How to Fill Second List with Values from Multiselect List Box

• Microsoft Visual FoxPro for Windows, versions 3.0 and 3.0b

SUMMARY

When using multiple page pageframes, you may find it useful to populate a list box on a following page with the values selected from a multiple- select list box on a previous page.

This article demonstrates how to fill the first multiple-select list box from an array created by an SQL SELECT statement and then take the user's selections from this list box to fill the second list box on another page of the pageframe.

The form has a command button that resets the multiple-select list so that the user can start making selections on a clean unselected list. Initially, this button is disabled; it becomes enabled when at least one selection is made in the multiple-select list box. When the user clicks the button to reset the list, the command button again becomes disabled.

The form also checks whether a selection was made on the first list. If no items are chosen in the first list, the display value of the second list shows "No Selection Made" in the list. This feature is optional.

MORE INFORMATION

NOTE: To select multiple items from a multiple-select list, hold down the CTRL key while clicking with the mouse. To select a contiguous range of items, click first item in the range, and then hold down the SHIFT key as you click the last item.

Step-by-Step Example

1. Create a new form.

2. In the form designer, choose New Property from the Form menu. Enter the following array in the name box. Then click OK:

   aSelected(1)

   Again choose New Property from the Form menu. Enter the variable that will be used to count the selected items in the name box. Then click OK:

   nCount

3. Right-click the form, and select Data Environment. Then right-click the Data Environment window, and click Add. Click the Other button, and add the Employee table from the \VFP\Samples\Data directory.

4. Add a page frame to the form by selecting the PageFrame control from the Form Controls toolbar and clicking the form. Resize the page frame if needed.

5. Right-click the page frame, and select Edit. A hatched border is drawn around the page frame.

6. Right-click Page1 and select Properties. Select the All tab from the Properties sheet, and add the following code to the listed events for Page1 of the page frame:

   Activate event:

      Thisform.nCount=0                 && Reset nCount when page is selected
      Thisform.aSelected=" "            && Reinitialize array to empty string
      DIMENSION Thisform.aSelected(1)   && Redimension array to one element
   
      FOR i=1 TO This.List1.ListCount   && Loop through number items in List
         IF This.List1.Selected=.T.     && If an item is selected in List,
            This.List1.Selected=.F.     && the Selected property is .T.
         ENDIF
      ENDFOR
   
      This.List1.ListIndex=0            && Reset the index number of List box
      This.List1.RowSource=This.List1.RowSource
      This.Refresh                      && Force List and Form to refresh
   
      Deactivate event:
   
      This.Command1.Enabled=.F.
      LOCAL narraycnt
      narraycnt=1
   
      FOR i=1 TO This.List1.ListCount    && Loop through Selected array, if
         IF This.List1.Selected(i)=.T.   && true, increment nCount variable.
            Thisform.nCount=Thisform.nCount+1
         ENDIF
      ENDFOR
   
      IF Thisform.nCount=0               && No selection made, set nCount=1
         Thisform.nCount=1
         Thisform.aSelected(Thisform.nCount)="No Selection Made!"
      ENDIF
   
      DIMENSION Thisform.aSelected(Thisform.nCount)  && Dimension array
   
      FOR i=1 TO This.List1.Listcount     && Loop through items in List,
         IF This.List1.Selected(i)=.T.    && if Selected-look at List property
            Thisform.aSelected(narraycnt)=This.List1.List(i)
            narraycnt=narraycnt+1
         ENDIF
      ENDFOR
   
   

7. With the pageframe still in edit mode, add a list box to Page1 of the page frame by selecting the ListBox control from the Form Controls toolbar and clicking Page1.

8. Right-click the list box and select Properties, or click the Properties window if it is already available. Select the All tab from the Properties sheet, and modify the following properties and events:

   RowSource - Enter the following on one, single line:

   SELECT DISTINCT Employee.Title from Testdata!Employee ORDER BY

         Employee.Title INTO CURSOR mlist WHERE NOT EMPTY(Employee.Title)
   

   RowSourceType: 3 - SQL Statement

   MultiSelect: .T.

   Click Event:

      This.Parent.Command1.Enabled=.T.           &&  Enable 'RESET' button
   
   

9. Add a command button to page 1 while the page frame is in edit mode. Configure the command button with the following properties and events:

   Caption: Reset List

   Click Event:

      This.Parent.List1.ListIndex=0            &&  Reset ListIndex property
      This.Parent.List1.RowSource=This.Parent.List1.RowSource
      This.Parent.Refresh                      &&  Refresh List and Page
      This.Enabled=.F.                         &&  Disable 'RESET' button
      This.Parent.List1.Setfocus               && Put focus on list
   
   

10. With the page frame in edit mode, click the Page2 tab on the page

        frame.  Add the following events to Page2 of the pageframe:
    

        Activate event:
    

        This.List1.Requery             && Issue Requery to display/refresh
    
    

11. Add a list box to Page2 with the following properties:

        RowSource: Thisform.aSelected
    

        RowSourceType: 5 - Array