程序代码：

** listbox 复选
of = CREATEOBJECT("form1")
of.show(1)

DEFINE CLASS form1 as Form
    ADD OBJECT list1 as myListbox WITH left=10,top=10
ENDDEFINE

DEFINE CLASS myListbox as listbox
    width                 = 250
    height                = 200
    ColumnCount           = 2
    ColumnLines           = .f.
    RowSourceType         = 0
    FontSize              = 12
    SelectedItemBackColor = 0x00C0C0C0
    SelectedItemForeColor = 0
    
    PROCEDURE init
        FOR i=1 TO 9
            this.AddListitem("○")    && ○●
            this.AddListItem(REPLICATE(TRANSFORM(i),20), this.NewItemID, 2)
        ENDFOR 
    ENDPROC

    PROCEDURE click
        this.List(this.ListIndex,1) = IIF(this.List(this.ListIndex,1)=="○", "●", "○")
    ENDPROC 
ENDDEFINE