ABAP 选择屏幕上的自定义搜索帮助

1.搜索帮助调用处

AT SELECTION-SCREEN ON VALUE-REQUEST FOR S_ZPUR-LOW.
PERFORM frm_f4_zpur.

2.搜索帮助方法明细

FORM FRM_F4_ZPUR .
DATA:LT_ZMMT407 TYPE TABLE OF ZMMT407.

   SELECT
     *
     FROM ZMMT407
     INTO CORRESPONDING FIELDS OF  TABLE @LT_ZMMT407.
  SORT LT_ZMMT407 BY ZPURSORT.
  DELETE ADJACENT DUPLICATES FROM LT_ZMMT407 COMPARING ZPURSORT.

*将取到的值通过函数显示在搜索帮助显示框中
CALL FUNCTION 'F4IF_INT_TABLE_VALUE_REQUEST'
   EXPORTING
*    DDIC_STRUCTURE         = ' '
     RETFIELD               = 'ZPURSORT'            "这个参数为帮助表中返回到选择屏幕的字段的参数
*    PVALKEY                = ' '
     DYNPPROG               = SY-REPID           "当前程序，不写会有问题
     DYNPNR                 = SY-DYNNR           "当前屏幕，不写会有问题
     DYNPROFIELD            = 'S_ZPUR-LOW'       "选择屏幕上需要加F4帮助的字段
*    STEPL                  = 0
*    WINDOW_TITLE           =
*    VALUE                  = ' '
     VALUE_ORG              = 'S'                "默认为C但是此处不用S不行
*    MULTIPLE_CHOICE        = ' '
*    DISPLAY                = ' '
*    CALLBACK_PROGRAM       = ' '
*    CALLBACK_FORM          = ' '
*    CALLBACK_METHOD        =
*    MARK_TAB               =
*  IMPORTING
*    USER_RESET             =
   TABLES
     VALUE_TAB              = LT_ZMMT407           "F4帮助值的表
*    FIELD_TAB              =
*    RETURN_TAB             =
*    DYNPFLD_MAPPING        =
  EXCEPTIONS
    PARAMETER_ERROR        = 1
    NO_VALUES_FOUND        = 2
    OTHERS                 = 3
           .
IF SY-SUBRC <> 0.
*Implement suitable error handling here
ENDIF.
ENDFORM.