[Sample code]CL_ALV_TABLE_CREATE=>CREATE_DYNAMIC_TABLE

REPORT  ZTEST_DYNAMIC_ALV.

TYPE-POOLS: SLIS.

FIELD-SYMBOLS:  TYPE STANDARD TABLE,
               .

DATA: ALV_FLDCAT TYPE SLIS_T_FIELDCAT_ALV,
      IT_FLDCAT TYPE LVC_T_FCAT.

SELECTION-SCREEN BEGIN OF BLOCK B1 WITH FRAME TITLE TEXT-001.
PARAMETERS: P_FLDS(5) TYPE C.
SELECTION-SCREEN END OF BLOCK B1.

START-OF-SELECTION.

* build the dynamic internal table
  PERFORM BUILD_DYN_ITAB.

* write 5 records to the alv grid
  DO 5 TIMES.
    PERFORM BUILD_REPORT.
  ENDDO.

* call the alv grid.
  PERFORM CALL_ALV.


************************************************************************
*  Build_dyn_itab
************************************************************************
FORM BUILD_DYN_ITAB.

  DATA: NEW_TABLE TYPE REF TO DATA,
        NEW_LINE  TYPE REF TO DATA,
        WA_IT_FLDCAT TYPE LVC_S_FCAT.

* Create fields .
  DO P_FLDS TIMES.
    CLEAR WA_IT_FLDCAT.
    WA_IT_FLDCAT-FIELDNAME = SY-INDEX.
    WA_IT_FLDCAT-DATATYPE = 'CHAR'.
    WA_IT_FLDCAT-INTLEN = 5.
    APPEND WA_IT_FLDCAT TO IT_FLDCAT .
  ENDDO.

* Create dynamic internal table and assign to FS
  CALL METHOD CL_ALV_TABLE_CREATE=>CREATE_DYNAMIC_TABLE
    EXPORTING
      IT_FIELDCATALOG = IT_FLDCAT
    IMPORTING
      EP_TABLE        = NEW_TABLE.

  ASSIGN NEW_TABLE->* TO .

* Create dynamic work area and assign to FS
  CREATE DATA NEW_LINE LIKE LINE OF .
  ASSIGN NEW_LINE->* TO .

ENDFORM.                    "build_dyn_itab

*********************************************************************
*      Form  build_report
*********************************************************************
FORM BUILD_REPORT.

  DATA: FIELDNAME(20) TYPE C.
  DATA: FIELDVALUE(5) TYPE C.
  DATA: INDEX(3) TYPE C.
  FIELD-SYMBOLS: .

  DO P_FLDS TIMES.

    INDEX = SY-INDEX.

* Set up fieldvalue
    CONCATENATE 'FLD' INDEX INTO
             FIELDVALUE.
    CONDENSE   FIELDVALUE NO-GAPS.

    ASSIGN COMPONENT  INDEX  OF STRUCTURE  TO .
     =  FIELDVALUE.

  ENDDO.

* Append to the dynamic internal table
  APPEND  TO .


ENDFORM.                    "build_report

************************************************************************
*  CALL_ALV
************************************************************************
FORM CALL_ALV.

  DATA: WA_CAT LIKE LINE OF ALV_FLDCAT.

  DO P_FLDS TIMES.
    CLEAR WA_CAT.
    WA_CAT-FIELDNAME = SY-INDEX.
    WA_CAT-SELTEXT_S = SY-INDEX.
    WA_CAT-OUTPUTLEN = '5'.
    APPEND WA_CAT TO ALV_FLDCAT.
  ENDDO.


* Call ABAP List Viewer (ALV)
  CALL FUNCTION 'REUSE_ALV_GRID_DISPLAY'
    EXPORTING
      IT_FIELDCAT = ALV_FLDCAT
    TABLES
      T_OUTTAB    = .

ENDFORM.                    "call_alv