Queryable.AsQueryable Methode

Definitie

Naamruimte:
System.Linq
Assembly's:
System.Core.dll, System.Linq.Queryable.dll
Assembly's:
netstandard.dll, System.Linq.Queryable.dll
Assembly:
System.Linq.Queryable.dll
Assembly:
System.Core.dll
Assembly:
netstandard.dll

Overloads

Name Description
AsQueryable(IEnumerable)

Converteert een IEnumerable naar een IQueryable.
AsQueryable<TElement>(IEnumerable<TElement>)

Converteert een algemeen IEnumerable<T> naar een algemeen IQueryable<T>.

AsQueryable(IEnumerable)

Bron:
Queryable.cs
Bron:
Queryable.cs
Bron:
Queryable.cs
Bron:
Queryable.cs
Bron:
Queryable.cs

Converteert een IEnumerable naar een IQueryable.

public:
[System::Runtime::CompilerServices::Extension]
 static System::Linq::IQueryable ^ AsQueryable(System::Collections::IEnumerable ^ source);
public static System.Linq.IQueryable AsQueryable(this System.Collections.IEnumerable source);
[System.Diagnostics.CodeAnalysis.RequiresDynamicCode("Enumerating in-memory collections as IQueryable can require creating new generic types or methods, which requires creating code at runtime. This may not work when AOT compiling.")]
[System.Diagnostics.CodeAnalysis.RequiresUnreferencedCode("Enumerating in-memory collections as IQueryable can require unreferenced code because expressions referencing IQueryable extension methods can get rebound to IEnumerable extension methods. The IEnumerable extension methods could be trimmed causing the application to fail at runtime.")]
public static System.Linq.IQueryable AsQueryable(this System.Collections.IEnumerable source);
[System.Diagnostics.CodeAnalysis.RequiresUnreferencedCode("Enumerating in-memory collections as IQueryable can require unreferenced code because expressions referencing IQueryable extension methods can get rebound to IEnumerable extension methods. The IEnumerable extension methods could be trimmed causing the application to fail at runtime.")]
public static System.Linq.IQueryable AsQueryable(this System.Collections.IEnumerable source);
[System.Diagnostics.CodeAnalysis.RequiresUnreferencedCode("Enumerating in-memory collections as IQueryable can require unreferenced code because expressions referencing IQueryable extension methods can get rebound to IEnumerable extension methods. The IEnumerable extension methods could be trimmed causing the application to fail at runtime.")]
[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 AsQueryable(this System.Collections.IEnumerable source);
static member AsQueryable : System.Collections.IEnumerable -> System.Linq.IQueryable
[<System.Diagnostics.CodeAnalysis.RequiresDynamicCode("Enumerating in-memory collections as IQueryable can require creating new generic types or methods, which requires creating code at runtime. This may not work when AOT compiling.")>]
[<System.Diagnostics.CodeAnalysis.RequiresUnreferencedCode("Enumerating in-memory collections as IQueryable can require unreferenced code because expressions referencing IQueryable extension methods can get rebound to IEnumerable extension methods. The IEnumerable extension methods could be trimmed causing the application to fail at runtime.")>]
static member AsQueryable : System.Collections.IEnumerable -> System.Linq.IQueryable
[<System.Diagnostics.CodeAnalysis.RequiresUnreferencedCode("Enumerating in-memory collections as IQueryable can require unreferenced code because expressions referencing IQueryable extension methods can get rebound to IEnumerable extension methods. The IEnumerable extension methods could be trimmed causing the application to fail at runtime.")>]
static member AsQueryable : System.Collections.IEnumerable -> System.Linq.IQueryable
[<System.Diagnostics.CodeAnalysis.RequiresUnreferencedCode("Enumerating in-memory collections as IQueryable can require unreferenced code because expressions referencing IQueryable extension methods can get rebound to IEnumerable extension methods. The IEnumerable extension methods could be trimmed causing the application to fail at runtime.")>]
[<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 AsQueryable : System.Collections.IEnumerable -> System.Linq.IQueryable
<Extension()>
Public Function AsQueryable (source As IEnumerable) As IQueryable

Parameters

source
IEnumerable

Een reeks die moet worden geconverteerd.

Retouren

IQueryable

Een IQueryable die de invoerreeks vertegenwoordigt.

Kenmerken
RequiresDynamicCodeAttribute RequiresUnreferencedCodeAttribute

Uitzonderingen

ArgumentException

source implementeert niet IEnumerable<T> voor sommige T.

ArgumentNullException

source is null.

Opmerkingen

Als het type source implementaties IQueryable<T>rechtstreeks AsQueryable(IEnumerable) retourneert. Anders wordt een IQueryable<T> query geretourneerd die query's uitvoert door de equivalente queryoperatormethoden aan te roepen in Enumerable plaats van die in Queryable.

Bij deze methode wordt ervan uitgegaan dat source deze IEnumerable<T> implementeert voor sommige T. Tijdens runtime is het resultaat van het type IQueryable<T> voor hetzelfde T. Deze methode is handig in dynamische scenario's wanneer u het type Tniet statisch kent.

Van toepassing op

AsQueryable<TElement>(IEnumerable<TElement>)

Bron:
Queryable.cs
Bron:
Queryable.cs
Bron:
Queryable.cs
Bron:
Queryable.cs
Bron:
Queryable.cs

Converteert een algemeen IEnumerable<T> naar een algemeen IQueryable<T>.

public:
generic <typename TElement>
[System::Runtime::CompilerServices::Extension]
 static System::Linq::IQueryable<TElement> ^ AsQueryable(System::Collections::Generic::IEnumerable<TElement> ^ source);
public static System.Linq.IQueryable<TElement> AsQueryable<TElement>(this System.Collections.Generic.IEnumerable<TElement> source);
[System.Diagnostics.CodeAnalysis.RequiresDynamicCode("Enumerating in-memory collections as IQueryable can require creating new generic types or methods, which requires creating code at runtime. This may not work when AOT compiling.")]
[System.Diagnostics.CodeAnalysis.RequiresUnreferencedCode("Enumerating in-memory collections as IQueryable can require unreferenced code because expressions referencing IQueryable extension methods can get rebound to IEnumerable extension methods. The IEnumerable extension methods could be trimmed causing the application to fail at runtime.")]
public static System.Linq.IQueryable<TElement> AsQueryable<TElement>(this System.Collections.Generic.IEnumerable<TElement> source);
[System.Diagnostics.CodeAnalysis.RequiresUnreferencedCode("Enumerating in-memory collections as IQueryable can require unreferenced code because expressions referencing IQueryable extension methods can get rebound to IEnumerable extension methods. The IEnumerable extension methods could be trimmed causing the application to fail at runtime.")]
public static System.Linq.IQueryable<TElement> AsQueryable<TElement>(this System.Collections.Generic.IEnumerable<TElement> source);
[System.Diagnostics.CodeAnalysis.RequiresUnreferencedCode("Enumerating in-memory collections as IQueryable can require unreferenced code because expressions referencing IQueryable extension methods can get rebound to IEnumerable extension methods. The IEnumerable extension methods could be trimmed causing the application to fail at runtime.")]
[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<TElement> AsQueryable<TElement>(this System.Collections.Generic.IEnumerable<TElement> source);
static member AsQueryable : seq<'Element> -> System.Linq.IQueryable<'Element>
[<System.Diagnostics.CodeAnalysis.RequiresDynamicCode("Enumerating in-memory collections as IQueryable can require creating new generic types or methods, which requires creating code at runtime. This may not work when AOT compiling.")>]
[<System.Diagnostics.CodeAnalysis.RequiresUnreferencedCode("Enumerating in-memory collections as IQueryable can require unreferenced code because expressions referencing IQueryable extension methods can get rebound to IEnumerable extension methods. The IEnumerable extension methods could be trimmed causing the application to fail at runtime.")>]
static member AsQueryable : seq<'Element> -> System.Linq.IQueryable<'Element>
[<System.Diagnostics.CodeAnalysis.RequiresUnreferencedCode("Enumerating in-memory collections as IQueryable can require unreferenced code because expressions referencing IQueryable extension methods can get rebound to IEnumerable extension methods. The IEnumerable extension methods could be trimmed causing the application to fail at runtime.")>]
static member AsQueryable : seq<'Element> -> System.Linq.IQueryable<'Element>
[<System.Diagnostics.CodeAnalysis.RequiresUnreferencedCode("Enumerating in-memory collections as IQueryable can require unreferenced code because expressions referencing IQueryable extension methods can get rebound to IEnumerable extension methods. The IEnumerable extension methods could be trimmed causing the application to fail at runtime.")>]
[<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 AsQueryable : seq<'Element> -> System.Linq.IQueryable<'Element>
<Extension()>
Public Function AsQueryable(Of TElement) (source As IEnumerable(Of TElement)) As IQueryable(Of TElement)

Type parameters

TElement

Het type van de elementen van source.

Parameters

source
IEnumerable<TElement>

Een reeks die moet worden geconverteerd.

Retouren

IQueryable<TElement>

Een IQueryable<T> die de invoerreeks vertegenwoordigt.

Kenmerken
RequiresDynamicCodeAttribute RequiresUnreferencedCodeAttribute

Uitzonderingen

ArgumentNullException

source is null.

Voorbeelden

In het volgende codevoorbeeld ziet u hoe u een kunt converteren AsQueryable<TElement>(IEnumerable<TElement>) naar een IEnumerable<T>.IQueryable<T>

List<int> grades = new List<int> { 78, 92, 100, 37, 81 };

// Convert the List to an IQueryable<int>.
IQueryable<int> iqueryable = grades.AsQueryable();

// Get the Expression property of the IQueryable object.
System.Linq.Expressions.Expression expressionTree =
    iqueryable.Expression;

Console.WriteLine("The NodeType of the expression tree is: "
    + expressionTree.NodeType.ToString());
Console.WriteLine("The Type of the expression tree is: "
    + expressionTree.Type.Name);

/*
    This code produces the following output:

    The NodeType of the expression tree is: Constant
    The Type of the expression tree is: EnumerableQuery`1
*/

Dim grades As New List(Of Integer)(New Integer() {78, 92, 100, 37, 81})

' Convert the List to an IQueryable<int>.
Dim iqueryable As IQueryable(Of Integer) = grades.AsQueryable()

' Get the Expression property of the IQueryable object.
Dim expressionTree As System.Linq.Expressions.Expression = _
    iqueryable.Expression

MsgBox("The NodeType of the expression tree is: " _
    & expressionTree.NodeType.ToString())
MsgBox("The Type of the expression tree is: " _
    & expressionTree.Type.Name)

' This code produces the following output:
'
' The NodeType of the expression tree is: Constant
' The Type of the expression tree is: EnumerableQuery`1

Opmerkingen

Als het type source implementaties IQueryable<T>rechtstreeks AsQueryable<TElement>(IEnumerable<TElement>) retourneert. Anders wordt een IQueryable<T> query geretourneerd die query's uitvoert door de equivalente queryoperatormethoden aan te roepen in Enumerable plaats van die in Queryable.

Van toepassing op