关于CHECKBOX1

Sample code
========================================
REPORT  ztest NO STANDARD PAGE HEADING.
* ALV
TYPE-POOLS: slis.

TYPES: BEGIN OF ty_data,
        key  TYPE char10,
        text TYPE char40,
        mark,
     END OF ty_data.
DATA: gt_fieldcat TYPE slis_t_fieldcat_alv,
     gs_layout   TYPE slis_layout_alv.

* Data to be displayed
DATA: gt_data TYPE TABLE OF ty_data WITH KEY key WITH HEADER LINE.

*---------------------------------------------------------------------*
INITIALIZATION.
 PERFORM e01_fieldcat_init  USING gt_fieldcat[].
 .
*---------------------------------------------------------------------*
START-OF-SELECTION.
 PERFORM selection.

*---------------------------------------------------------------------*
END-OF-SELECTION.
 gs_layout-box_fieldname = 'MARK'.
 CALL FUNCTION 'REUSE_ALV_LIST_DISPLAY'
   EXPORTING
     i_callback_program      = sy-repid
     is_layout               = gs_layout
     it_fieldcat             = gt_fieldcat[]
   TABLES
     t_outtab                = gt_data
   EXCEPTIONS
     program_error           = 1
     OTHERS                  = 2.

*---------------------------------------------------------------------*
*  -->  E01_LT_FIELDCAT                                               *
*---------------------------------------------------------------------*
FORM e01_fieldcat_init USING e01_lt_fieldcat TYPE slis_t_fieldcat_alv.
 DATA: ls_fieldcat TYPE slis_fieldcat_alv.

* Key
 CLEAR ls_fieldcat.
 ls_fieldcat-fieldname    = 'KEY'.
 ls_fieldcat-tabname      = 'GT_DATA'.
 ls_fieldcat-reptext_ddic = 'KEY'.
 ls_fieldcat-outputlen    = 10.
 APPEND ls_fieldcat TO e01_lt_fieldcat.

* Text
 CLEAR ls_fieldcat.
 ls_fieldcat-fieldname    = 'TEXT'.
 ls_fieldcat-tabname      = 'GT_DATA'.
 ls_fieldcat-reptext_ddic = 'Text'.
 ls_fieldcat-outputlen    = 40.

 APPEND ls_fieldcat TO e01_lt_fieldcat.
ENDFORM.                    "e01_fieldcat_init
*---------------------------------------------------------------------*
*       FORM SELECTION                                                *
*---------------------------------------------------------------------*
*       ........                                                      *
*---------------------------------------------------------------------*
FORM selection.
 gt_data-key  = 'Group 1'.  gt_data-text = 'This is group 1'.  gt_data-mark = '0'.
 APPEND gt_data.

 gt_data-key  = 'Group 1'.  gt_data-text = 'This is group 1'.  gt_data-mark = 'X'.
 APPEND gt_data.

 gt_data-key  = 'Group 2'.  gt_data-text = 'This is group 2'.  gt_data-mark = '1'.
 APPEND gt_data.
 gt_data-key  = 'Group 2'.  gt_data-text = 'This is group 2'.  gt_data-mark = space.
 APPEND gt_data.
ENDFORM.                    "selection