How to add Dropdown functionality in the ALV report

REPORT Example.
*Data Declaration
TYPES: BEGIN OF ty_ekko,
      ebeln TYPE ebeln,
      bukrs TYPE bukrs,
      ekorg TYPE ekorg,
      END OF ty_ekko.
 DATA : gt_ekko TYPE TABLE OF ty_ekko,
        gs_ekko TYPE ty_ekko.
*Custom Container
 DATA: r_container TYPE REF TO cl_gui_custom_container,
      r_grid      TYPE REF TO cl_gui_alv_grid.
*table for the dropdown data
  DATA: it_dropdown TYPE lvc_t_drop,
        ty_dropdown TYPE lvc_s_drop.
*Catalog/layout
DATA: gt_fieldcat  TYPE  lvc_t_fcat ,
      gs_fieldcat type lvc_s_fcat,
      gs_layout    TYPE lvc_s_layo,
      OK_CODE     TYPE SY-UCOMM.

START-OF-SELECTION.
CALL SCREEN 100.
MODULE status_0100 OUTPUT.
set PF-STATUS 'ZMV'.
PERFORM retrieve_data.
PERFORM create_catalog.
*Container definitions
 CREATE OBJECT r_container
  EXPORTING
  container_name    = 'CUST'.
 CREATE OBJECT r_grid
   EXPORTING
     i_parent          = r_container.
CALL METHOD r_grid->set_drop_down_table
   EXPORTING
      it_drop_down = it_dropdown.
CALL METHOD r_grid->set_table_for_first_display
  CHANGING
    it_outtab                     = gt_ekko
    it_fieldcatalog               = gt_fieldcat
  EXCEPTIONS
    invalid_parameter_combination = 1
    program_error                 = 2
    too_many_lines                = 3
    others                        = 4.
ENDMODULE.                 " STATUS_0100  OUTPUT

FORM retrieve_data.
select ebeln bukrs ekorg from ekko into table gt_ekko up to 20 rows.
ENDFORM.

FORM create_catalog.
  gs_fieldcat-fieldname  = 'EBELN'.
  gs_fieldcat-coltext = 'EBELN'.
  APPEND gs_fieldcat to gt_fieldcat.
  clear: gs_fieldcat.
   gs_fieldcat-fieldname  = 'BUKRS'.
  gs_fieldcat-coltext = 'BUKRS'.
  gs_fieldcat-edit = 'X'.
  gs_fieldcat-drdn_hndl = '2'.
  APPEND gs_fieldcat to gt_fieldcat.
  clear: gs_fieldcat.
  gs_fieldcat-fieldname  = 'EKORG'.
  gs_fieldcat-coltext = 'EKORG'.
  APPEND gs_fieldcat to gt_fieldcat.
    clear: gs_fieldcat.

PERFORM fill_dropdown.
ENDFORM.                    " CREATE_CATALOG
FORM fill_dropdown.
   ty_dropdown-handle = '2'.
   ty_dropdown-value = 'Yes'.
   APPEND ty_dropdown TO it_dropdown.
   ty_dropdown-handle = '2'.
   ty_dropdown-value = 'No'.
   APPEND ty_dropdown TO it_dropdown.

ENDFORM.   
MODULE user_command_0100 INPUT.
CASE OK_CODE.
  WHEN 'EXIT' OR 'BACK'.
    LEAVE PROGRAM.
ENDCASE. 
ENDMODULE.                 " USER_COMMAND_0100  INPUT
                 " FILL_DROPDOWN

Here in the above code, we are displaying ALV using the custom container.

To use a custom container with CL_GUI_ALV_GRID, you’ll need to work with a screen in your SAP program. This screen will serve as the area where your custom container will appear. Insert a custom control element on the screen and assign it a name, like 'CUST'. Then initiate the objects.

In setting the field catalog, set the column where the drop down list will appear. Set the parameter drdn_hndl which is included in the structure LVC_S_FCAT. So if your ALV grid will display four(4) columns and you want to display the drop down list on the second column, the value of the parameter would be drdn_hndl = 2.

We have the lvc_t_drop table. Fill in the values for the drop-down using this table, which contains two fields: handle and value**.** The handle will be 2 in our case because we are adding the dropdown for the second column. The value will be whatever you want to give.

We have the set_drop_down_table method of class cl_gui_alv_grid to set the dropdown for the column.

Then using the set_table_for_first_display method we are displaying the ALV.