ABAP ALV refresh_table_display问题

问题就是，内表的数据没刷新出来

代码如下：

FORM frm_command USING i_ucomm       TYPE sy-ucomm
                        selfield TYPE slis_selfield.
  DATA: ls_stbl TYPE lvc_s_stbl.

  ls_stbl-row = 'X'. "基于行的稳定刷新
  ls_stbl-col = 'X'. "基于列稳定刷新

  CALL FUNCTION 'GET_GLOBALS_FROM_SLVC_FULLSCR'
    IMPORTING
      e_grid = lr_grid.
  CALL METHOD lr_grid->check_changed_data.

  selfield-refresh = 'X'. "刷新数据
  CASE i_ucomm.
    WHEN '&IC1'.
      READ TABLE lt_item INTO ls_item INDEX selfield-tabindex.
      IF sy-subrc EQ 0.
        "IF ls_item-ebeln IS NOT INITIAL.
        "
        "  CALL FUNCTION 'ME_DISPLAY_PURCHASE_DOCUMENT'
        "    EXPORTING
        "      i_ebeln              = ls_item-ebeln
        "    EXCEPTIONS
        "      not_found            = 1
        "      no_authority         = 2
        "