The information in this article applies to:
- Microsoft Visual FoxPro for Windows, version 3.0
SUMMARY
This article gives details about how to create and use custom methods.
In FoxPro version 2.x, you can define procedures and functions in the
cleanup code of FoxPro version 2.x screens. Forms in Visual FoxPro don't
have an analogous place for defining procedures and functions, so you can:
- Put cleanup code in a procedure file contained in the Project Manager,
and issue a SET PROCEDURE TO statement.
-or-
- Create functions and procedures as custom methods of the form. These
custom methods can then be referenced the same as any other method of
the form or other object.
MORE INFORMATION
Custom methods can be coded to behave as functions behave; that is, they
can return a value simply by ending the code definition with RETURN x
where x is the name of a variable whose value is set in the method.
Custom methods should not begin with the PROCEDURE or FUNCTION command,
which is normally used to indicate that a procedure or function is being
defined, nor should they end with ENDPROC or ENDFUNC.
Step-by-Step Example
- Create a new form, and add two text boxes (Text1 and Text2) and two
command buttons (Command1 and Command2).
- Add the Customer and Orders tables from the Testdata database to the
data environment of the form.
- Set the ControlSource for the Text1 box to:
customer.cust_id
- Set the ReadOnly property for the Text1 box to True (.T.).
- Leave the ControlSource property for the Text2 box blank.
- On the Form menu, click New Method. Enter Custcount as the name of the
new method.
- Change the caption of the Command1 button to "Count orders," and enter
the following code in the Click event procedure:
nNum = thisform.custcount()
thisform.text2.value = nNum
thisform.refresh
- Change the caption of the Command2 button to Skip, and enter the
following code in the Click event procedure:
skip
thisform.refresh
- Enter the following code for the Custcount custom method:
x = 0
select orders
go top
count to x for orders.cust_id = thisform.text1.value
select customer
return x
When you click the Count orders button, the Custcount custom method is
called to count how many orders exist in the Orders table for the current
record in the Customer table. This number is returned to the Count orders
button.