SingleOrDefault(IEntityScalarQuery,CancellationToken) Method

Returns the only element of a sequence, or a default value if the sequence is empty; this method throws an exception if there is more than one element in the sequence. Pass in a System.Threading.CancellationToken to cancel operation.

Syntax

Visual Basic
C#

'Declaration
 
<ExtensionAttribute()>
Public Overloads Shared Function SingleOrDefault( _
   ByVal source As IEntityScalarQuery, _
   ByVal cancellationToken As CancellationToken _
) As Task(Of Object)

'Usage
 
Dim source As IEntityScalarQuery
Dim cancellationToken As CancellationToken
Dim value As Task(Of Object)
 
value = EntityScalarAsyncExtensions.SingleOrDefault(source, cancellationToken)

[Extension()]
public static Task<object> SingleOrDefault( 
   IEntityScalarQuery source,
   CancellationToken cancellationToken
)

Parameters

source
cancellationToken

Example

public async void AsyncSingleOrDefault() {
  Employee emp = await _entityManager.Employees.Where(e => e.Id == 1).AsScalarAsync().SingleOrDefault();
}

Requirements

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

EntityScalarAsyncExtensions Class
EntityScalarAsyncExtensions Members
Overload List