当我们在自定义选择屏幕中， 需要写入我们自定义的搜索帮助的时候，可以通过预定义函数来实现：
实例说明：
第一步：创建搜索帮助SE11分销渠道(Z_VTWEG)
1.选择基本索引帮助：

2.选择参考表，因为这里分销渠道和文本来源于TVTWT，这里选择方法就填入TVTWT，对话类型选择D立即显示值，就是点击即可出现结果。

列表的意思是排列顺序
搜索帮助出口：需要我们自定义一个函数，可复制标准函数：F4IF_SHLP_EXIT_EXAMPLE去创建
参数和预定义函数一致，这里我们调用‘SELECT’这个时间点来进行数据的查询输出，自定义的帮助出口函数中的具体代码如下

FUNCTION zsd_vtweg_f4_exit.
*“----------------------------------------------------------------------
"“本地接口：
*” TABLES
*” SHLP_TAB TYPE SHLP_DESCT
*" RECORD_TAB STRUCTURE SEAHLPRES
*" CHANGING
*" VALUE(SHLP) TYPE SHLP_DESCR
*" VALUE(CALLCONTROL) LIKE DDSHF4CTRL STRUCTURE DDSHF4CTRL
*"----------------------------------------------------------------------
DATA:BEGIN OF lt_tab OCCURS 0,
vtweg TYPE vtweg,
vtext TYPE vtxtk,
spras TYPE spras,
END OF lt_tab.
DATA:r_vtweg TYPE RANGE OF vtweg WITH HEADER LINE,
r_vtext TYPE RANGE OF vtxtk WITH HEADER LINE,
r_spras TYPE RANGE OF spras WITH HEADER LINE,
ddshelops TYPE ddshselopt.

• EXIT immediately, if you do not want to handle this step
  IF callcontrol-step <> ‘SELONE’ AND
  callcontrol-step <> ‘SELECT’ AND
  " AND SO ON
  callcontrol-step <> ‘DISP’.
  EXIT.
  ENDIF.

*"----------------------------------------------------------------------

• STEP SELONE (Select one of the elementary searchhelps)
  *"----------------------------------------------------------------------
• This step is only called for collective searchhelps. It may be used
• to reduce the amount of elementary searchhelps given in SHLP_TAB.
• The compound searchhelp is given in SHLP.
• If you do not change CALLCONTROL-STEP, the next step is the
• dialog, to select one of the elementary searchhelps.
• If you want to skip this dialog, you have to return the selected
• elementary searchhelp in SHLP and to change CALLCONTROL-STEP to
• either to ‘PRESEL’ or to ‘SELECT’.
  IF callcontrol-step = ‘SELONE’.
• PERFORM SELONE …
  EXIT.
  ENDIF.

*"----------------------------------------------------------------------

• STEP PRESEL (Enter selection conditions)
  *"----------------------------------------------------------------------

• This step allows you, to influence the selection conditions either

• before they are displayed or in order to skip the dialog completely.

• If you want to skip the dialog, you should change CALLCONTROL-STEP

• to ‘SELECT’.

• Normaly only SHLP-SELOPT should be changed in this step.
  IF callcontrol-step = ‘PRESEL’.

• PERFORM PRESEL …
  LOOP AT record_tab INTO DATA(ls_table).

  ENDLOOP.
  EXIT.
  ENDIF.
  *"----------------------------------------------------------------------

• STEP SELECT (Select values)
  *"----------------------------------------------------------------------

• This step may be used to overtake the data selection completely.

• To skip the standard seletion, you should return ‘DISP’ as following

• step in CALLCONTROL-STEP.

• Normally RECORD_TAB should be filled after this step.

• Standard function module F4UT_RESULTS_MAP may be very helpfull in this

• step.
  IF callcontrol-step = ‘SELECT’.

• PERFORM STEP_SELECT TABLES RECORD_TAB SHLP_TAB

•                   CHANGING SHLP CALLCONTROL RC.
  

• IF RC = 0.

• CALLCONTROL-STEP = 'DISP'.
  

• ELSE.

• CALLCONTROL-STEP = 'EXIT'.
  

• ENDIF.
  "传入参数
  LOOP AT shlp-selopt INTO DATA(ls_selopt).
  CASE ls_selopt-shlpfield.
  WHEN ‘SPRAS’.
  MOVE-CORRESPONDING ls_selopt TO r_spras.
  APPEND r_spras.
  WHEN OTHERS.
  ENDCASE.
  ENDLOOP.
  "根据输入参数查询数据
  SELECT * INTO CORRESPONDING FIELDS OF TABLE lt_tab FROM tvtwt WHERE spras = sy-langu.
  "将查询结果回执到屏幕上来

    CALL FUNCTION 'F4UT_RESULTS_MAP'
*       EXPORTING
*         SOURCE_STRUCTURE         =
*         APPLY_RESTRICTIONS       = ' '
      TABLES
        shlp_tab          = shlp_tab
        record_tab        = record_tab
        source_tab        = lt_tab
      CHANGING
        shlp              = shlp
        callcontrol       = callcontrol
      EXCEPTIONS
        illegal_structure = 1
        OTHERS            = 2.
*下一个时间点直接转到DISP，否则无法再屏幕上显示帮助列表
    callcontrol-step = 'DISP'.
    EXIT. "Don't process STEP DISP additionally in this call.
  ENDIF.
*"----------------------------------------------------------------------
* STEP DISP     (Display values)
*"----------------------------------------------------------------------
* This step is called, before the selected data is displayed.
* You can e.g. modify or reduce the data in RECORD_TAB
* according to the users authority.
* If you want to get the standard display dialog afterwards, you
* should not change CALLCONTROL-STEP.
* If you want to overtake the dialog on you own, you must return
* the following values in CALLCONTROL-STEP:
* - "RETURN" if one line was selected. The selected line must be
*   the only record left in RECORD_TAB. The corresponding fields of
*   this line are entered into the screen.
* - "EXIT" if the values request should be aborted
* - "PRESEL" if you want to return to the selection dialog
* Standard function modules F4UT_PARAMETER_VALUE_GET and
* F4UT_PARAMETER_RESULTS_PUT may be very helpfull in this step.
  IF callcontrol-step = 'DISP'.
*   PERFORM AUTHORITY_CHECK TABLES RECORD_TAB SHLP_TAB
*                           CHANGING SHLP CALLCONTROL.
    LOOP AT record_tab INTO DATA(ls_item).

    ENDLOOP.
    EXIT.
  ENDIF.
ENDFUNCTION.

因为我这里是全部输出系统当前语言的分销渠道，所以这里的搜索没有去做限制，也可以更具具体情况去限制
3.自定义屏幕中写入参考我们的搜索帮助即可