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Queryable.AsQueryable(Of TElement) Method (IEnumerable(Of TElement))

Converts a generic IEnumerable(Of T) to a generic IQueryable(Of T).

Namespace:  System.Linq
Assembly:  System.Core (in System.Core.dll)

'Declaration
<ExtensionAttribute> _
Public Shared Function AsQueryable(Of TElement) ( _
	source As IEnumerable(Of TElement) _
) As IQueryable(Of TElement)

Type Parameters

TElement

The type of the elements of source.

Parameters

source
Type: System.Collections.Generic.IEnumerable(Of TElement)
A sequence to convert.

Return Value

Type: System.Linq.IQueryable(Of TElement)
An IQueryable(Of T) that represents the input sequence.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IEnumerable(Of TElement). When you use instance method syntax to call this method, omit the first parameter.

ExceptionCondition
ArgumentNullException

source is Nothing.

If the type of source implements IQueryable(Of T), AsQueryable(Of TElement)(IEnumerable(Of TElement)) returns it directly. Otherwise, it returns an IQueryable(Of T) that executes queries by calling the equivalent query operator methods in Enumerable instead of those in Queryable.

The following code example demonstrates how to use AsQueryable(Of TElement)(IEnumerable(Of TElement)) to convert an IEnumerable(Of T) to an IQueryable(Of T).


      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

      outputBlock.Text &= "The NodeType of the expression tree is: " _
          & expressionTree.NodeType.ToString() & vbCrLf
      outputBlock.Text &= "The Type of the expression tree is: " _
          & expressionTree.Type.Name & vbCrLf

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



Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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