ABAP CALL TRANSACTION and fill variant field - abap

Question

I used this bit of code the exact same way in a previous program and it worked. Now I am using it to apply to a transaction with a range available for the field I want to fill with the information clicked on the hotspot. It is not placing anything in the field when taken to ME2N view. Any suggestions?
FORM user_command USING r_ucomm LIKE sy-ucomm
rs_selfield TYPE slis_selfield.
CASE r_ucomm.
WHEN '&IC1'.
IF rs_selfield-fieldname = 'EBELN'.
READ TABLE itab_usr INTO wa_usr INDEX rs_selfield-tabindex.
SET PARAMETER ID 'BES' FIELD wa_usr-ebeln.
CALL TRANSACTION 'ME2N'.
ENDIF.
ENDCASE.
ENDFORM.

Answer 1

What you're doing is basically writing something on the wall and then nudging the next person. It's up to the next person to decide whether they want to read whatever's written on the wall. The parameters area is just a global memory - perhaps the called program will do something about it, but unless it states so in its documentation, you can't rely on that.
In the case of ME2N, you may want to examine the transaction and find out that it simply calls the selection screen of a report, let's say RM06EN00. You may then want to look up the keyword SUBMIT and the relevant documentation about filling the selection screen of a called program.

Answer 2

You can find more information from here.
DATA : WA_FCAT TYPE LVC_S_FCAT,
IT_FCAT TYPE STANDARD TABLE OF LVC_S_FCAT,
OB_CUSTOM_CONTAINER TYPE REF TO CL_GUI_CUSTOM_CONTAINER,
OB_GRID TYPE REF TO CL_GUI_ALV_GRID,
G_VARIANT LIKE DISVARIANT,
LT_DEMO_DATA TYPE TABLE OF ZDEMO_TABLE.
INITIALIZATION.
START-OF-SELECTION.
" GET DATA .
REFRESH LT_DEMO_DATA.
SELECT * INTO TABLE LT_DEMO_DATA FROM ZDEMO_TABLE.
PERFORM FIELDCAT.
CALL SCREEN 1001.
CLASS LCL_EVENT_HANDLER DEFINITION.
PUBLIC SECTION.
METHODS HANDLE_HOTSPOT_CLICK FOR EVENT HOTSPOT_CLICK OF CL_GUI_ALV_GRID
IMPORTING E_ROW_ID E_COLUMN_ID ES_ROW_NO.
ENDCLASS.
CLASS LCL_EVENT_HANDLER IMPLEMENTATION.
METHOD HANDLE_HOTSPOT_CLICK .
PERFORM HOTSPOT_CLICK USING E_ROW_ID E_COLUMN_ID.
ENDMETHOD.
ENDCLASS.
FORM HOTSPOT_CLICK USING E_ROW TYPE LVC_S_ROW E_COLUMN_ID TYPE LVC_S_COL.
DATA : WA_DEMO TYPE ZDEMO_TABLE.
READ TABLE LT_DEMO_DATA INTO WA_DEMO INDEX E_ROW-INDEX.
SET PARAMETER ID 'MAT' FIELD WA_DEMO-MATNR.
CALL TRANSACTION 'MB51'.
ENDFORM.
*&---------------------------------------------------------------------*
*& Module STATUS_1001 OUTPUT
*&---------------------------------------------------------------------*
MODULE STATUS_1001 OUTPUT.
SET PF-STATUS 'STANDARD_FULLSCREEN'.
SET TITLEBAR 'TITLE'.
IF G_VARIANT IS INITIAL.
G_VARIANT-REPORT = SY-REPID.
G_VARIANT-USERNAME = SY-UNAME.
ENDIF.
"Object creation for custom container exporting the name
CREATE OBJECT OB_CUSTOM_CONTAINER
EXPORTING
CONTAINER_NAME = 'ALV_GRID'.
CREATE OBJECT OB_GRID
EXPORTING
I_PARENT = OB_CUSTOM_CONTAINER.
CALL METHOD OB_GRID->SET_TABLE_FOR_FIRST_DISPLAY
EXPORTING
IS_VARIANT = G_VARIANT
I_DEFAULT = 'X'
I_SAVE = 'A'
CHANGING
IT_FIELDCATALOG = IT_FCAT
IT_OUTTAB = LT_DEMO_DATA.
**** For Hotspot Event Handling
DATA: G_HANDLER TYPE REF TO LCL_EVENT_HANDLER.
CREATE OBJECT G_HANDLER.
SET HANDLER G_HANDLER->HANDLE_HOTSPOT_CLICK FOR OB_GRID.
ENDMODULE.
*&---------------------------------------------------------------------*
*& Form FIELDCAT
*&---------------------------------------------------------------------*
ENDFORM.
*&---------------------------------------------------------------------*
*& Module USER_COMMAND_1001 INPUT
*&---------------------------------------------------------------------*
MODULE USER_COMMAND_1001 INPUT.
IF SY-UCOMM = '&F03' OR SY-UCOMM = '&F12' OR SY-UCOMM = '&F15'.
FREE: OB_GRID.
REFRESH: LT_DEMO_DATA.
LEAVE TO SCREEN 0.
ENDIF.
ENDMODULE.