Queryable.Max Queryable.Max Queryable.Max Queryable.Max Method

Definizione

Overload

Max<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) Max<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) Max<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) Max<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>)

Richiama una funzione di proiezione su ogni elemento di un oggetto generico IQueryable<T> e restituisce il valore massimo risultante.Invokes a projection function on each element of a generic IQueryable<T> and returns the maximum resulting value.

Max<TSource>(IQueryable<TSource>) Max<TSource>(IQueryable<TSource>) Max<TSource>(IQueryable<TSource>) Max<TSource>(IQueryable<TSource>)

Restituisce il valore massimo in un oggetto generico IQueryable<T>.Returns the maximum value in a generic IQueryable<T>.

Max<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) Max<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) Max<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) Max<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>)

Richiama una funzione di proiezione su ogni elemento di un oggetto generico IQueryable<T> e restituisce il valore massimo risultante.Invokes a projection function on each element of a generic IQueryable<T> and returns the maximum resulting value.

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

Parametri di tipo

TSource

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

TResult

Il tipo del valore restituito dalla funzione rappresentata da selector.The type of the value returned by the function represented by selector.

Parametri

source
IQueryable<TSource>

Una sequenza di valori per determinare il numero massimo di.A sequence of values to determine the maximum of.

selector
Expression<Func<TSource,TResult>>

Una funzione di proiezione da applicare a ogni elemento.A projection function to apply to each element.

Restituisce

TResult TResult TResult TResult

Valore massimo della sequenza.The maximum value in the sequence.

Eccezioni

source o selector è null.source or selector is null.

Esempi

Esempio di codice seguente viene illustrato come utilizzare Max<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) per determinare il valore massimo in una sequenza di valori proiettati.The following code example demonstrates how to use Max<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) to determine the maximum value in a sequence of projected values.

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

public static void MaxEx2()
{
    Pet[] pets = { new Pet { Name="Barley", Age=8 },
                   new Pet { Name="Boots", Age=4 },
                   new Pet { Name="Whiskers", Age=1 } };

    // Add Pet.Age to the length of Pet.Name
    // to determine the "maximum" Pet object in the array.
    int max =
        pets.AsQueryable().Max(pet => pet.Age + pet.Name.Length);

    Console.WriteLine(
        "The maximum pet age plus name length is {0}.",
        max);
}

/*
    This code produces the following output:

    The maximum pet age plus name length is 14.
*/

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

Shared Sub MaxEx2()
    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}}

    ' Add Pet.Age to the length of Pet.Name
    ' to determine the "maximum" Pet object in the array.
    Dim max As Integer = _
        pets.AsQueryable().Max(Function(pet) pet.Age + pet.Name.Length)

    MsgBox(String.Format("The maximum pet age plus name length is {0}.", max))

    'This code produces the following output:

    'The maximum pet age plus name length is 14.

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 Max<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) metodo genera un MethodCallExpression che rappresenta una chiamata Max<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) stesso come un metodo generico costruito.The Max<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) method generates a MethodCallExpression that represents calling Max<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) itself as a constructed generic method. Passa quindi il MethodCallExpression per il Execute<TResult>(Expression) metodo del IQueryProvider rappresentato dal Provider proprietà del source parametro.It then passes the MethodCallExpression to the Execute<TResult>(Expression) method of the IQueryProvider represented by the Provider property of the source parameter.

Il comportamento delle query che si verifica in seguito all'esecuzione di un albero delle espressioni che rappresenta una chiamata Max<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) dipende dall'implementazione del tipo del source parametro.The query behavior that occurs as a result of executing an expression tree that represents calling Max<TSource,TResult>(IQueryable<TSource>, Expression<Func<TSource,TResult>>) depends on the implementation of the type of the source parameter. Il comportamento previsto è che richiami selector su ogni elemento in source e restituisce il valore massimo.The expected behavior is that it invokes selector on each element in source and returns the maximum value.

Max<TSource>(IQueryable<TSource>) Max<TSource>(IQueryable<TSource>) Max<TSource>(IQueryable<TSource>) Max<TSource>(IQueryable<TSource>)

Restituisce il valore massimo in un oggetto generico IQueryable<T>.Returns the maximum value in a generic IQueryable<T>.

public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
 static TSource Max(System::Linq::IQueryable<TSource> ^ source);
public static TSource Max<TSource> (this System.Linq.IQueryable<TSource> source);
static member Max : System.Linq.IQueryable<'Source> -> 'Source
<Extension()>
Public Function Max(Of TSource) (source As IQueryable(Of TSource)) As TSource

Parametri di tipo

TSource

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

Parametri

source
IQueryable<TSource>

Una sequenza di valori per determinare il numero massimo di.A sequence of values to determine the maximum of.

Restituisce

TSource TSource TSource TSource

Valore massimo della sequenza.The maximum value in the sequence.

Eccezioni

Esempi

Esempio di codice seguente viene illustrato come utilizzare Max<TSource>(IQueryable<TSource>) per determinare il valore massimo in una sequenza.The following code example demonstrates how to use Max<TSource>(IQueryable<TSource>) to determine the maximum value in a sequence.

List<long> longs = new List<long> { 4294967296L, 466855135L, 81125L };

long max = longs.AsQueryable().Max();

Console.WriteLine("The largest number is {0}.", max);

/*
    This code produces the following output:

    The largest number is 4294967296.
*/

Dim longs As New List(Of Long)(New Long() {4294967296L, 466855135L, 81125L})

Dim max As Long = longs.AsQueryable().Max()

MsgBox(String.Format("The largest number is {0}.", max))

'This code produces the following output:

'The largest number is 4294967296.

Commenti

Il Max<TSource>(IQueryable<TSource>) metodo genera un MethodCallExpression che rappresenta una chiamata Max<TSource>(IQueryable<TSource>) stesso come un metodo generico costruito.The Max<TSource>(IQueryable<TSource>) method generates a MethodCallExpression that represents calling Max<TSource>(IQueryable<TSource>) itself as a constructed generic method. Passa quindi il MethodCallExpression per il Execute<TResult>(Expression) metodo del IQueryProvider rappresentato dal Provider proprietà del source parametro.It then passes the MethodCallExpression to the Execute<TResult>(Expression) method of the IQueryProvider represented by the Provider property of the source parameter.

Il comportamento delle query che si verifica in seguito all'esecuzione di un albero delle espressioni che rappresenta una chiamata Max<TSource>(IQueryable<TSource>) dipende dall'implementazione del tipo del source parametro.The query behavior that occurs as a result of executing an expression tree that represents calling Max<TSource>(IQueryable<TSource>) depends on the implementation of the type of the source parameter. Il comportamento previsto è che restituisce il valore massimo in source.The expected behavior is that it returns the maximum value in source.

Si applica a