IOrderedEnumerable<TElement>.CreateOrderedEnumerable<TKey> 方法

定义

命名空间:

System.Linq

程序集:

System.Linq.dll

根据某个键对 IOrderedEnumerable<TElement> 的元素执行后续排序。

public:
generic <typename TKey>
 System::Linq::IOrderedEnumerable<TElement> ^ CreateOrderedEnumerable(Func<TElement, TKey> ^ keySelector, System::Collections::Generic::IComparer<TKey> ^ comparer, bool descending);

public System.Linq.IOrderedEnumerable<out TElement> CreateOrderedEnumerable<TKey> (Func<out TElement,TKey> keySelector, System.Collections.Generic.IComparer<TKey>? comparer, bool descending);

abstract member CreateOrderedEnumerable : Func<'Element, 'Key> * System.Collections.Generic.IComparer<'Key> * bool -> System.Linq.IOrderedEnumerable<'Element>

Public Function CreateOrderedEnumerable(Of TKey) (keySelector As Func(Of Out TElement, TKey), comparer As IComparer(Of TKey), descending As Boolean) As IOrderedEnumerable(Of Out TElement)

类型参数

TKey

keySelector 生成的键的类型。

参数

keySelector

Func<TElement,TKey>

用于提取每个元素的键的 Func<T,TResult>。

comparer

IComparer<TKey>

用于比较键在返回序列中的位置的 IComparer<T>。

descending

Boolean

如果为 true，则对元素进行降序排序；如果为 false，则对元素进行升序排序。

返回

IOrderedEnumerable<TElement>

一个 IOrderedEnumerable<TElement>，将根据键对其元素排序。

示例

下面的代码示例演示如何使用 CreateOrderedEnumerable 对 执行辅助排序 IOrderedEnumerable<TElement>。

// Create an array of strings to sort.
string[] fruits = { "apricot", "orange", "banana", "mango", "apple", "grape", "strawberry" };
// First sort the strings by their length.
IOrderedEnumerable<string> sortedFruits2 =
    fruits.OrderBy(fruit => fruit.Length);
// Secondarily sort the strings alphabetically, using the default comparer.
IOrderedEnumerable<string> sortedFruits3 =
    sortedFruits2.CreateOrderedEnumerable<string>(
        fruit => fruit,
        Comparer<string>.Default, false);

// Output the resulting sequence of strings.
foreach (string fruit in sortedFruits3)
    Console.WriteLine(fruit);

// This code produces the following output:
//
// apple
// grape
// mango
// banana
// orange
// apricot
// strawberry

' Create an array of strings to sort.
Dim fruits() As String = {"apricot", "orange", "banana", "mango", "apple", "grape", "strawberry"}
' First sort the strings by their length.
Dim sortedFruits2 As IOrderedEnumerable(Of String) = _
    fruits.OrderBy(Function(ByVal fruit) fruit.Length)
' Secondarily sort the strings alphabetically, using the default comparer.
Dim sortedFruits3 As IOrderedEnumerable(Of String) = _
    sortedFruits2.CreateOrderedEnumerable(Of String)( _
        Function(ByVal fruit) fruit, _
        System.Collections.Generic.Comparer(Of String).Default, _
        False)

Dim output As New System.Text.StringBuilder
' Output the resulting sequence of strings.
For Each fruit As String In sortedFruits3
    output.AppendLine(fruit)
Next

' Display the results.
MsgBox(output.ToString())

' This code produces the following output:
'
' apple
' grape
' mango
' banana
' orange
' apricot
' strawberry

注解

此方法提供的功能类似于 或 提供ThenBy的功能，具体取决于 是 descendingtrue 还是 false。ThenByDescending 它们都对类型 IOrderedEnumerable<TElement>已排序的序列执行从属排序。