PRB: Can't Activate or Access an Object

ID: Q132227

The information in this article applies to:

• Microsoft Visual FoxPro for Windows, version 3.0

SYMPTOMS

After you define a class in a program (.PRG file) and run it, nothing happens. For example, the following code, when run in a .PRG file, executes and return to the Command window:

   DEFINE CLASS myform AS form
         ADD OBJECT cmd1 as commandbutton WITH ;
                 top = 10, ;
                 left = 10
   ENDDEFINE

CAUSE

A class is simply a template or definition from which an object will be created. Defining a class does not create an instance of the class.

RESOLUTION

Building on the example above, the code example creates a template from which a new object can be created. To instantiate the defined class, you must add this additional code:

   PUBLIC MyForm
   MyForm = CREATEOBJECT("MyForm")  && Create a new object
   MyForm.Show                      && Show the form
   Read Events                      && Keep the event loop alive

   DEFINE CLASS myform AS form
      ADD OBJECT cmd1 as commandbutton WITH ;
         top  = 60, ;
         left = 60
   ENDDEFINE

STATUS

This behavior is by design.

MORE INFORMATION

For additional information on objects and classes, please see these Help topics:

• Class, defined.
• Instance, defined.