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

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

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

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

public void AsyncCountWithPredicate() {
  var op = _entityManager.Employees.AsScalarAsync().Count(e => e.BirthDate > DateTime.Parse("1/1/1955"));
  op.Completed += (o, e) => {
    var ct = e.Result;
  };
}