如何设置'REUSE_ALV_GRID_DISPLAY'的单个单元格的颜色

在ALV报表设计有时候需要根据一定条件将特定的单元显示成特定的颜色，具体实现步骤如下：

1. 在需要显示的内表中添加新的字段，字段类型为lvc_t_scol
2. 根据条件设置颜色数据；
3. 设置layout-coltab_fieldname的数据指定显示颜色的字段.
代码如下：（注意红色部分）
REPORT  z_alv_color.
TYPE-POOLS: slis.
DATA: BEGIN OF it_flight OCCURS 0,
       carrid  LIKE sflight-carrid,
       connid   LIKE sflight-connid,
       fldate   LIKE sflight-fldate,
       seatsmax LIKE sflight-seatsmax,
       seatsocc LIKE sflight-seatsocc,
       color TYPE lvc_t_scol,
      END OF it_flight.
DATA: it_fieldcat TYPE  slis_t_fieldcat_alv,
      layout TYPE  slis_layout_alv.
CALL FUNCTION 'REUSE_ALV_FIELDCATALOG_MERGE'
  EXPORTING
    i_program_name         = sy-repid
    i_internal_tabname     = 'IT_FLIGHT'
    i_inclname             = sy-repid
  CHANGING
    ct_fieldcat            = it_fieldcat
  EXCEPTIONS
    inconsistent_interface = 1
    program_error          = 2.

SELECT  carrid
       connid
       fldate
       seatsmax
       seatsocc
FROM sflight
INTO CORRESPONDING FIELDS OF TABLE it_flight
UP TO 20 ROWS.
DATA: col TYPE lvc_s_scol,
      coltab TYPE lvc_t_scol,
color TYPE lvc_s_colo.
color-col = '6'.
color-int = '0'.
color-inv = '0'.
LOOP AT it_flight.
  IF it_flight-seatsocc Eq 0.
    col-fname = 'SEATSOCC'.
    col-color = color.
    APPEND col TO coltab.
    CLEAR col.
    it_flight-color = coltab.
    MODIFY  it_flight.
 ENDIF.
ENDLOOP.
layout-coltab_fieldname = 'COLOR'.
CALL FUNCTION 'REUSE_ALV_GRID_DISPLAY'
  EXPORTING
    i_callback_program = sy-repid
    is_layout          = layout
    it_fieldcat        = it_fieldcat
  TABLES
    t_outtab           = it_flight
  EXCEPTIONS
    program_error      = 1.