You can define and subclass the DataEnvironment class. From a form, you can save the existing data environment as a visual class library (.vcx) file by selecting the form, choosing Save As Class from the File menu, and selecting DataEnvironment. All DataEnvironment properties, methods, and events are available as appropriate in the Properties window after you open the Class Designer. However, you can access the Data Environment Designer only from the Form Designer, not from the Class Designer.

At design time, you can add a preexisting DataEnvironment class to a form from a class library toolbar or in code using the AddObject method. However, Visual FoxPro considers the DataEnvironment class added in either manner as a member class, not a native data environment.

You can use the FormВ DEClass and DEClassLibrary properties to specify and load an external DataEnvironment class at design time or run time. Visual FoxPro supports the DEClass and DEClassLibrary properties for form (.scx), visual class library (.vcx), and program (.prg) files but not for form sets or in the Report Designer.

For more information, see the DEClass Property and DEClassLibrary Property properties. For more information about the data environment for forms and form sets, see Creating Forms.