Queryable.OrderBy Metodo

Definizione

Ordina in senso crescente gli elementi di una sequenza.Sorts the elements of a sequence in ascending order.

Overload

OrderBy<TSource,TKey>(IQueryable<TSource>, Expression<Func<TSource,TKey>>, IComparer<TKey>)

Ordina in ordine crescente gli elementi di una sequenza utilizzando un operatore di confronto specificato.Sorts the elements of a sequence in ascending order by using a specified comparer.

OrderBy<TSource,TKey>(IQueryable<TSource>, Expression<Func<TSource,TKey>>)

Ordina in senso crescente gli elementi di una sequenza secondo una chiave.Sorts the elements of a sequence in ascending order according to a key.

OrderBy<TSource,TKey>(IQueryable<TSource>, Expression<Func<TSource,TKey>>, IComparer<TKey>)

Ordina in ordine crescente gli elementi di una sequenza utilizzando un operatore di confronto specificato.Sorts the elements of a sequence in ascending order by using a specified comparer.

public:
generic <typename TSource, typename TKey>
[System::Runtime::CompilerServices::Extension]
 static System::Linq::IOrderedQueryable<TSource> ^ OrderBy(System::Linq::IQueryable<TSource> ^ source, System::Linq::Expressions::Expression<Func<TSource, TKey> ^> ^ keySelector, System::Collections::Generic::IComparer<TKey> ^ comparer);
public static System.Linq.IOrderedQueryable<TSource> OrderBy<TSource,TKey> (this System.Linq.IQueryable<TSource> source, System.Linq.Expressions.Expression<Func<TSource,TKey>> keySelector, System.Collections.Generic.IComparer<TKey> comparer);
public static System.Linq.IOrderedQueryable<TSource> OrderBy<TSource,TKey> (this System.Linq.IQueryable<TSource> source, System.Linq.Expressions.Expression<Func<TSource,TKey>> keySelector, System.Collections.Generic.IComparer<TKey>? comparer);
static member OrderBy : System.Linq.IQueryable<'Source> * System.Linq.Expressions.Expression<Func<'Source, 'Key>> * System.Collections.Generic.IComparer<'Key> -> System.Linq.IOrderedQueryable<'Source>
<Extension()>
Public Function OrderBy(Of TSource, TKey) (source As IQueryable(Of TSource), keySelector As Expression(Of Func(Of TSource, TKey)), comparer As IComparer(Of TKey)) As IOrderedQueryable(Of TSource)

Parametri di tipo

TSource

Tipo degli elementi di source.The type of the elements of source.

TKey

Tipo della chiave restituita dalla funzione rappresentata dall'oggetto keySelector.The type of the key returned by the function that is represented by keySelector.

Parametri

source
IQueryable<TSource>

Sequenza di valori da ordinare.A sequence of values to order.

keySelector
Expression<Func<TSource,TKey>>

Funzione per estrarre una chiave da un elemento.A function to extract a key from an element.

comparer
IComparer<TKey>

Oggetto IComparer<T> per confrontare le chiavi.An IComparer<T> to compare keys.

Restituisce

IOrderedQueryable<TSource>

Oggetto IOrderedQueryable<T> i cui elementi vengono ordinati secondo una chiave.An IOrderedQueryable<T> whose elements are sorted according to a key.

Eccezioni

Il parametro source, il parametro keySelector o il parametro comparer è null.source or keySelector or comparer is null.

Commenti

Questo metodo ha almeno un parametro di tipo Expression<TDelegate> il cui argomento di tipo è uno dei Func<T,TResult> tipi.This method has at least one parameter of type Expression<TDelegate> whose type argument is one of the Func<T,TResult> types. Per questi parametri, è possibile passare un'espressione lambda che verrà compilata in un oggetto Expression<TDelegate> .For these parameters, you can pass in a lambda expression and it will be compiled to an Expression<TDelegate>.

Il OrderBy<TSource,TKey>(IQueryable<TSource>, Expression<Func<TSource,TKey>>, IComparer<TKey>) metodo genera un oggetto MethodCallExpression che rappresenta la chiamata a OrderBy<TSource,TKey>(IQueryable<TSource>, Expression<Func<TSource,TKey>>, IComparer<TKey>) se stesso come metodo generico costruito.The OrderBy<TSource,TKey>(IQueryable<TSource>, Expression<Func<TSource,TKey>>, IComparer<TKey>) method generates a MethodCallExpression that represents calling OrderBy<TSource,TKey>(IQueryable<TSource>, Expression<Func<TSource,TKey>>, IComparer<TKey>) itself as a constructed generic method. Passa quindi al MethodCallExpression CreateQuery<TElement>(Expression) metodo dell'oggetto IQueryProvider rappresentato dalla Provider proprietà del source parametro.It then passes the MethodCallExpression to the CreateQuery<TElement>(Expression) method of the IQueryProvider represented by the Provider property of the source parameter. Il risultato della chiamata CreateQuery<TElement>(Expression) a viene eseguito il cast al tipo IOrderedQueryable<T> e restituito.The result of calling CreateQuery<TElement>(Expression) is cast to type IOrderedQueryable<T> and returned.

Il comportamento della query che si verifica in seguito all'esecuzione di un albero delle espressioni che rappresenta la chiamata OrderBy<TSource,TKey>(IQueryable<TSource>, Expression<Func<TSource,TKey>>, IComparer<TKey>) dipende dall'implementazione del tipo di source parametro.The query behavior that occurs as a result of executing an expression tree that represents calling OrderBy<TSource,TKey>(IQueryable<TSource>, Expression<Func<TSource,TKey>>, IComparer<TKey>) depends on the implementation of the type of the source parameter. Il comportamento previsto è che ordina gli elementi di source in base alla chiave ottenuta richiamando keySelector su ogni elemento di source .The expected behavior is that it sorts the elements of source based on the key obtained by invoking keySelector on each element of source. Il comparer parametro viene utilizzato per confrontare le chiavi.The comparer parameter is used to compare keys.

OrderBy<TSource,TKey>(IQueryable<TSource>, Expression<Func<TSource,TKey>>)

Ordina in senso crescente gli elementi di una sequenza secondo una chiave.Sorts the elements of a sequence in ascending order according to a key.

public:
generic <typename TSource, typename TKey>
[System::Runtime::CompilerServices::Extension]
 static System::Linq::IOrderedQueryable<TSource> ^ OrderBy(System::Linq::IQueryable<TSource> ^ source, System::Linq::Expressions::Expression<Func<TSource, TKey> ^> ^ keySelector);
public static System.Linq.IOrderedQueryable<TSource> OrderBy<TSource,TKey> (this System.Linq.IQueryable<TSource> source, System.Linq.Expressions.Expression<Func<TSource,TKey>> keySelector);
static member OrderBy : System.Linq.IQueryable<'Source> * System.Linq.Expressions.Expression<Func<'Source, 'Key>> -> System.Linq.IOrderedQueryable<'Source>
<Extension()>
Public Function OrderBy(Of TSource, TKey) (source As IQueryable(Of TSource), keySelector As Expression(Of Func(Of TSource, TKey))) As IOrderedQueryable(Of TSource)

Parametri di tipo

TSource

Tipo degli elementi di source.The type of the elements of source.

TKey

Tipo della chiave restituita dalla funzione rappresentata dall'oggetto keySelector.The type of the key returned by the function that is represented by keySelector.

Parametri

source
IQueryable<TSource>

Sequenza di valori da ordinare.A sequence of values to order.

keySelector
Expression<Func<TSource,TKey>>

Funzione per estrarre una chiave da un elemento.A function to extract a key from an element.

Restituisce

IOrderedQueryable<TSource>

Oggetto IOrderedQueryable<T> i cui elementi vengono ordinati secondo una chiave.An IOrderedQueryable<T> whose elements are sorted according to a key.

Eccezioni

source o keySelector è null.source or keySelector is null.

Esempio

Nell'esempio di codice riportato di seguito viene illustrato come utilizzare OrderBy<TSource,TKey>(IQueryable<TSource>, Expression<Func<TSource,TKey>>) per ordinare gli elementi di una sequenza.The following code example demonstrates how to use OrderBy<TSource,TKey>(IQueryable<TSource>, Expression<Func<TSource,TKey>>) to sort the elements of a sequence.

class Pet
{
    public string Name { get; set; }
    public int Age { get; set; }
}

public static void OrderByEx1()
{
    Pet[] pets = { new Pet { Name="Barley", Age=8 },
                   new Pet { Name="Boots", Age=4 },
                   new Pet { Name="Whiskers", Age=1 } };

    // Sort the Pet objects in the array by Pet.Age.
    IEnumerable<Pet> query =
        pets.AsQueryable().OrderBy(pet => pet.Age);

    foreach (Pet pet in query)
        Console.WriteLine("{0} - {1}", pet.Name, pet.Age);
}

/*
    This code produces the following output:

    Whiskers - 1
    Boots - 4
    Barley - 8
*/

Structure Pet
    Public Name As String
    Public Age As Integer
End Structure

Shared Sub OrderByEx1()
    Dim pets() As Pet = {New Pet With {.Name = "Barley", .Age = 8}, _
                         New Pet With {.Name = "Boots", .Age = 4}, _
                         New Pet With {.Name = "Whiskers", .Age = 1}}

    ' Sort the Pet objects in the array by Pet.Age.
    Dim query As IEnumerable(Of Pet) = _
                pets.AsQueryable().OrderBy(Function(pet) pet.Age)

    Dim output As New System.Text.StringBuilder
    For Each pet As Pet In query
        output.AppendLine(String.Format("{0} - {1}", pet.Name, pet.Age))
    Next

    ' Display the output.
    MsgBox(output.ToString())
End Sub

' This code produces the following output:

' Whiskers - 1
' Boots - 4
' Barley - 8

Commenti

Questo metodo ha almeno un parametro di tipo Expression<TDelegate> il cui argomento di tipo è uno dei Func<T,TResult> tipi.This method has at least one parameter of type Expression<TDelegate> whose type argument is one of the Func<T,TResult> types. Per questi parametri, è possibile passare un'espressione lambda che verrà compilata in un oggetto Expression<TDelegate> .For these parameters, you can pass in a lambda expression and it will be compiled to an Expression<TDelegate>.

Il OrderBy<TSource,TKey>(IQueryable<TSource>, Expression<Func<TSource,TKey>>) metodo genera un oggetto MethodCallExpression che rappresenta la chiamata a OrderBy<TSource,TKey>(IQueryable<TSource>, Expression<Func<TSource,TKey>>) se stesso come metodo generico costruito.The OrderBy<TSource,TKey>(IQueryable<TSource>, Expression<Func<TSource,TKey>>) method generates a MethodCallExpression that represents calling OrderBy<TSource,TKey>(IQueryable<TSource>, Expression<Func<TSource,TKey>>) itself as a constructed generic method. Passa quindi al MethodCallExpression CreateQuery<TElement>(Expression) metodo dell'oggetto IQueryProvider rappresentato dalla Provider proprietà del source parametro.It then passes the MethodCallExpression to the CreateQuery<TElement>(Expression) method of the IQueryProvider represented by the Provider property of the source parameter. Il risultato della chiamata CreateQuery<TElement>(Expression) a viene eseguito il cast al tipo IOrderedQueryable<T> e restituito.The result of calling CreateQuery<TElement>(Expression) is cast to type IOrderedQueryable<T> and returned.

Il comportamento della query che si verifica in seguito all'esecuzione di un albero delle espressioni che rappresenta la chiamata OrderBy<TSource,TKey>(IQueryable<TSource>, Expression<Func<TSource,TKey>>) dipende dall'implementazione del tipo di source parametro.The query behavior that occurs as a result of executing an expression tree that represents calling OrderBy<TSource,TKey>(IQueryable<TSource>, Expression<Func<TSource,TKey>>) depends on the implementation of the type of the source parameter. Il comportamento previsto è che ordina gli elementi di source in base alla chiave ottenuta richiamando keySelector su ogni elemento di source .The expected behavior is that it sorts the elements of source based on the key obtained by invoking keySelector on each element of source.

Si applica a