FirstOrNullEntity(IEntityScalarQuery,IPredicateDescription) Method

Returns the first element of a sequence that satisfies a specified condition, or the appropriate NullEntity if no such element is found.

Syntax

Visual Basic
C#

'Declaration
 
<ExtensionAttribute()>
Public Overloads Shared Function FirstOrNullEntity( _
   ByVal source As IEntityScalarQuery, _
   ByVal predicateDescription As IPredicateDescription _
) As Task

'Usage
 
Dim source As IEntityScalarQuery
Dim predicateDescription As IPredicateDescription
Dim value As Task
 
value = EntityScalarAsyncExtensions.FirstOrNullEntity(source, predicateDescription)

[Extension()]
public static Task FirstOrNullEntity( 
   IEntityScalarQuery source,
   IPredicateDescription predicateDescription
)

Parameters

source
predicateDescription

Example

public async void AsyncFirstOrNullEntityWithPredicate() {
  Employee emp = await _entityManager.Employees.AsScalarAsync().FirstOrNullEntity(e => e.LastName.StartsWith("D"));
}

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