How to Create a DropDown Box in a Selection Screen.

Question

Hi,
I have a question. i.e, How to create a dropdown box in a Selection Screen. Could you please assist me.
Thanks & Regards
Sathish Kumar

Answer 1

hi satish,
The following can assist u to create a drop down ....
Drop down list box can be created in a dialog screen(SE51) as well as selection screen.
  The sap list box allows to select a value from the list but we cannot enter our own value in the list box .The value list that will be displayed consists of two
fields TEXT field of TYPE 80(C) and internal KEY field of TYPE 40(C).
In screen painter to create a input/output field into list box we use
'L" as a value for dropdown attribute for the i/o field.
In screen painter to determine the type of method that will be used to fill the value
list we use the attribute value list.
If it is blank  the value list will be filled by the first column of the input help assigned to the screen field.This input help can be defined in the ABAP Dictionary, on screen using SELECT,VALUES screen statements or in event POV (PROCESS ON VALUE-REQUEST ) and the input help that will be passed to the field should consists of 2 columns ,the key column is filled automatically by the system.SAP recommends value list field should be blank.
or
The value  can be 'A' meaning that the value list will be filled in the event PBO(PROCESS BEFORE OUTPUT) or before the screen is displayed.In this method we use function module VRM_SET_VALUES to fill the values and pass it to the i/o field.
If a function code is attached to the list box the selection of a value triggers a PAI
otherwise PAI will not trigger.
Example
Dropdown list boxes
REPORT DEMO_DYNPRO_DROPDOWN_LISTBOX.
TYPE-POOLS VRM.
DATA: NAME  TYPE VRM_ID,
      LIST  TYPE VRM_VALUES,
      VALUE LIKE LINE OF LIST.
DATA: WA_SPFLI TYPE SPFLI,
      OK_CODE LIKE SY-UCOMM,
      SAVE_OK LIKE SY-UCOMM.
TABLES DEMOF4HELP.
NAME = 'DEMOF4HELP-CONNID'.
CALL SCREEN 100.
MODULE CANCEL INPUT.
  LEAVE PROGRAM.
ENDMODULE.
MODULE INIT_LISTBOX OUTPUT.
  CLEAR DEMOF4HELP-CONNID.
  SELECT  CONNID CITYFROM CITYTO DEPTIME
    FROM  SPFLI
    INTO  CORRESPONDING FIELDS OF WA_SPFLI
   WHERE  CARRID = DEMOF4HELP-CARRIER2.
    VALUE-KEY  = WA_SPFLI-CONNID.
    WRITE WA_SPFLI-DEPTIME TO VALUE-TEXT
                           USING EDIT MASK '__:__:__'.
    CONCATENATE VALUE-TEXT
                WA_SPFLI-CITYFROM
                WA_SPFLI-CITYTO
                INTO VALUE-TEXT SEPARATED BY SPACE.
    APPEND VALUE TO LIST.
  ENDSELECT.
  CALL FUNCTION 'VRM_SET_VALUES'
       EXPORTING
            ID              = NAME
            VALUES          = LIST.
ENDMODULE.
MODULE USER_COMMAND_100.
  SAVE_OK = OK_CODE.
  CLEAR OK_CODE.
  IF SAVE_OK = 'CARRIER'
     AND NOT DEMOF4HELP-CARRIER2 IS INITIAL.
    LEAVE TO SCREEN 200.
  ELSE.
    SET SCREEN 100.
  ENDIF.
ENDMODULE.
MODULE USER_COMMAND_200.
  SAVE_OK = OK_CODE.
  CLEAR OK_CODE.
  IF SAVE_OK = 'SELECTED'.
    MESSAGE I888(BCTRAIN) WITH TEXT-001 DEMOF4HELP-CARRIER2
                                        DEMOF4HELP-CONNID.
  ENDIF.
ENDMODULE.
Reward if useful.
Thank you,
Regards.