Can Selection Screen processing events be triggered manually?

Question

Good day!
I have a Selection Screen where a user can select a value from a drop-down box.  If a particular value is used, I assign default text to another Selection Screen field.
However, because choosing the drop-down value doesn't trigger a Selection Screen processing event (AT SELECTION-SCREEN and AT SELECTION-SCREEN OUTPUT) the value doesn't get updated on the screen field, even though it gets updated in memory.  It only updates on the screen if the user selects a radio button value for another field because that triggers the Selection Screen processing events.
I've read about various methods in an attempt to get this to work, but nothing is working.  Is there ANY way to trigger SAP to go to these events?
Thanks, and points for all helpful advice!
Dave

Answer 1

Hi dave,
1. Selecting a listbox on selection screen,
    and immediately populating a field value on the screen.
2. just copy paste to get a taste of it.
3.
REPORT ABC.
TYPE-POOLS : VRM.
DATA : VALUES TYPE VRM_VALUES.
DATA : VW LIKE LINE OF VALUES.
DATA : FLAG TYPE C.
PARAMETERS : LIST TYPE C AS LISTBOX VISIBLE LENGTH 10
<b>USER-COMMAND ABC.</b>
PARAMETERS : A(10) TYPE C.
INITIALIZATION.
  VW-KEY = '1'.
  VW-TEXT = 'SUN'.
  APPEND VW TO VALUES.
  VW-KEY = '2'.
  VW-TEXT = 'MON'.
  APPEND VW TO VALUES.
  VW-KEY = '3'.
  VW-TEXT = 'TUE'.
  APPEND VW TO VALUES.
  CALL FUNCTION 'VRM_SET_VALUES'
    EXPORTING
      ID              = 'LIST'
      VALUES          = VALUES
    EXCEPTIONS
      ID_ILLEGAL_NAME = 1
      OTHERS          = 2.
<b>AT SELECTION-SCREEN  OUTPUT.
A = LIST.</b>
regards,
amit m.