How to Create a Multiple-Select Mover List Box Using Code

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

SUMMARY

In many examples and documentation showing the List Control in Visual FoxPro, you may see a mover list or multiple-select mover list shown. To see the code for a mover list box, type the following command in the Command window, and select Sample.vcx in the open dialog window:

   MODIFY CLASS ? OF C:\Vfp\Samples\Controls\Samples.vcx

MORE INFORMATION

The following code creates a mover list box that stores the field names of a table in a list box. The values can then be moved into a second list box. A BROWSE FIELDS statement is then issued based on the contents of the second list box.

Step-by-Step Example

1. Create a new form, and add a table to the Data Environment.

2. Set the AutoOpenTables and the AutoCloseTables properties values in the Data Environment to false (.F.).

3. Place the following code in the Init event of the form:

      PUBLIC blist        && variable used in the Browse Button
      blist=''
      USE <tablename>
      FOR gnCount = 1 TO FCOUNT( )   && Loop for number of fields
         THISform.list1.ADDITEM(Field(gnCount))
      NEXT
   
   

4. Place the following code in the Doubleclick event of the List1 box:

   Thisform.Lockscreen=.T. nCnt = 1 DO WHILE nCnt <= Thisform.List1.ListCount

         IF Thisform.List1.Selected(nCnt)
            Thisform.List2.AddItem(Thisform.List1.List(nCnt))
            Thisform.List1.RemoveItem(nCnt)
         ELSE
            nCnt = nCnt + 1
         ENDIF
      ENDDO
      Thisform.Lockscreen=.F.
   
   

5. Place the following code in the Doubleclick event of the List2 box:

   Thisform.Lockscreen=.T. nCnt = 1 DO WHILE nCnt <= thisform.list2.ListCount

         IF Thisform.List2.Selected(nCnt)
            Thisform.List1.AddItem(Thisform.List2.List(nCnt))
            Thisform.List2.RemoveItem(nCnt)
         ELSE
            nCnt = nCnt + 1
         ENDIF
      ENDDO
      Thisform.Lockscreen=.F.
   
   

6. Place the following code in the Click event of a command button to move a selection from List1 to List2 ( > ):

   Thisform.Lockscreen=.T. cnt=Thisform.List1.Listindex IF Thisform.List1.Selected(cnt) = .T.

        nCnt = 1
        DO WHILE nCnt <= Thisform.List1.ListCount
         IF Thisform.List1.Selected(nCnt)
           Thisform.List2.AddItem(Thisform.List1.List(nCnt))
           Thisform.List1.RemoveItem(nCnt)
         ELSE
           nCnt = nCnt + 1
         ENDIF
        ENDDO
      ELSE
        =MESSAGEBOX('Please Highlight Your Choice')
      ENDIF
   
      Thisform.Lockscreen=.F.
   
   

7. Place the following code in the Click event of a command button to move all the values from the List1 to List2 ( >> ):

   Thisform.LockScreen = .T. FOR i = 1 to Thisform.List1.ListCount

         Thisform.List2.AddItem(Thisform.List1.List(i))
   

   ENDFOR Thisform.list1.Clear Thisform.LockScreen = .F.

8. Place the following code in the Click event of a command button to move a selection from List2 to List1 ( < ):

   Thisform.Lockscreen=.T. cnt=Thisform.List2.Listindex IF Thisform.List2.Selected(cnt) = .T.

         nCnt = 1
   

   DO WHILE nCnt <= Thisform.List2.ListCount

       IF Thisform.List2.Selected(nCnt)
        Thisform.List1.AddItem(Thisform.List2.List(nCnt))
        Thisform.List2.RemoveItem(nCnt)
       ELSE
        nCnt = nCnt + 1
       ENDIF
   

   ENDDO ELSE =MESSAGEBOX('Please Highlight Your Choice') ENDIF Thisform.Lockscreen=.F.

9. Place the following code in the Click event of a command button to move all the values from List2 to List1 ( << ):

   Thisform.LockScreen = .T. FOR i = 1 to thisform.list2.ListCount

        Thisform.List1.AddItem(Thisform.List2.List(i))
   

   ENDFOR Thisform.List2.Clear Thisform.LockScreen = .F.

10. Place The Following Code In The Click event of a Browse button:

        blist=''
        bval=''
        Thisform.LockScreen = .T.
        FOR x = 1 to Thisform.List2.Listcount
          IF x=1
             blist=Thisform.List2.List(x)
          ELSE
             blist=','+Thisform.List2.List(x)
          ENDIF
             bval=bval+blist
        ENDFOR
        Thisform.LockScreen = .F.
        BROWSE FIELDS &bval
    
    

11. Place the following code in the click event of an Exit button:

        USE
        Thisform.Release
    

12. Run the form.

REFERENCES

For more information about mover list boxes, please see the following article in theMicrosoft Knowledge Base:

   ARTICLE-ID: Q142190
   TITLE     : How to Create Mover List Boxes in Visual FoxPro