USING 语句的 VBA 是什么

Question

In csharp or vb.net we use the using statement for reasons that we know: One can open the database and close it automatically without writing it explicitly. I would like to do the samething in VBA

1. how to do it?
2. Are all VB.NET statement/keywords/ available in VBA ?
3. how to tell if a given statement is(was) known in VBA ? Is it there a library(glosary) of all VBA statements/keyword/operators ?

c#

  using(var db=new MyDbContext()){
   //do work here
  }

vb.net

    Using s = New MyDbContext()
     '--..do work here
    End Using

Answer 1

Answering just your first question, as you've hinted, Using is just syntactic sugar for calling Dispose() on an object instance which implements the IDisposable interface.

It is equivalent to

Dim s as MyDbContext
Try
   s = New MyDbContext()
   // ...
Finally
   s.Dispose()
End Try

Since VBA doesn't support the Using sugar, and in the absence of structured Try..Catch exception handling, you'll need to explicitly call Dispose() on all paths which control the lifespan of the object ( MyDbContext in your case). In which case you may as well have just used .Close()

Answer 2

There is no VBA equivalent to the Using statement.

The VBA developer documentation provides samples and even downloadable offline versions of the VBA documentation.