为选择屏幕的字段设置F4帮助

在没有参考 数据元素，域和搜索帮助的情况下，自定义F4 帮助

1，PARAMETERS: p_bukrs(4) TYPE C MATCHCODE OBJECT H_T001.

2，AT SELECTION-SCREEN  ON VALUE-REQUEST  FOR  p_bukrs.

        PERFORM frm_f4 CHANGING p_bukrs.

FORM frm_f4 CHANGING p_value.

   CONSTANTS cns_retfield TYPE fieldname VALUE 'BUKRS'.   

   DATA: BEGIN OF lt_value OCCURS 0,
            bukrs LIKE t001-bukrs, "公司代码     

            butxt LIKE t001-butxt, " 公司名称      

            END OF lt_value. 
   DATA: lt_retuen LIKE TABLE OF  ddshretval WITH HEADER LINE.  

  SELECT bukrs butxt FROM t001 INTO TABLE lt_value.    

CALL FUNCTION 'F4IF_INT_TABLE_VALUE_REQUEST' 

    EXPORTING
        retfield        = cns_retfield  

        value_org       = 'S'   

   TABLES
       value_tab       = lt_value     

      return_tab      = lt_retuen   

   EXCEPTIONS
       parameter_error = 1     

   no_values_found = 2      

  OTHERS          = 3.  

  IF sy-subrc = 0.
    READ TABLE lt_retuen  INDEX 1.    

    p_value  = lt_retuen-fieldval. 

  ELSE.

  ENDIF.
ENDFORM.                    "frm_f4_bukrs