Queryable.ThenBy Queryable.ThenBy Queryable.ThenBy Queryable.ThenBy Method

Definizione

Esegue un ordinamento successivo degli elementi in una sequenza in ordine crescente.Performs a subsequent ordering of the elements in a sequence in ascending order.

Overload

ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>, IComparer<TKey>) ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>, IComparer<TKey>) ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>, IComparer<TKey>) ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>, IComparer<TKey>)

Esegue un ordinamento successivo degli elementi in una sequenza in ordine crescente usando un operatore di confronto specificato.Performs a subsequent ordering of the elements in a sequence in ascending order by using a specified comparer.

ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>) ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>) ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>) ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>)

Esegue un ordinamento successivo degli elementi in una sequenza crescente in base a una chiave.Performs a subsequent ordering of the elements in a sequence in ascending order according to a key.

ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>, IComparer<TKey>) ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>, IComparer<TKey>) ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>, IComparer<TKey>) ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>, IComparer<TKey>)

Esegue un ordinamento successivo degli elementi in una sequenza in ordine crescente usando un operatore di confronto specificato.Performs a subsequent ordering of the elements in 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> ^ ThenBy(System::Linq::IOrderedQueryable<TSource> ^ source, System::Linq::Expressions::Expression<Func<TSource, TKey> ^> ^ keySelector, System::Collections::Generic::IComparer<TKey> ^ comparer);
public static System.Linq.IOrderedQueryable<TSource> ThenBy<TSource,TKey> (this System.Linq.IOrderedQueryable<TSource> source, System.Linq.Expressions.Expression<Func<TSource,TKey>> keySelector, System.Collections.Generic.IComparer<TKey> comparer);
static member ThenBy : System.Linq.IOrderedQueryable<'Source> * System.Linq.Expressions.Expression<Func<'Source, 'Key>> * System.Collections.Generic.IComparer<'Key> -> System.Linq.IOrderedQueryable<'Source>
<Extension()>
Public Function ThenBy(Of TSource, TKey) (source As IOrderedQueryable(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

Il tipo della chiave restituita dalla funzione rappresentata da keySelector.The type of the key returned by the function represented by keySelector.

Parametri

source
IOrderedQueryable<TSource>

Oggetto IOrderedQueryable<T> che contiene gli elementi da ordinare.An IOrderedQueryable<T> that contains elements to sort.

keySelector
Expression<Func<TSource,TKey>>

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

comparer
IComparer<TKey>

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

Restituisce

Un IOrderedQueryable<T> cui elementi vengono ordinati in base a 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 tipo è uno del 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 in un'espressione lambda e verrà compilata per un Expression<TDelegate>.For these parameters, you can pass in a lambda expression and it will be compiled to an Expression<TDelegate>.

Il ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>, IComparer<TKey>) metodo genera un MethodCallExpression che rappresenta una chiamata ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>, IComparer<TKey>) stesso come un metodo generico costruito.The ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>, IComparer<TKey>) method generates a MethodCallExpression that represents calling ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>, IComparer<TKey>) itself as a constructed generic method. Passa quindi il MethodCallExpression per il CreateQuery<TElement>(Expression) metodo del IQueryProvider rappresentato dal 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 al metodo CreateQuery<TElement>(Expression) viene eseguito il cast al tipo IOrderedQueryable<T> e restituiti.The result of calling CreateQuery<TElement>(Expression) is cast to type IOrderedQueryable<T> and returned.

Il comportamento delle query che si verifica in seguito all'esecuzione di un albero delle espressioni che rappresenta una chiamata ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>, IComparer<TKey>) dipende dall'implementazione del tipo del source parametro.The query behavior that occurs as a result of executing an expression tree that represents calling ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>, IComparer<TKey>) depends on the implementation of the type of the source parameter. Il comportamento previsto è che viene eseguito un ordinamento secondario degli elementi della source basato sulla chiave ottenuta chiamando keySelector su ogni elemento di source.The expected behavior is that it performs a secondary sort of the elements of source based on the key obtained by invoking keySelector on each element of source. Tutte definite in precedenza vengono mantenuti gli ordinamenti.All previously established sort orders are preserved. Il comparer parametro viene usato per confrontare i valori di chiave.The comparer parameter is used to compare key values.

ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>) ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>) ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>) ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>)

Esegue un ordinamento successivo degli elementi in una sequenza crescente in base a una chiave.Performs a subsequent ordering of the elements in a sequence in ascending order according to a key.

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

Il tipo della chiave restituita dalla funzione rappresentata da keySelector.The type of the key returned by the function represented by keySelector.

Parametri

source
IOrderedQueryable<TSource>

Oggetto IOrderedQueryable<T> che contiene gli elementi da ordinare.An IOrderedQueryable<T> that contains elements to sort.

keySelector
Expression<Func<TSource,TKey>>

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

Restituisce

Un IOrderedQueryable<T> cui elementi vengono ordinati in base a una chiave.An IOrderedQueryable<T> whose elements are sorted according to a key.

Eccezioni

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

Esempi

Esempio di codice seguente viene illustrato come utilizzare ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>) per eseguire un ordinamento secondario degli elementi in una sequenza.The following code example demonstrates how to use ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>) to perform a secondary ordering of the elements in a sequence.

string[] fruits = { "grape", "passionfruit", "banana", "apple", 
                      "orange", "raspberry", "mango", "blueberry" };

// Sort the strings first by their length and then 
// alphabetically by passing the identity selector function.
IEnumerable<string> query =
    fruits.AsQueryable()
    .OrderBy(fruit => fruit.Length).ThenBy(fruit => fruit);

foreach (string fruit in query)
    Console.WriteLine(fruit);

/*
    This code produces the following output:

    apple
    grape
    mango
    banana
    orange
    blueberry
    raspberry
    passionfruit
*/

Dim fruits() As String = _
    {"grape", "passionfruit", "banana", "mango", _
     "orange", "raspberry", "apple", "blueberry"}

' Sort the strings first by their length and then 
' alphabetically by passing the identity selector function.
Dim query = fruits.AsQueryable() _
    .OrderBy(Function(fruit) fruit.Length).ThenBy(Function(fruit) fruit)

' Display the results.
Dim output As New System.Text.StringBuilder
For Each fruit As String In query
    output.AppendLine(fruit)
Next
MsgBox(output.ToString())

'This code produces the following output:

'apple
'grape
'mango
'banana
'orange
'blueberry
'raspberry
'passionfruit

Commenti

Questo metodo ha almeno un parametro di tipo Expression<TDelegate> il cui argomento tipo è uno del 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 in un'espressione lambda e verrà compilata per un Expression<TDelegate>.For these parameters, you can pass in a lambda expression and it will be compiled to an Expression<TDelegate>.

Il ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>) metodo genera un MethodCallExpression che rappresenta una chiamata ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>) stesso come un metodo generico costruito.The ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>) method generates a MethodCallExpression that represents calling ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>) itself as a constructed generic method. Passa quindi il MethodCallExpression per il CreateQuery<TElement>(Expression) metodo del IQueryProvider rappresentato dal 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 al metodo CreateQuery<TElement>(Expression) viene eseguito il cast al tipo IOrderedQueryable<T> e restituiti.The result of calling CreateQuery<TElement>(Expression) is cast to type IOrderedQueryable<T> and returned.

Il comportamento delle query che si verifica in seguito all'esecuzione di un albero delle espressioni che rappresenta una chiamata ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>) dipende dall'implementazione del tipo del source parametro.The query behavior that occurs as a result of executing an expression tree that represents calling ThenBy<TSource,TKey>(IOrderedQueryable<TSource>, Expression<Func<TSource,TKey>>) depends on the implementation of the type of the source parameter. Il comportamento previsto è che viene eseguito un ordinamento secondario degli elementi della source basato sulla chiave ottenuta chiamando keySelector su ogni elemento di source.The expected behavior is that it performs a secondary sort of the elements of source based on the key obtained by invoking keySelector on each element of source. Tutte definite in precedenza vengono mantenuti gli ordinamenti.All previously established sort orders are preserved.

Si applica a