Queryable.Concat<TSource> Metod

public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
 static System::Linq::IQueryable<TSource> ^ Concat(System::Linq::IQueryable<TSource> ^ source1, System::Collections::Generic::IEnumerable<TSource> ^ source2);

public static System.Linq.IQueryable<TSource> Concat<TSource>(this System.Linq.IQueryable<TSource> source1, System.Collections.Generic.IEnumerable<TSource> source2);

[System.Diagnostics.CodeAnalysis.RequiresDynamicCode("Enumerating collections as IQueryable can require creating new generic types or methods, which requires creating code at runtime. This may not work when AOT compiling.")]
public static System.Linq.IQueryable<TSource> Concat<TSource>(this System.Linq.IQueryable<TSource> source1, System.Collections.Generic.IEnumerable<TSource> source2);

static member Concat : System.Linq.IQueryable<'Source> * seq<'Source> -> System.Linq.IQueryable<'Source>

[<System.Diagnostics.CodeAnalysis.RequiresDynamicCode("Enumerating collections as IQueryable can require creating new generic types or methods, which requires creating code at runtime. This may not work when AOT compiling.")>]
static member Concat : System.Linq.IQueryable<'Source> * seq<'Source> -> System.Linq.IQueryable<'Source>

<Extension()>
Public Function Concat(Of TSource) (source1 As IQueryable(Of TSource), source2 As IEnumerable(Of TSource)) As IQueryable(Of TSource)

Typparametrar

Parametrar

Returer

En IQueryable<T> som innehåller de sammanfogade elementen i de två indatasekvenserna.

Attribut

RequiresDynamicCodeAttribute

Undantag

Exempel

Följande kodexempel visar hur du använder Concat<TSource>(IQueryable<TSource>, IEnumerable<TSource>) för att sammanfoga två sekvenser.

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

// This method creates and returns an array of Pet objects.
static Pet[] GetCats()
{
    Pet[] cats = { new Pet { Name="Barley", Age=8 },
                   new Pet { Name="Boots", Age=4 },
                   new Pet { Name="Whiskers", Age=1 } };
    return cats;
}

// This method creates and returns an array of Pet objects.
static Pet[] GetDogs()
{
    Pet[] dogs = { new Pet { Name="Bounder", Age=3 },
                   new Pet { Name="Snoopy", Age=14 },
                   new Pet { Name="Fido", Age=9 } };
    return dogs;
}

public static void ConcatEx1()
{
    Pet[] cats = GetCats();
    Pet[] dogs = GetDogs();

    // Concatenate a collection of cat names to a
    // collection of dog names by using Concat().
    IEnumerable<string> query =
        cats.AsQueryable()
        .Select(cat => cat.Name)
        .Concat(dogs.Select(dog => dog.Name));

    foreach (string name in query)
        Console.WriteLine(name);
}

// This code produces the following output:
//
// Barley
// Boots
// Whiskers
// Bounder
// Snoopy
// Fido

' This method creates and returns an array of Pet objects.
Shared Function GetCats() As Pet()
    Dim cats() As Pet = _
        {New Pet With {.Name = "Barley", .Age = 8}, _
         New Pet With {.Name = "Boots", .Age = 4}, _
         New Pet With {.Name = "Whiskers", .Age = 1}}

    Return cats
End Function

' This method creates and returns an array of Pet objects.
Shared Function GetDogs() As Pet()
    Dim dogs() As Pet = _
        {New Pet With {.Name = "Bounder", .Age = 3}, _
         New Pet With {.Name = "Snoopy", .Age = 14}, _
         New Pet With {.Name = "Fido", .Age = 9}}

    Return dogs
End Function

Shared Sub ConcatEx1()
    Dim cats() As Pet = GetCats()
    Dim dogs() As Pet = GetDogs()

    ' Concatenate a collection of cat names to a
    ' collection of dog names by using Concat().
    Dim query As IEnumerable(Of String) = _
        cats.AsQueryable() _
        .Select(Function(cat) cat.Name) _
        .Concat(dogs.Select(Function(dog) dog.Name))

    For Each name As String In query
        MsgBox(name)
    Next
End Sub

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

' This code produces the following output:
'
' Barley
' Boots
' Whiskers
' Bounder
' Snoopy
' Fido

Kommentarer

Metoden Concat<TSource>(IQueryable<TSource>, IEnumerable<TSource>) genererar en MethodCallExpression som representerar att anropa Concat<TSource>(IQueryable<TSource>, IEnumerable<TSource>) sig själv som en konstruerad generisk metod. Den skickar sedan till MethodCallExpression metoden för den CreateQuery<TElement>(Expression) som representeras av IQueryProvider egenskapen för parameternProvider.source1

Frågebeteendet som uppstår till följd av att ett uttrycksträd som representerar anrop Concat<TSource>(IQueryable<TSource>, IEnumerable<TSource>) körs beror på implementeringen av source1 parametertypen. Det förväntade beteendet är att elementen i source2 sammanfogas med elementen source1 i för att skapa en ny sekvens.