Subject Re: timer class From Mustansir Ghor <mustan31@hotmail.com> Date Sun, 24 Jul 2022 14:28:39 -0400 Newsgroups dbase.getting-started Dear Mervyn Sir I agree with your explanation and was aware of it but I am at development stage. Here on IDE i use design and run icons to test my form. So  thought may be  onDesign form event or somewhere I could close the form so that I dont get disrupted with the error. Yes as Andy says learning process never ends. Regards to all Mustansir Mervyn Bick Wrote: > On 2022/07/24 12:43, Mustansir Ghor wrote: > > Dear All > > > > One more issue has come up with me. > > > > After using a timer class in the form ,a statement form.databasename.emptytable(" xyz") says file is in use by another on a second attemp on form run. After 1st run when I click form design button I think due to timer, the database must not have closed. > > > > Can anybody suggest if we rectify this problem. > > It is extremely important to manually deactivate any timer object on a > form in the form's canClose or onClose event handler.  If you don't > deactivate it it keeps on ticking away in memory until you actually > close dBASE.  Type   help timer class   in the Command Panel and then > click on the link to the example at the top of the page. > > Most objects on a form are closed and released automatically when a form > is closed.  As an aside, it is good programming (although too many > programmers seem to not do this) to deactivate all objects manually > before closing a form. > > If all objects on the form are inactive when the form is closed Windows > will release the form and clear it from memory.  If anything in the form > accesses an active object in memory then Windows keeps the form in > memory.  If you open the form a second time Windows doesn't load and run > the code again it simply uses the code already in memory. > > The emptyTable() method of a database object requires exclusive use of > the table.  This means that in your form the method has to be executed > before the query that accesses the table is made active.  When Windows > executes the copy kept in memory the second time round the query is > active because it was active when the form was closed.  The table is, > therefore, in use and the emptyTable() method can't be executed. > > Mervyn. > > > > > > >