ABAP TBL隐藏列

如何隐藏某列
隐藏屏幕字段，我们首先想到的肯定是LOOP AT SCREEN，设置ACTIVE或INVISIBLE的字段值。可惜测试后，发现行不通。正确的做法是，通过编程修改tabctrl-cols下的某字段可见长度。

DATA: l_hide TYPE c,
      ls_col LIKE LINE OF tc_0100-cols.
LOOP AT tc_0100-cols INTO ls_col WHERE screen-name = 'WA-FIELD2'.
  IF l_hide IS INITIAL.
    ls_col-vislength = 6.
  ELSE.
    ls_col-vislength = 0.
  ENDIF.
  MODIFY tc_0100-cols FROM ls_col.
ENDLOOP.