自定义增强字段

正常情况下通过FM Exits来增强一个屏幕的步骤：

  1. Find relevant enhancement thru program name.

  2. T-code: CMOD, create an enhancement project, then assign the enhancement to the enhancement project

  3. Create a subscreen in corresponding X function group

  4. Implement the FM exits for transporting data to subscreen and retrieving data from subscreen.

  5. Active the enhancement project.

在main screen的flow logic中

  • PBO

    CALL CUSTOMER-SUBSCREEN <area> INCLUDING <x-function-pool> <screen_number>.
  "Transporting data to subscreen"
  MODULE ...
    CALL CUSTOMER-FUNCTION 'xxx'
      EXPORTING
        i_vars = gl_field.

  • PAI

    CALL CUSTOMER-SUBSCREEN <area> .
  "Transporting data from subscreen"
  MODULE...
     CALL CUSTOMER-FUNCTION 'xxx'
       IMPORTING
          o_vars = gl_field.

    这里的FM 的parameter interface是不能改变的，且每一个screen enhancemnet都要对应一个确定的自定义的 XXX Function Group但screen number是可以变化的。