How to Disable Combo and List Boxes in Wizard-Generated Forms

• Microsoft Visual FoxPro for Windows, version 3.0

SUMMARY

When the Form Wizard builds a form, it creates the form so that when the form runs, the objects that hold data are disabled. Clicking the Edit button enables the objects and allows editing of the information. However, if controls other than check boxes, text boxes, or OLE-bound controls are added to the form, they are enabled, not disabled, when the form is run.

This article shows you how to disable controls such as combo boxes and list boxes so that they are disabled when the form runs and enabled when the Edit button is clicked. The code that controls which objects are disabled or enabled is located in the Wizstyle.vcx form. The combo and list boxes were not included in that code, but you can modify the code to include the combo and list boxes.

MORE INFORMATION

Step-by-Step Procedure

1. On the File menu, click Open, and change Files of Type to Visual Class Library. In the \Vfp\Wizards\ directory, select Wizstyle.vcx. In the Open box, choose TXTBTNS as the Class Name. The Class Designer will appear and allow the editing of the wizard buttons.

2. Double-click any button. In the Object box, select TXTBTNS. In the Procedures box, select SETALLPROP. In this code, look for the following line (it is split here for readability):

   CASE ATC(m.oControlParent.Controls[m.i].BaseClass,

         "CheckBox,TextBox,OleBoundControl") # 0
             m.oControlParent.Controls[m.i].Enabled = THIS.EditMode
   
   

3. Note that CheckBox, TextBox, and OleBoundControl are the only objects referenced here. Add "ComboBox, ListBox, EditBox" to this line of code.

4. Save the changes, and create or open a wizard-generated form. Add a combo box based on a field from a table. When you run the form, note that the combo box is disabled until you click the Edit button.