DOCUMENT:Q136588 10-AUG-1999 [foxpro] TITLE :PRB: List Boxes and Combo Boxes Lose Item Properties PRODUCT :Microsoft FoxPro PROD/VER:3.0 OPER/SYS: KEYWORDS:kbvfp ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Visual FoxPro for Windows, version 3.0 ------------------------------------------------------------------------------- SYMPTOMS ======== When the RowSource property of a ComboBox or ListBox control is set to a value other than 0-None and there are many items in the list, properties of individual items are lost when you scroll down the list. For example, if you select several items from the list, scroll down the list, and then scroll up the list, the selected items might not be highlighted anymore. CAUSE ===== This behavior is due to architectural limitations in the manager that handles the lists. When the RowSource is non-zero, the list manager creates 60 items internally and recycles them. This improves performance for lists that have a large number of items. For example, if a list is populated with a million-row table, Visual FoxPro does not have to take the speed and memory penalty associated with creating a million list items. Because they are recycled, properties set on the items are lost during operations such as scrolling. This behavior does not occur in Visual FoxPro 5.0. RESOLUTION ========== Populate the controls with the AddItem and RemoveItem methods. These methods create non-recyclable items that are guaranteed to retain their properties. STATUS ====== This behavior is by design. MORE INFORMATION ================ Steps to Reproduce Behavior --------------------------- 1. Place a List box control on a form and add the \VFP\SAMPLES\DATA\Customer table to the Data Environment. 2. Change the properties of the list box as follows: RowSourceType = 6 RowSource = "customer.contact" MultiSelect = .T. 3. Run the form and click an item in the list box. Press and hold down the SHIFT key and then press the DOWN ARROW key to select another item in the list box. Now, scroll down the list box to the last item and then scroll back up to the top of the list box. Note that the items are no longer selected. Additional query words: List box ====================================================================== Keywords : kbvfp Technology : kbVFPsearch kbAudDeveloper kbVFP300 Version : 3.0 Issue type : kbprb ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 1999.