abap - 在不使用 TABLES 关键字的情况下修改输入字段上的文本

Question

我想在屏幕的输入字段上显示文本，这是工作区的值，分别是名称、年龄和城市，如您所见。当我声明 znew_fdkey01和 znew_fdkey02 (这是透明表)使用 TABLES像这样的关键字:

TABLES: znew_fdkey01, znew_fdkey02.

它完美地工作。但是当我想在不使用此关键字的情况下获得相同的效果时，并且当我像这样声明变量时:

DATA: znew_fdkey01 TYPE znew_fdkey01,
      znew_fdkey02 TYPE znew_fdkey02.

它不会在输入字段中显示文本。
为什么？
注意:这是初始化屏幕字段的代码(两种情况相同):

LOOP AT SCREEN INTO screen_wa.

  IF screen_wa-name = 'ZNEW_FDKEY01-NAME'.
    znew_fdkey01-name = lr_znewfdkey3-name.
  ENDIF.

  IF screen_wa-name = 'ZNEW_FDKEY01-AGE'.
    znew_fdkey01-age = lr_znewfdkey3-age.
  ENDIF.

  IF screen_wa-name = 'ZNEW_FDKEY02-CITY'.
    znew_fdkey02-city = lr_znewfdkey3-city.
  ENDIF.

  MODIFY SCREEN FROM screen_wa.

ENDLOOP.

Answer 1

这是正确的，TABLES 定义了工作区域，同时需要确保屏幕(dynpro)和 ABAP 程序之间的自动通信，如 ABAP Help 中所述。 :

Table work areas declared using TABLES are interface work areas...

The statement TABLES is required for exchanging data between dynpro fields and the ABAP program, if the fields were defined in a dynpro in the program by being taken from ABAP Dictionary, . In the dynpro event PBO, the content of the table work area is passed to identically named dynpro fields. In PAI, the system takes the data from identically named dynpro fields.

(否则不要使用 TABLES 来声明工作区，这是过时的)