IEnumerable<T> 接口

定义

命名空间:: System.Collections.Generic

程序集:: System.Runtime.dll, mscorlib.dll, netstandard.dll

公开枚举数，该枚举数支持在指定类型的集合上进行简单迭代。Exposes the enumerator, which supports a simple iteration over a collection of a specified type.

generic <typename T>
public interface class IEnumerable : System::Collections::IEnumerable

public interface IEnumerable<out T> : System.Collections.IEnumerable

type seq<'T> = interface
    interface IEnumerable

Public Interface IEnumerable(Of Out T)
Implements IEnumerable

类型参数

T

要枚举的对象的类型。The type of objects to enumerate.

这是协变类型参数。即，可以使用指定的类型，也可以使用派生程度较高的任何类型。有关协变和逆变的详细信息，请参阅泛型中的协变和逆变。

派生: Microsoft.Build.BuildEngine.ToolsetCollection

Microsoft.Build.BuildEngine.ToolsetCollection

Microsoft.Extensions.Configuration.Memory.MemoryConfigurationProvider

Microsoft.Extensions.DependencyInjection.IServiceCollection

Microsoft.Extensions.DependencyInjection.IServiceCollection

更多…

实现: IEnumerable

示例

下面的示例演示如何实现 IEnumerable<T> 接口以及如何使用该实现创建 LINQ 查询。The following example demonstrates how to implement the IEnumerable<T> interface and how to use that implementation to create a LINQ query. 在实现 IEnumerable<T>时，还必须实现 IEnumerator<T> 或，只能对C#使用yield关键字。When you implement IEnumerable<T>, you must also implement IEnumerator<T> or, for C# only, you can use the yield keyword. 实现 IEnumerator<T> 还需要实现 IDisposable，这将在本示例中看到。Implementing IEnumerator<T> also requires IDisposable to be implemented, which you will see in this example.

using System;
using System.IO;
using System.Collections;
using System.Collections.Generic;
using System.Linq;

public class App
{
    // Excercise the Iterator and show that it's more
    // performant.
    public static void Main()
    {
        TestStreamReaderEnumerable();
        Console.WriteLine("---");
        TestReadingFile();
    }

    public static void TestStreamReaderEnumerable()
    {
        // Check the memory before the iterator is used.
        long memoryBefore = GC.GetTotalMemory(true);
      IEnumerable<String> stringsFound;
        // Open a file with the StreamReaderEnumerable and check for a string.
      try {
         stringsFound =
               from line in new StreamReaderEnumerable(@"c:\temp\tempFile.txt")
               where line.Contains("string to search for")
               select line;
         Console.WriteLine("Found: " + stringsFound.Count());
      }
      catch (FileNotFoundException) {
         Console.WriteLine(@"This example requires a file named C:\temp\tempFile.txt.");
         return;
      }

        // Check the memory after the iterator and output it to the console.
        long memoryAfter = GC.GetTotalMemory(false);
        Console.WriteLine("Memory Used With Iterator = \t"
            + string.Format(((memoryAfter - memoryBefore) / 1000).ToString(), "n") + "kb");
    }

    public static void TestReadingFile()
    {
        long memoryBefore = GC.GetTotalMemory(true);
      StreamReader sr;
      try {
         sr = File.OpenText("c:\\temp\\tempFile.txt");
      }
      catch (FileNotFoundException) {
         Console.WriteLine(@"This example requires a file named C:\temp\tempFile.txt.");
         return;
      }

        // Add the file contents to a generic list of strings.
        List<string> fileContents = new List<string>();
        while (!sr.EndOfStream) {
            fileContents.Add(sr.ReadLine());
        }

        // Check for the string.
        var stringsFound = 
            from line in fileContents
            where line.Contains("string to search for")
            select line;

        sr.Close();
        Console.WriteLine("Found: " + stringsFound.Count());

        // Check the memory after when the iterator is not used, and output it to the console.
        long memoryAfter = GC.GetTotalMemory(false);
        Console.WriteLine("Memory Used Without Iterator = \t" + 
            string.Format(((memoryAfter - memoryBefore) / 1000).ToString(), "n") + "kb");
    }
}

// A custom class that implements IEnumerable(T). When you implement IEnumerable(T), 
// you must also implement IEnumerable and IEnumerator(T).
public class StreamReaderEnumerable : IEnumerable<string>
{
    private string _filePath;
    public StreamReaderEnumerable(string filePath)
    {
        _filePath = filePath;
    }

    // Must implement GetEnumerator, which returns a new StreamReaderEnumerator.
    public IEnumerator<string> GetEnumerator()
    {
        return new StreamReaderEnumerator(_filePath);
    }

    // Must also implement IEnumerable.GetEnumerator, but implement as a private method.
    private IEnumerator GetEnumerator1()
    {
        return this.GetEnumerator();
    }
    IEnumerator IEnumerable.GetEnumerator()
    {
        return GetEnumerator1();
    }
}

// When you implement IEnumerable(T), you must also implement IEnumerator(T), 
// which will walk through the contents of the file one line at a time.
// Implementing IEnumerator(T) requires that you implement IEnumerator and IDisposable.
public class StreamReaderEnumerator : IEnumerator<string>
{
    private StreamReader _sr;
    public StreamReaderEnumerator(string filePath)
    {
        _sr = new StreamReader(filePath);
    }

    private string _current;
    // Implement the IEnumerator(T).Current publicly, but implement 
    // IEnumerator.Current, which is also required, privately.
    public string Current
    {

        get
        {
            if (_sr == null || _current == null)
            {
                throw new InvalidOperationException();
            }

            return _current;
        }
    }

    private object Current1
    {

        get { return this.Current; }
    }

    object IEnumerator.Current
    {
        get { return Current1; }
    }

    // Implement MoveNext and Reset, which are required by IEnumerator.
    public bool MoveNext()
    {
        _current = _sr.ReadLine();
        if (_current == null)
            return false;
        return true;
    }

    public void Reset()
    {
        _sr.DiscardBufferedData();
        _sr.BaseStream.Seek(0, SeekOrigin.Begin);
        _current = null;
    }

    // Implement IDisposable, which is also implemented by IEnumerator(T).
    private bool disposedValue = false;
    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    protected virtual void Dispose(bool disposing)
    {
        if (!this.disposedValue)
        {
            if (disposing)
            {
                // Dispose of managed resources.
            }
            _current = null;
            if (_sr != null) {
               _sr.Close();
               _sr.Dispose();
            }
        }

        this.disposedValue = true;
    }

     ~StreamReaderEnumerator()
    {
        Dispose(false);
    }
}
// This example displays output similar to the following:
//       Found: 2
//       Memory Used With Iterator =     33kb
//       ---
//       Found: 2
//       Memory Used Without Iterator =  206kb

Imports System.IO
Imports System.Collections
Imports System.Collections.Generic
Imports System.Linq

Public Module App
   ' Excercise the Iterator and show that it's more performant.
   Public Sub Main()
      TestStreamReaderEnumerable()
      Console.WriteLine("---")
      TestReadingFile()
   End Sub

   Public Sub TestStreamReaderEnumerable()
        ' Check the memory before the iterator is used.
        Dim memoryBefore As Long = GC.GetTotalMemory(true)
      Dim stringsFound As IEnumerable(Of String)
        ' Open a file with the StreamReaderEnumerable and check for a string.
      Try
         stringsFound =
               from line in new StreamReaderEnumerable("c:\temp\tempFile.txt")
               where line.Contains("string to search for")
               select line
         Console.WriteLine("Found: {0}", stringsFound.Count())
      Catch e As FileNotFoundException
         Console.WriteLine("This example requires a file named C:\temp\tempFile.txt.")
         Return
      End Try

        ' Check the memory after the iterator and output it to the console.
        Dim memoryAfter As Long = GC.GetTotalMemory(false)
        Console.WriteLine("Memory Used with Iterator = {1}{0} kb",
                        (memoryAfter - memoryBefore)\1000, vbTab)
   End Sub

   Public Sub TestReadingFile()
        Dim memoryBefore As Long = GC.GetTotalMemory(true)
      Dim sr As StreamReader
      Try
         sr = File.OpenText("c:\temp\tempFile.txt")
      Catch e As FileNotFoundException
         Console.WriteLine("This example requires a file named C:\temp\tempFile.txt.")
         Return
      End Try

        ' Add the file contents to a generic list of strings.
        Dim fileContents As New List(Of String)()
        Do While Not sr.EndOfStream
            fileContents.Add(sr.ReadLine())
      Loop

        ' Check for the string.
        Dim stringsFound =
            from line in fileContents
            where line.Contains("string to search for")
            select line

      sr.Close()
      Console.WriteLine("Found: {0}", stringsFound.Count())

        ' Check the memory after when the iterator is not used, and output it to the console.
        Dim memoryAfter As Long = GC.GetTotalMemory(False)
        Console.WriteLine("Memory Used without Iterator = {1}{0} kb",
                        (memoryAfter - memoryBefore)\1000, vbTab)
   End Sub
End Module

' A custom class that implements IEnumerable(T). When you implement IEnumerable(T), 
' you must also implement IEnumerable and IEnumerator(T).
Public Class StreamReaderEnumerable : Implements IEnumerable(Of String)
    Private _filePath As String
    
    Public Sub New(filePath As String)
        _filePath = filePath
    End Sub

    ' Must implement GetEnumerator, which returns a new StreamReaderEnumerator.
    Public Function GetEnumerator() As IEnumerator(Of String) _
          Implements IEnumerable(Of String).GetEnumerator
        Return New StreamReaderEnumerator(_filePath)
    End Function

    ' Must also implement IEnumerable.GetEnumerator, but implement as a private method.
    Private Function GetEnumerator1() As IEnumerator _
          Implements IEnumerable.GetEnumerator
        Return Me.GetEnumerator()
    End Function
End Class

' When you implement IEnumerable(T), you must also implement IEnumerator(T), 
' which will walk through the contents of the file one line at a time.
' Implementing IEnumerator(T) requires that you implement IEnumerator and IDisposable.
Public Class StreamReaderEnumerator : Implements IEnumerator(Of String)
    Private _sr As StreamReader
    
    Public Sub New(filePath As String)
        _sr = New StreamReader(filePath)
    End Sub

    Private _current As String

    ' Implement the IEnumerator(T).Current Publicly, but implement 
    ' IEnumerator.Current, which is also required, privately.
    Public ReadOnly Property Current As String _
          Implements IEnumerator(Of String).Current
        Get
            If _sr Is Nothing OrElse _current Is Nothing
                Throw New InvalidOperationException()
            End If

            Return _current
        End Get
    End Property

    Private ReadOnly Property Current1 As Object _
          Implements IEnumerator.Current
        Get
           Return Me.Current
        End Get
    End Property

    ' Implement MoveNext and Reset, which are required by IEnumerator.
    Public Function MoveNext() As Boolean _
          Implements IEnumerator.MoveNext
        _current = _sr.ReadLine()
        if _current Is Nothing Then Return False

        Return True
    End Function

    Public Sub Reset() _
          Implements IEnumerator.Reset
        _sr.DiscardBufferedData()
        _sr.BaseStream.Seek(0, SeekOrigin.Begin)
        _current = Nothing
    End Sub

    ' Implement IDisposable, which is also implemented by IEnumerator(T).
    Private disposedValue As Boolean = False
    Public Sub Dispose() _
          Implements IDisposable.Dispose
        Dispose(True)
        GC.SuppressFinalize(Me)
    End Sub

    Protected Overridable Sub Dispose(disposing As Boolean)
        If Not Me.disposedValue Then
            If disposing Then
                ' Dispose of managed resources.
            End If

            _current = Nothing
            If _sr IsNot Nothing Then
               _sr.Close()
               _sr.Dispose()
            End If
        End If

        Me.disposedValue = True
    End Sub

    Protected Overrides Sub Finalize()
        Dispose(False)
    End Sub
End Class
' This example displays output similar to the following:
'       Found: 2
'       Memory Used With Iterator =     33kb
'       ---
'       Found: 2
'       Memory Used Without Iterator =  206kb

有关演示C#如何实现 IEnumerable<T> 接口的另一个示例，请参阅泛型示例。For another C# example that demonstrates how to implement the IEnumerable<T> interface, see the Generics Sample. 此示例使用 yield 关键字，而不是实现 IEnumerator<T>。This sample uses the yield keyword instead of implementing IEnumerator<T>.

注解

IEnumerable<T> 是 System.Collections.Generic 命名空间中的集合的基接口，如 List<T>、Dictionary<TKey,TValue>和 Stack<T> 以及其他泛型集合，如 ObservableCollection<T> 和 ConcurrentStack<T>。IEnumerable<T> is the base interface for collections in the System.Collections.Generic namespace such as List<T>, Dictionary<TKey,TValue>, and Stack<T> and other generic collections such as ObservableCollection<T> and ConcurrentStack<T>. 可以通过使用 foreach 语句来枚举实现 IEnumerable<T> 的集合。Collections that implement IEnumerable<T> can be enumerated by using the foreach statement.

有关此接口的非泛型版本，请参阅 System.Collections.IEnumerable。For the non-generic version of this interface, see System.Collections.IEnumerable.

IEnumerable<T> 包含实现此接口时必须实现的单个方法;GetEnumerator，它将返回一个 IEnumerator<T> 对象。IEnumerable<T> contains a single method that you must implement when implementing this interface; GetEnumerator, which returns an IEnumerator<T> object. 返回的 IEnumerator<T> 提供通过公开 Current 属性来循环访问集合的功能。The returned IEnumerator<T> provides the ability to iterate through the collection by exposing a Current property.

实施者说明

为了保持与迭代非泛型集合的方法兼容，IEnumerable<T> 实现 IEnumerable。To remain compatible with methods that iterate non-generic collections, IEnumerable<T> implements IEnumerable. 这允许将泛型集合传递到需要 IEnumerable 对象的方法。This allows a generic collection to be passed to a method that expects an IEnumerable object.

方法

GetEnumerator()

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

扩展方法

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 DataTable 为 DataRow 的输入 IEnumerable<T> 对象的情况下，返回包含 `T` 对象副本的 DataRow。Returns 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 DataRow 为 DataTable 的输入 IEnumerable<T> 对象的情况下，将 `T` 对象复制到指定的 DataRow。Copies 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 DataRow 为 DataTable 的输入 IEnumerable<T> 对象的情况下，将 `T` 对象复制到指定的 DataRow。Copies 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)	将 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 Int64。Returns 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 Int64。Returns 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>)	从 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>)	从 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>)	从 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)	将 IEnumerable 转换为 IQueryable。Converts 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.

IEnumerable<T> 接口

定义

类型参数

示例

注解

实施者说明

方法

扩展方法

适用于

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