IOrderedEnumerable<TElement>.CreateOrderedEnumerable<TKey> 方法

定義

命名空間:

System.Linq

組件:

System.Linq.dll

依據索引鍵，在 IOrderedEnumerable<TElement> 的項目上執行後續的排序。

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)

類型參數

TKey

keySelector 所產生的索引鍵型別。

參數

keySelector

Func<TElement,TKey>

Func<T,TResult>，用來擷取每個項目的索引鍵。

comparer

IComparer<TKey>

IComparer<T>，用來比較索引鍵，以便在傳回的序列中放置。

descending

Boolean

true 表示依遞減順序排序項目，false 表示依遞增順序排序項目。

傳回

IOrderedEnumerable<TElement>

依據索引鍵排序其項目的 IOrderedEnumerable<TElement>。

範例

下列程式代碼範例示範如何使用 CreateOrderedEnumerable 在上 IOrderedEnumerable<TElement>執行次要排序。

// 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

備註

這個方法所提供的功能類似於 或 所提供的ThenBy功能，視 是 descendingtrue 或 ThenByDescendingfalse而定。 兩者都會執行已排序之型 IOrderedEnumerable<TElement>別 的次級順序。