Queryable.All(IQueryable<TSource>, Expression<Func<TSource,Boolean>>) Queryable.All(IQueryable<TSource>, Expression<Func<TSource,Boolean>>) Queryable.All(IQueryable<TSource>, Expression<Func<TSource,Boolean>>) Queryable.All(IQueryable<TSource>, Expression<Func<TSource,Boolean>>) Method

定義

シーケンスのすべての要素が条件を満たしているかどうかを判断します。Determines whether all the elements of a sequence satisfy a condition.

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

型パラメーター

TSource

source の要素の型。The type of the elements of source.

パラメーター

source
IQueryable<TSource>

条件を満たしているかどうかをテストする要素を含むシーケンス。A sequence whose elements to test for a condition.

predicate
Expression<Func<TSource,Boolean>>

各要素が条件を満たしているかどうかをテストする関数。A function to test each element for a condition.

戻り値

指定された述語でソース シーケンスのすべての要素がテストに合格する場合は true。それ以外の場合は falsetrue if every element of the source sequence passes the test in the specified predicate, or if the sequence is empty; otherwise, false.

例外

source または predicatenull です。source or predicate is null.

次のコード例では、をAll<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>)使用して、シーケンス内のすべての要素が条件を満たしているかどうかを確認する方法を示します。The following code example demonstrates how to use All<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>) to determine whether all the elements in a sequence satisfy a condition.

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

public static void AllEx1()
{
    // Create an array of Pets.
    Pet[] pets = { new Pet { Name="Barley", Age=10 },
                   new Pet { Name="Boots", Age=4 },
                   new Pet { Name="Whiskers", Age=6 } };

    // Determine whether all pet names in the array start with 'B'.
    bool allStartWithB =
        pets.AsQueryable().All(pet => pet.Name.StartsWith("B"));

    Console.WriteLine(
        "{0} pet names start with 'B'.",
        allStartWithB ? "All" : "Not all");
}

// This code produces the following output:
//
//  Not all pet names start with 'B'. 

Sub AllEx()
    ' Create an array of Pets.
    Dim pets() As Pet = _
        {New Pet With {.Name = "Barley", .Age = 10}, _
         New Pet With {.Name = "Boots", .Age = 4}, _
         New Pet With {.Name = "Whiskers", .Age = 6}}

    ' Determine whether all pet names in the array start with 'B'.
    Dim allStartWithB As Boolean = _
        pets.AsQueryable().All(Function(ByVal pet) pet.Name.StartsWith("B"))

    MsgBox(String.Format( _
        "{0} pet names start with 'B'.", _
        IIf(allStartWithB, "All", "Not all")))
End Sub

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

' This code produces the following output:
'
'  Not all pet names start with 'B'. 

All<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>)メソッドが返すブール値は、通常、 where句の述語 (Where Where Visual Basic 内の句) またはメソッドの直接呼び出しで使用されます。The Boolean value that the All<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>) method returns is typically used in the predicate of a where clause (Where clause in Visual Basic) or a direct call to the Where method. このAllメソッドの使用例を次に示します。The following example demonstrates this use of the All method.

class Pet
{
    public string Name { get; set; }
    public int Age { get; set; }
}
class Person
{
    public string LastName { get; set; }
    public Pet[] Pets { get; set; }
}

public static void AllEx2()
{
    List<Person> people = new List<Person>
        { new Person { LastName = "Haas",
                       Pets = new Pet[] { new Pet { Name="Barley", Age=10 },
                                          new Pet { Name="Boots", Age=14 },
                                          new Pet { Name="Whiskers", Age=6 }}},
          new Person { LastName = "Fakhouri",
                       Pets = new Pet[] { new Pet { Name = "Snowball", Age = 1}}},
          new Person { LastName = "Antebi",
                       Pets = new Pet[] { new Pet { Name = "Belle", Age = 8} }},
          new Person { LastName = "Philips",
                       Pets = new Pet[] { new Pet { Name = "Sweetie", Age = 2},
                                          new Pet { Name = "Rover", Age = 13}} }
        };

    // Determine which people have pets that are all older than 5.
    IEnumerable<string> names = from person in people
                                where person.Pets.AsQueryable().All(pet => pet.Age > 5)
                                select person.LastName;

    foreach (string name in names)
        Console.WriteLine(name);

    /* This code produces the following output:
     * 
     * Haas
     * Antebi
     */
}
Structure Pet
    Public Name As String
    Public Age As Integer
End Structure

Structure Person
    Public LastName As String
    Public Pets() As Pet
End Structure

Sub AllEx2()
    Dim people As New List(Of Person)(New Person() _
        {New Person With {.LastName = "Haas", _
                          .Pets = New Pet() {New Pet With {.Name = "Barley", .Age = 10}, _
                                             New Pet With {.Name = "Boots", .Age = 14}, _
                                             New Pet With {.Name = "Whiskers", .Age = 6}}}, _
          New Person With {.LastName = "Fakhouri", _
                           .Pets = New Pet() {New Pet With {.Name = "Snowball", .Age = 1}}}, _
          New Person With {.LastName = "Antebi", _
                           .Pets = New Pet() {New Pet With {.Name = "Belle", .Age = 8}}}, _
          New Person With {.LastName = "Philips", _
                           .Pets = New Pet() {New Pet With {.Name = "Sweetie", .Age = 2}, _
                                              New Pet With {.Name = "Rover", .Age = 13}}}})

    ' Determine which people have pets that are all older than 5.
    Dim names = From person In people _
                Where person.Pets.AsQueryable().All(Function(pet) pet.Age > 5) _
                Select person.LastName

    For Each name As String In names
        Console.WriteLine(name)
    Next

    ' This code produces the following output:
    '
    ' Haas
    ' Antebi

End Sub

注釈

このメソッドには、型引数が型Expression<TDelegate>の1つ以上の型のFunc<T,TResult>パラメーターが少なくとも1つ含まれています。This method has at least one parameter of type Expression<TDelegate> whose type argument is one of the Func<T,TResult> types. これらのパラメーターの場合は、ラムダ式を渡すことができ、にExpression<TDelegate>コンパイルされます。For these parameters, you can pass in a lambda expression and it will be compiled to an Expression<TDelegate>.

メソッドAll<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>)は、構築MethodCallExpressionされたAll<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>)ジェネリックメソッドとして呼び出し元を表すを生成します。The All<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>) method generates a MethodCallExpression that represents calling All<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>) itself as a constructed generic method. MethodCallExpressionに、 IQueryProvider Execute<TResult>(Expression) パラメーターsourceProviderプロパティによって表されるのメソッドにを渡します。It then passes the MethodCallExpression to the Execute<TResult>(Expression) method of the IQueryProvider represented by the Provider property of the source parameter.

呼び出しAll<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>)を表す式ツリーを実行した結果として発生するクエリ動作は、 sourceパラメーターの型の実装によって異なります。The query behavior that occurs as a result of executing an expression tree that represents calling All<TSource>(IQueryable<TSource>, Expression<Func<TSource,Boolean>>) depends on the implementation of the source parameter's type. 期待される動作は、のsourceすべての要素がのpredicate条件を満たすかどうかを判断することです。The expected behavior is that it determines if all the elements in source satisfy the condition in predicate.

適用対象