compare keys.

Intersect<TSource>(IEnumerable<TSource>, IEnumerable<TSource>)

通过使用默认的相等比较器对值进行比较,生成两个序列的交集。Produces the set intersection of two sequences by using the default equality comparer to compare values.

Intersect<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>)

通过使用指定的 IEqualityComparer<T> 对值进行比较,生成两个序列的交集。Produces the set intersection of two sequences by using the specified IEqualityComparer<T> to compare values.

Join<TOuter,TInner,TKey,TResult>(IEnumerable<TOuter>, IEnumerable<TInner>, Func<TOuter,TKey>, Func<TInner,TKey>, Func<TOuter,TInner,TResult>)

基于匹配键对两个序列的元素进行关联。Correlates the elements of two sequences based on matching keys. 使用默认的相等比较器对键进行比较。The default equality comparer is used to compare keys.

Join<TOuter,TInner,TKey,TResult>(IEnumerable<TOuter>, IEnumerable<TInner>, Func<TOuter,TKey>, Func<TInner,TKey>, Func<TOuter,TInner,TResult>, IEqualityComparer<TKey>)

基于匹配键对两个序列的元素进行关联。Correlates the elements of two sequences based on matching keys. 使用指定的 IEqualityComparer<T> 对键进行比较。A specified IEqualityComparer<T> is used to compare keys.

Last<TSource>(IEnumerable<TSource>)

返回序列的最后一个元素。Returns the last element of a sequence.

Last<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)

返回序列中满足指定条件的最后一个元素。Returns the last element of a sequence that satisfies a specified condition.

LastOrDefault<TSource>(IEnumerable<TSource>)

返回序列中的最后一个元素;如果序列中不包含任何元素,则返回默认值。Returns the last element of a sequence, or a default value if the sequence contains no elements.

LastOrDefault<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)

返回序列中满足条件的最后一个元素;如果未找到这样的元素,则返回默认值。Returns the last element of a sequence that satisfies a condition or a default value if no such element is found.

LongCount<TSource>(IEnumerable<TSource>)

返回表示序列中元素总数的 Int64Returns an Int64 that represents the total number of elements in a sequence.

LongCount<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)

返回表示序列中满足条件的元素的数量的 Int64Returns an Int64 that represents how many elements in a sequence satisfy a condition.

Max<TSource>(IEnumerable<TSource>)

返回泛型序列中的最大值。Returns the maximum value in a generic sequence.

Max<TSource>(IEnumerable<TSource>, Func<TSource,Decimal>)

对序列中的每个元素调用转换函数,并返回最大的 Decimal 值。Invokes a transform function on each element of a sequence and returns the maximum Decimal value.

Max<TSource>(IEnumerable<TSource>, Func<TSource,Double>)

对序列中的每个元素调用转换函数,并返回最大的 Double 值。Invokes a transform function on each element of a sequence and returns the maximum Double value.

Max<TSource>(IEnumerable<TSource>, Func<TSource,Int32>)

对序列中的每个元素调用转换函数,并返回最大的 Int32 值。Invokes a transform function on each element of a sequence and returns the maximum Int32 value.

Max<TSource>(IEnumerable<TSource>, Func<TSource,Int64>)

对序列中的每个元素调用转换函数,并返回最大的 Int64 值。Invokes a transform function on each element of a sequence and returns the maximum Int64 value.

Max<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Decimal>>)

对序列中的每个元素调用转换函数,并返回可以为 null 的最大的 Decimal 值。Invokes a transform function on each element of a sequence and returns the maximum nullable Decimal value.

Max<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Double>>)

对序列中的每个元素调用转换函数,并返回可以为 null 的最大的 Double 值。Invokes a transform function on each element of a sequence and returns the maximum nullable Double value.

Max<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int32>>)

对序列中的每个元素调用转换函数,并返回可以为 null 的最大的 Int32 值。Invokes a transform function on each element of a sequence and returns the maximum nullable Int32 value.

Max<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int64>>)

对序列中的每个元素调用转换函数,并返回可以为 null 的最大的 Int64 值。Invokes a transform function on each element of a sequence and returns the maximum nullable Int64 value.

Max<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Single>>)

对序列中的每个元素调用转换函数,并返回可以为 null 的最大的 Single 值。Invokes a transform function on each element of a sequence and returns the maximum nullable Single value.

Max<TSource>(IEnumerable<TSource>, Func<TSource,Single>)

对序列中的每个元素调用转换函数,并返回最大的 Single 值。Invokes a transform function on each element of a sequence and returns the maximum Single value.

Max<TSource,TResult>(IEnumerable<TSource>, Func<TSource,TResult>)

对序列中的每个元素调用转换函数,并返回最大结果值。Invokes a transform function on each element of a generic sequence and returns the maximum resulting value.

Min<TSource>(IEnumerable<TSource>)

返回泛型序列中的最小值。Returns the minimum value in a generic sequence.

Min<TSource>(IEnumerable<TSource>, Func<TSource,Decimal>)

对序列中的每个元素调用转换函数,并返回最小的 Decimal 值。Invokes a transform function on each element of a sequence and returns the minimum Decimal value.

Min<TSource>(IEnumerable<TSource>, Func<TSource,Double>)

对序列中的每个元素调用转换函数,并返回最小的 Double 值。Invokes a transform function on each element of a sequence and returns the minimum Double value.

Min<TSource>(IEnumerable<TSource>, Func<TSource,Int32>)

对序列中的每个元素调用转换函数,并返回最小的 Int32 值。Invokes a transform function on each element of a sequence and returns the minimum Int32 value.

Min<TSource>(IEnumerable<TSource>, Func<TSource,Int64>)

对序列中的每个元素调用转换函数,并返回最小的 Int64 值。Invokes a transform function on each element of a sequence and returns the minimum Int64 value.

Min<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Decimal>>)

对序列中的每个元素调用转换函数,并返回可以为 null 的最小的 Decimal 值。Invokes a transform function on each element of a sequence and returns the minimum nullable Decimal value.

Min<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Double>>)

对序列中的每个元素调用转换函数,并返回可以为 null 的最小的 Double 值。Invokes a transform function on each element of a sequence and returns the minimum nullable Double value.

Min<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int32>>)

对序列中的每个元素调用转换函数,并返回可以为 null 的最小的 Int32 值。Invokes a transform function on each element of a sequence and returns the minimum nullable Int32 value.

Min<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int64>>)

对序列中的每个元素调用转换函数,并返回可以为 null 的最小的 Int64 值。Invokes a transform function on each element of a sequence and returns the minimum nullable Int64 value.

Min<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Single>>)

对序列中的每个元素调用转换函数,并返回可以为 null 的最小的 Single 值。Invokes a transform function on each element of a sequence and returns the minimum nullable Single value.

Min<TSource>(IEnumerable<TSource>, Func<TSource,Single>)

对序列中的每个元素调用转换函数,并返回最小的 Single 值。Invokes a transform function on each element of a sequence and returns the minimum Single value.

Min<TSource,TResult>(IEnumerable<TSource>, Func<TSource,TResult>)

对序列中的每个元素调用转换函数,并返回最小结果值。Invokes a transform function on each element of a generic sequence and returns the minimum resulting value.

OfType<TResult>(IEnumerable)

根据指定类型筛选 IEnumerable 的元素。Filters the elements of an IEnumerable based on a specified type.

OrderBy<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>)

根据键按升序对序列的元素进行排序。Sorts the elements of a sequence in ascending order according to a key.

OrderBy<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IComparer<TKey>)

使用指定的比较器按升序对序列的元素进行排序。Sorts the elements of a sequence in ascending order by using a specified comparer.

OrderByDescending<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>)

根据键按降序对序列的元素进行排序。Sorts the elements of a sequence in descending order according to a key.

OrderByDescending<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IComparer<TKey>)

使用指定的比较器按降序对序列的元素排序。Sorts the elements of a sequence in descending order by using a specified comparer.

Prepend<TSource>(IEnumerable<TSource>, TSource)

向序列的开头添加值。Adds a value to the beginning of the sequence.

Reverse<TSource>(IEnumerable<TSource>)

反转序列中元素的顺序。Inverts the order of the elements in a sequence.

Select<TSource,TResult>(IEnumerable<TSource>, Func<TSource,TResult>)

将序列中的每个元素投影到新表单。Projects each element of a sequence into a new form.

Select<TSource,TResult>(IEnumerable<TSource>, Func<TSource,Int32,TResult>)

通过合并元素的索引,将序列的每个元素投影到新窗体中。Projects each element of a sequence into a new form by incorporating the element's index.

SelectMany<TSource,TResult>(IEnumerable<TSource>, Func<TSource,IEnumerable<TResult>>)

将序列的每个元素投影到 IEnumerable<T> 并将结果序列合并为一个序列。Projects each element of a sequence to an IEnumerable<T> and flattens the resulting sequences into one sequence.

SelectMany<TSource,TResult>(IEnumerable<TSource>, Func<TSource,Int32,IEnumerable<TResult>>)

将序列的每个元素投影到 IEnumerable<T> 并将结果序列合并为一个序列。Projects each element of a sequence to an IEnumerable<T>, and flattens the resulting sequences into one sequence. 每个源元素的索引用于该元素的投影表。The index of each source element is used in the projected form of that element.

SelectMany<TSource,TCollection,TResult>(IEnumerable<TSource>, Func<TSource,IEnumerable<TCollection>>, Func<TSource,TCollection,TResult>)

将序列的每个元素投影到 IEnumerable<T>,并将结果序列合并为一个序列,并对其中每个元素调用结果选择器函数。Projects each element of a sequence to an IEnumerable<T>, flattens the resulting sequences into one sequence, and invokes a result selector function on each element therein.

SelectMany<TSource,TCollection,TResult>(IEnumerable<TSource>, Func<TSource,Int32,IEnumerable<TCollection>>, Func<TSource,TCollection,TResult>)

将序列的每个元素投影到 IEnumerable<T>,并将结果序列合并为一个序列,并对其中每个元素调用结果选择器函数。Projects each element of a sequence to an IEnumerable<T>, flattens the resulting sequences into one sequence, and invokes a result selector function on each element therein. 每个源元素的索引用于该元素的中间投影表。The index of each source element is used in the intermediate projected form of that element.

SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>)

通过使用相应类型的默认相等比较器对序列的元素进行比较,以确定两个序列是否相等。Determines whether two sequences are equal by comparing the elements by using the default equality comparer for their type.

SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>)

通过使用指定的 IEqualityComparer<T> 来比较两个序列的元素,以确定这两个序列是否相等。Determines whether two sequences are equal by comparing their elements by using a specified IEqualityComparer<T>.

Single<TSource>(IEnumerable<TSource>)

返回序列的唯一元素;如果该序列并非恰好包含一个元素,则会引发异常。Returns the only element of a sequence, and throws an exception if there is not exactly one element in the sequence.

Single<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)

返回序列中满足指定条件的唯一元素;如果有多个这样的元素存在,则会引发异常。Returns the only element of a sequence that satisfies a specified condition, and throws an exception if more than one such element exists.

SingleOrDefault<TSource>(IEnumerable<TSource>)

返回序列中的唯一元素;如果该序列为空,则返回默认值;如果该序列包含多个元素,此方法将引发异常。Returns the only element of a sequence, or a default value if the sequence is empty; this method throws an exception if there is more than one element in the sequence.

SingleOrDefault<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)

返回序列中满足指定条件的唯一元素;如果这类元素不存在,则返回默认值;如果有多个元素满足该条件,此方法将引发异常。Returns the only element of a sequence that satisfies a specified condition or a default value if no such element exists; this method throws an exception if more than one element satisfies the condition.

Skip<TSource>(IEnumerable<TSource>, Int32)

跳过序列中指定数量的元素,然后返回剩余的元素。Bypasses a specified number of elements in a sequence and then returns the remaining elements.

SkipLast<TSource>(IEnumerable<TSource>, Int32)

返回一个新的可枚举集合,它包含 source 中的元素,但省略了源集合中的 count 个元素。Returns a new enumerable collection that contains the elements from source with the last count elements of the source collection omitted.

SkipWhile<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)

如果指定的条件为 true,则跳过序列中的元素,然后返回剩余的元素。Bypasses elements in a sequence as long as a specified condition is true and then returns the remaining elements.

SkipWhile<TSource>(IEnumerable<TSource>, Func<TSource,Int32,Boolean>)

如果指定的条件为 true,则跳过序列中的元素,然后返回剩余的元素。Bypasses elements in a sequence as long as a specified condition is true and then returns the remaining elements. 将在谓词函数的逻辑中使用元素的索引。The element's index is used in the logic of the predicate function.

Sum<TSource>(IEnumerable<TSource>, Func<TSource,Decimal>)

计算 Decimal 值序列的总和,这些值可通过对输入序列中的每个元素调用转换函数获得。Computes the sum of the sequence of Decimal values that are obtained by invoking a transform function on each element of the input sequence.

Sum<TSource>(IEnumerable<TSource>, Func<TSource,Double>)

计算 Double 值序列的总和,这些值可通过对输入序列中的每个元素调用转换函数获得。Computes the sum of the sequence of Double values that are obtained by invoking a transform function on each element of the input sequence.

Sum<TSource>(IEnumerable<TSource>, Func<TSource,Int32>)

计算 Int32 值序列的总和,这些值可通过对输入序列中的每个元素调用转换函数获得。Computes the sum of the sequence of Int32 values that are obtained by invoking a transform function on each element of the input sequence.

Sum<TSource>(IEnumerable<TSource>, Func<TSource,Int64>)

计算 Int64 值序列的总和,这些值可通过对输入序列中的每个元素调用转换函数获得。Computes the sum of the sequence of Int64 values that are obtained by invoking a transform function on each element of the input sequence.

Sum<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Decimal>>)

计算可以为 null 的 Decimal 值序列的总和,这些值可通过对输入序列的每个元素调用转换函数获得。Computes the sum of the sequence of nullable Decimal values that are obtained by invoking a transform function on each element of the input sequence.

Sum<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Double>>)

计算可以为 null 的 Double 值序列的总和,这些值可通过对输入序列的每个元素调用转换函数获得。Computes the sum of the sequence of nullable Double values that are obtained by invoking a transform function on each element of the input sequence.

Sum<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int32>>)

计算可以为 null 的 Int32 值序列的总和,这些值可通过对输入序列的每个元素调用转换函数获得。Computes the sum of the sequence of nullable Int32 values that are obtained by invoking a transform function on each element of the input sequence.

Sum<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int64>>)

计算可以为 null 的 Int64 值序列的总和,这些值可通过对输入序列的每个元素调用转换函数获得。Computes the sum of the sequence of nullable Int64 values that are obtained by invoking a transform function on each element of the input sequence.

Sum<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Single>>)

计算可以为 null 的 Single 值序列的总和,这些值可通过对输入序列的每个元素调用转换函数获得。Computes the sum of the sequence of nullable Single values that are obtained by invoking a transform function on each element of the input sequence.

Sum<TSource>(IEnumerable<TSource>, Func<TSource,Single>)

计算 Single 值序列的总和,这些值可通过对输入序列中的每个元素调用转换函数获得。Computes the sum of the sequence of Single values that are obtained by invoking a transform function on each element of the input sequence.

Take<TSource>(IEnumerable<TSource>, Int32)

从序列的开头返回指定数量的相邻元素。Returns a specified number of contiguous elements from the start of a sequence.

TakeLast<TSource>(IEnumerable<TSource>, Int32)

返回一个新的可枚举集合,它包含 count 中的最后 source 个元素。Returns a new enumerable collection that contains the last count elements from source.

TakeWhile<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)

只要指定的条件为 true,就会返回序列的元素。Returns elements from a sequence as long as a specified condition is true.

TakeWhile<TSource>(IEnumerable<TSource>, Func<TSource,Int32,Boolean>)

只要指定的条件为 true,就会返回序列的元素。Returns elements from a sequence as long as a specified condition is true. 将在谓词函数的逻辑中使用元素的索引。The element's index is used in the logic of the predicate function.

ToArray<TSource>(IEnumerable<TSource>)

IEnumerable<T> 中创建数组。Creates an array from a IEnumerable<T>.

ToDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>)

根据指定的键选择器函数,从 IEnumerable<T> 创建一个 Dictionary<TKey,TValue>Creates a Dictionary<TKey,TValue> from an IEnumerable<T> according to a specified key selector function.

ToDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>)

根据指定的键选择器函数和键比较器,从 IEnumerable<T> 创建一个 Dictionary<TKey,TValue>Creates a Dictionary<TKey,TValue> from an IEnumerable<T> according to a specified key selector function and key comparer.

ToDictionary<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>)

根据指定的键选择器和元素选择器函数,从 IEnumerable<T> 创建一个 Dictionary<TKey,TValue>Creates a Dictionary<TKey,TValue> from an IEnumerable<T> according to specified key selector and element selector functions.

ToDictionary<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, IEqualityComparer<TKey>)

根据指定的键选择器函数、比较器和元素选择器函数,从 IEnumerable<T> 创建一个 Dictionary<TKey,TValue>Creates a Dictionary<TKey,TValue> from an IEnumerable<T> according to a specified key selector function, a comparer, and an element selector function.

ToHashSet<TSource>(IEnumerable<TSource>)

IEnumerable<T> 创建一个 HashSet<T>Creates a HashSet<T> from an IEnumerable<T>.

ToHashSet<TSource>(IEnumerable<TSource>, IEqualityComparer<TSource>)

使用 comparer 通过 IEnumerable<T> 创建 HashSet<T>,以用于比较键。Creates a HashSet<T> from an IEnumerable<T> using the comparer to compare keys.

ToList<TSource>(IEnumerable<TSource>)

IEnumerable<T> 创建一个 List<T>Creates a List<T> from an IEnumerable<T>.

ToLookup<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>)

根据指定的键选择器函数,从 IEnumerable<T> 创建一个 Lookup<TKey,TElement>Creates a Lookup<TKey,TElement> from an IEnumerable<T> according to a specified key selector function.

ToLookup<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>)

根据指定的键选择器函数和键比较器,从 IEnumerable<T> 创建一个 Lookup<TKey,TElement>Creates a Lookup<TKey,TElement> from an IEnumerable<T> according to a specified key selector function and key comparer.

ToLookup<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>)

根据指定的键选择器和元素选择器函数,从 IEnumerable<T> 创建一个 Lookup<TKey,TElement>Creates a Lookup<TKey,TElement> from an IEnumerable<T> according to specified key selector and element selector functions.

ToLookup<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, IEqualityComparer<TKey>)

根据指定的键选择器函数、比较器和元素选择器函数,从 IEnumerable<T> 创建一个 Lookup<TKey,TElement>Creates a Lookup<TKey,TElement> from an IEnumerable<T> according to a specified key selector function, a comparer and an element selector function.

Union<TSource>(IEnumerable<TSource>, IEnumerable<TSource>)

通过使用默认的相等比较器,生成两个序列的并集。Produces the set union of two sequences by using the default equality comparer.

Union<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>)

通过使用指定的 IEqualityComparer<T> 生成两个序列的并集。Produces the set union of two sequences by using a specified IEqualityComparer<T>.

Where<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)

基于谓词筛选值序列。Filters a sequence of values based on a predicate.

Where<TSource>(IEnumerable<TSource>, Func<TSource,Int32,Boolean>)

基于谓词筛选值序列。Filters a sequence of values based on a predicate. 将在谓词函数的逻辑中使用每个元素的索引。Each element's index is used in the logic of the predicate function.

Zip<TFirst,TSecond>(IEnumerable<TFirst>, IEnumerable<TSecond>)

使用两个指定序列中的元素生成元组序列。Produces a sequence of tuples with elements from the two specified sequences.

Zip<TFirst,TSecond,TResult>(IEnumerable<TFirst>, IEnumerable<TSecond>, Func<TFirst,TSecond,TResult>)

将指定函数应用于两个序列的对应元素,以生成结果序列。Applies a specified function to the corresponding elements of two sequences, producing a sequence of the results.

AsParallel(IEnumerable)

启用查询的并行化。Enables parallelization of a query.

AsParallel<TSource>(IEnumerable<TSource>)

启用查询的并行化。Enables parallelization of a query.

AsQueryable(IEnumerable)

IEnumerable 转换为 IQueryableConverts an IEnumerable to an IQueryable.

AsQueryable<TElement>(IEnumerable<TElement>)

将泛型 IEnumerable<T> 转换为泛型 IQueryable<T>Converts a generic IEnumerable<T> to a generic IQueryable<T>.

Ancestors<T>(IEnumerable<T>)

返回元素集合,其中包含源集合中每个节点的上级。Returns a collection of elements that contains the ancestors of every node in the source collection.

Ancestors<T>(IEnumerable<T>, XName)

返回经过筛选的元素集合,其中包含源集合中每个节点的上级。Returns a filtered collection of elements that contains the ancestors of every node in the source collection. 集合中仅包括具有匹配 XName 的元素。Only elements that have a matching XName are included in the collection.

DescendantNodes<T>(IEnumerable<T>)

返回源集合中每个文档和元素的子代节点的集合。Returns a collection of the descendant nodes of every document and element in the source collection.

Descendants<T>(IEnumerable<T>)

返回元素集合,其中包含源集合中每个元素和文档的子代元素。Returns a collection of elements that contains the descendant elements of every element and document in the source collection.

Descendants<T>(IEnumerable<T>, XName)

返回经过筛选的元素集合,其中包含源集合中每个元素和文档的子代元素。Returns a filtered collection of elements that contains the descendant elements of every element and document in the source collection. 集合中仅包括具有匹配 XName 的元素。Only elements that have a matching XName are included in the collection.

Elements<T>(IEnumerable<T>)

返回源集合中每个元素和文档的子元素的集合。Returns a collection of the child elements of every element and document in the source collection.

Elements<T>(IEnumerable<T>, XName)

返回源集合中经过筛选的每个元素和文档的子元素集合。Returns a filtered collection of the child elements of every element and document in the source collection. 集合中仅包括具有匹配 XName 的元素。Only elements that have a matching XName are included in the collection.

InDocumentOrder<T>(IEnumerable<T>)

返回节点集合(其中包含源集合中的所有节点),并按文档顺序排列。Returns a collection of nodes that contains all nodes in the source collection, sorted in document order.

Nodes<T>(IEnumerable<T>)

返回源集合中每个文档和元素的子节点集合。Returns a collection of the child nodes of every document and element in the source collection.

Remove<T>(IEnumerable<T>)

将源集合中的每个节点从其父节点中移除。Removes every node in the source collection from its parent node.

适用于

另请参阅