PRB: "Member Column<n> is a class member" Error Message

• Microsoft Visual FoxPro for Windows, version 3.0

SYMPTOMS

Changing the ColumnCount property of a grid class, subclassed onto a form, to a value less than the one already set for the grid class when it was created results in this error:

   Member COLUMN<n> is a class member.

CAUSE

You cannot delete members from an instantiated object that are members of the base class.

STATUS

This behavior is by design.

MORE INFORMATION

When you insert a Grid class into a form, you cannot change the ColumnCount property to a value less than the one that was set when the Grid class was created. If you do so, the "Member COLUMN<n> is a class member" error message is displayed. In this error, <n> is a number that is one greater than the ColumnCount value you are trying to set for the Grid class in the form.

For example if ColumnCount for the Grid class was set to 3 when it was created, and you change it to 2, 1, or 0 when placed in a form, then the value of <n> in the error message will be 3, 2, or 1 respectively.

Steps to Reproduce Behavior

1. Create a Grid class with three columns.

2. Create a form.

3. Drop an instance of the Grid class onto the form, and populate the three-column grid.

4. Save and run the form. Everything works as expected.

5. Modify the form.

6. Change ColumnCount for the grid to 2. The error "Member COLUMN3 is a class member" is displayed.