How to Update a Table from a List Box with Mover Bars

• Microsoft Visual FoxPro for Windows, version 3.0

SUMMARY

This article shows by example how to create a list box with mover bars that will update a table. The example creates a two-field table of cities and their original numeric position in the table. The list box mover bars facilitate moving the items in the list to a different position and updating the position number in the table. Mover bars are only available with a RowSourceType of either 0 (None) or 1 (Value).

MORE INFORMATION

The following program creates a table and a form with a list box. The list box has mover bars that can be used to move the items in the list. When the item is moved, its list number changes as indicated by the grid display.

Code Sample

***START of the MoverBar Program * * Change the following lines up to the next set of * asterisks into comments to prevent creating a new table each * time this program is executed.

SELECT DISTINCT city, 100 ; FROM SYS(2004)+"\samples\data\customer" ; INTO table MyCity

REPLACE ALL exp_2 WITH RECNO() GO TOP **************** frmMoverBar = CREATEOBJECT("moverbar") frmMoverBar.show

READ EVENTS RELEASE ALL

**************************************************

*-- Class:        moverbar

*-- BaseClass:    form
*

     Top       = 3
     Left      = 17
     Height    = 275
     Width     = 500
     DoCreate  = .T.
     Caption   = "Mover Bar Example"
     Name      = "frmMoverBarForm1"

     ADD Object grdMyCity AS Grid With ;
          Columncount      = 2, ;
          Height           = 175, ;
          Left             = 225, ;
          Recordsource     = "MyCity", ;
          Recordsourcetype = 1, ;
          Top              = 24, ;
          Width            = 250


     ADD OBJECT lstList1 AS Listbox WITH ;
          ColumnCount      = 2, ;
          ColumnWidths     = "100,50", ;
          RowSourceType    = 0, ;
          RowSource        = "", ;
          Height           = 175, ;
          Left             = 30, ;
          MoverBars        = .T., ;
          Top              = 24, ;
          Width            = 175, ;
          Name             = "lstList1"

     ADD OBJECT cmdCommand1 AS commandbutton WITH ;
          Top     = 216, ;
          Left    = 400, ;
          Height  = 29, ;
          Width   = 75, ;
          Caption = "Exit", ;
          Name    = "CmdCommand1"

     PROCEDURE lstList1.InteractiveChange
          SELECT MyCity

          FOR i = 1 TO ThisForm.lstList1.Listcount
               LOCATE FOR city = ThisForm.lstList1.List(i)
               REPLACE exp_2 WITH i
               ThisForm.lstList1.List(i,2)=ALLTRIM(STR(i))
          ENDFOR

          GO TOP
     ENDPROC

     PROCEDURE lstList1.Init
          SELECT city,exp_2 FROM MyCity INTO cursor x ORDER BY 2

          i=0
          SCAN
               i=i+1
               This.AddItem(city,i,1)
               This.AddListItem(ALLTRIM(STR(exp_2)),i,2)
          ENDSCAN
     ENDPROC

     PROCEDURE CmdCommand1.Click
          SELECT MyCity
          USE
          ERASE mycity.dbf  &&Comment this line in order to save the table.
          CLEAR EVENTS

     ENDPROC