<ExtensionAttribute()>
Public Overloads Shared Function Count( _
   ByVal source As IQueryable _
) As Integer

Dim source As IQueryable
Dim value As Integer
 
value = QueryableExtensions.Count(source)

[ExtensionAttribute()]
public static int Count( 
   IQueryable source
)

[ExtensionAttribute()]
public:
static int Count( 
   IQueryable^ source
) 

var mgr1 = new DomainModelEntityManager();

var entityType = typeof(Customer);
var baseQuery = EntityQuery.Create(entityType);
var count = baseQuery.Count();