PRB: Can't Activate or Access an Object (132227)

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

To cancel this code, click the Command box for this form, and click Close. Then on the Visual FoxPro menu, on the Program menu, click Cancel.

MORE INFORMATION

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