OO ALV 后台运行时错误：Control Framework: Fatal error - GUI cannot be reached

* ALV Grid
DATA: R_GRID TYPE REF TO CL_GUI_ALV_GRID.
DATA: R_CONTROL TYPE REF TO CL_GUI_CUSTOM_CONTAINER.
DATA: G_DOCK TYPE REF TO CL_GUI_DOCKING_CONTAINER.


MODULE STATUS_0100 OUTPUT.

  SET PF-STATUS ‘LISTOUT1‘.
  SET TITLEBAR ‘LIST1‘.

IF R_CONTROL IS INITIAL.
* Check whether the program is run in batch or foreground（判断是否后台运行）
    IF CL_GUI_ALV_GRID=>OFFLINE( ) IS INITIAL.
* Run in foreground
      CREATE OBJECT R_CONTROL EXPORTING CONTAINER_NAME = ‘CONTAINER_1‘.
      CREATE OBJECT R_GRID EXPORTING I_PARENT = R_CONTROL.
    ELSE.
* Run in background
      CREATE OBJECT R_GRID EXPORTING I_PARENT = G_DOCK.
    ENDIF.

* Structure ZBA_MARA1 is defined in DDIC as linetype
    CALL METHOD R_GRID->SET_TABLE_FOR_FIRST_DISPLAY
      EXPORTING
       I_STRUCTURE_NAME = ‘MARA‘
      CHANGING
       IT_OUTTAB = ITAB.
  ENDIF.

ENDMODULE. " STATUS_0100 OUTPUT