DOCERR: NewIndex Property of Lists Doesn't Work as Documented

ID: Q149182

3.00 3.00b WINDOWS kbref kbdocerr

The information in this article applies to:

Microsoft Visual FoxPro for Windows, versions 3.0, 3.0b

SUMMARY

The Help file describes the NewIndex property of the ListBox and ComboBox controls thus:

   Specifies the index of the item most recently added to a ComboBox or
   ListBox control.

Then, later in the same topic, it continues:

   The NewIndex property is especially useful when adding items to a
   sorted list.

The NewIndex property does not work this way when new items are added to a sorted list. If a list is not sorted, the property simply returns the number of the last item in the list because it will always be the index of the last item added.

MORE INFORMATION

If you need to use a sorted list, you can use the ItemIdtoIndex with in conjunction with the NewItemID property, which does work as expected.

According to Help, if you add an item to a sorted list or combo box, NewIndex returns the number of the most recently added item. But this is not the case. Instead, it returns the number of the last item in the list, regardless of whether the list is sorted or not.

Steps to Reproduce Behavior

1. Create a new form, and place a combo box on the form.

2. Type the following in the Init event of the combo box:

   THIS.Sorted = .T.    && you can try it with Sorted either .T. or .F.
   SET STEP ON          && to bring up the Trace window, allow stepping.
   THIS.AddItem('AAA')  && Adds 'AAA' to the list
   THIS.AddItem('BBB')  && Adds 'BBB' to the list
   THIS.AddItem('CCC')  && Adds 'CCC' to the list
   THIS.AddItem('ABC')  && If Sorted = .T., it should insert 'ABC' into
                         * the list between item 'AAA' and item 'BBB' and
                         * NewIndex should be 2.
                         * If Sorted = .F., it should append 'ABC' to
                         * the list and NewIndex should be 4.
   THIS.AddItem('DDD')  && Adds 'DDD' to the list
   THIS.AddItem('EEE')  && Adds 'EEE' to the list

3. Place a command button on the form, and place the following code in its

   Click event:

   THISFORM.Combo1.AddItem('BCD')
   * If Sorted = .T, it should insert 'BCD' into the list between item
   * 'BBB' and item 'CCC'. NewIndex should be 4.
   ? THISFORM.Combo1.ItemIdtoIndex(THISFORM.combo1.NewItemID)

3. On the Program menu, click Debug, and enter the following lines into

   the Debug window:

   THISFORM.Combo1.NewIndex
   _SCREEN.ActiveForm.Combo1.NewIndex

4. Run the form, and use the Step menu item in the Trace window to step

   through each of the commands as you watch the value of
   THISFORM.Combo1.NewIndex change.

5. Click the button on the form. Notice that the value displayed on the

   form is 4 if the Sorted property is true (.T.) while the Value displayed
   in the Debug Window for NewIndex is 7.

NOTE: If you have THIS.Sorted set to true (.T.), NewIndex does not so indicate when item 'ABC' is inserted into position 2 of the list.

Additional reference words: 3.00 3.00b VFoxWin KBCategory: kbref kbdocerr KBSubcategory: FxotherDochelp

Keywords          : FxotherDochelp 
Version           : 3.00 3.00b
Platform          : WINDOWS