<ExtensionAttribute()>
Public Overloads Shared Function First( _
   ByVal source As IEntityScalarQuery, _
   ByVal predicateDescription As IPredicateDescription, _
   Optional ByVal userCallback As Action(Of EntityScalarQueryOperation), _
   Optional ByVal userState As Object _
) As EntityScalarQueryOperation

Dim source As IEntityScalarQuery
Dim predicateDescription As IPredicateDescription
Dim userCallback As Action(Of EntityScalarQueryOperation)
Dim userState As Object
Dim value As EntityScalarQueryOperation
 
value = EntityScalarAsyncExtensions.First(source, predicateDescription, userCallback, userState)

[ExtensionAttribute()]
public static EntityScalarQueryOperation First( 
   IEntityScalarQuery source,
   IPredicateDescription predicateDescription,
   Action<EntityScalarQueryOperation> userCallback,
   object userState
)

[ExtensionAttribute()]
public:
static EntityScalarQueryOperation^ First( 
   IEntityScalarQuery^ source,
   IPredicateDescription^ predicateDescription,
   Action<EntityScalarQueryOperation^>^ userCallback,
   Object^ userState
) 

public void AsyncFirstWithPredicate() {
  var op = _entityManager.Employees.AsScalarAsync().First(e => e.LastName.StartsWith("D"));
  op.Completed += (o, e) => {
    var emp = e.Result;
  };
 }