abap对象的创建和调用。方法调用

1： abap中创建类和创建对象，调用方法。

*&---------------------------------------------------------------------*
*& Report ZHANSEN_T1
*&---------------------------------------------------------------------*
*&
*&---------------------------------------------------------------------*
REPORT ZHANSEN_T1.
CLASS application DEFINITION.  "定义类(相当于抽象类)
  PUBLIC SECTION.  "公有部分
    METHODS:show_text.
  PRIVATE SECTION.   "私有部分
    ) TYPE c VALUE 'this is my first abap object'.
ENDCLASS.

CLASS application IMPLEMENTATION. "实现类application。
  METHOD show_text.
    WRITE text.
  ENDMETHOD.
ENDCLASS.

DATA ob_app type ref to application.  "创建类的引用

*事件块。
START-OF-SELECTION.
  create object ob_app. "创建类对象。
  call METHOD ob_app->show_text.  "调用对象中的方法

2：创建方法和调用方法   https://blog.csdn.net/rztyzxzy/article/details/49562413

*&---------------------------------------------------------------------*
*& Report ZHANSEN_TEST25
*&---------------------------------------------------------------------*
*&
*&---------------------------------------------------------------------*
REPORT ZHANSEN_TEST25.
*----------------------------------------------------------------------*
*       CLASS callobj DEFINITION
*----------------------------------------------------------------------*
*       声明类
*----------------------------------------------------------------------*
CLASS callobj DEFINITION.
  PUBLIC SECTION.
    TYPES: BEGIN OF dt_city,
             name TYPE char10,
           END OF dt_city.
    TYPES: dt_it_city TYPE TABLE OF dt_city.
    DATA: ls_city TYPE dt_city.
    METHODS: meth1 IMPORTING value(ivt_city) TYPE dt_it_city. " 输入参数，內表作为参数
    METHODS: meth2 EXPORTING value(evs_city) TYPE dt_city.    " 输出参数，结构体作为参数
    METHODS: meth3 CHANGING  value(cv_num) TYPE i.

ENDCLASS.                    "callobj DEFINITION

*----------------------------------------------------------------------*
*       CLASS callobj IMPLEMENTATION
*----------------------------------------------------------------------*
*       实现类方法
*----------------------------------------------------------------------*
CLASS callobj IMPLEMENTATION.
  METHOD meth1.
    WRITE: '方法一：'.
    LOOP AT ivt_city INTO ls_city.
      WRITE: / ls_city-name.
    ENDLOOP.
  ENDMETHOD.                                                "meth1
  METHOD meth2.
    evs_city = '济南'.
  ENDMETHOD.                                                "meth2

  METHOD meth3.
    cv_num = cv_num + .
  ENDMETHOD.                                                "meth3
ENDCLASS.                    "callobj IMPLEMENTATION
DATA: obj TYPE REF TO callobj.
DATA: num TYPE i.
DATA: g_struc TYPE callobj=>dt_city. " 参考类变量定义相关结构体及内表
DATA: g_tab   TYPE callobj=>dt_it_city.

START-OF-SELECTION.
  CREATE OBJECT obj.
  g_struc-name = '北京'.
  APPEND g_struc TO g_tab.
  g_struc-name = '上海'.
  APPEND g_struc TO g_tab.
  g_struc-name = '广州'.
  APPEND g_struc TO g_tab.
  CALL METHOD: obj->meth1 EXPORTING ivt_city = g_tab,   " g_tab值赋给ivt_city
               obj->meth2 IMPORTING evs_city = g_struc. " evs_city值输出到g_struc
  WRITE:/ '方法二：',/ g_struc-name.
  WRITE:/ '方法三：'.
  WRITE: / num.
  CALL METHOD: obj->meth3 CHANGING cv_num = num.
  WRITE: / num.

3：调用方法，没有跑通

*&---------------------------------------------------------------------*
*& Report ZHANSEN_TEST26
*&---------------------------------------------------------------------*
*&
*&---------------------------------------------------------------------*
REPORT ZHANSEN_TEST26.
CLASS circle DEFINITION.    "定义类
  PUBLIC SECTION.
  METHODS get_ares
    IMPORTING VALUE(i_radius) TYPE i         "输入参数
    RETURNING VALUE(r_size) type f.          "返回数据
  PRIVATE SECTION.
  .
ENDCLASS.

CLASS circle IMPLEMENTATION.
  METHOD get_ares.
    r_size=i_radius.
  ENDMETHOD.
ENDCLASS.

PARAMETERS radius TYPE i.  "PARAMETERS定义的参数从屏幕中输入
DATA: o_circle TYPE REF TO circle,
      ares TYPE f.

START-OF-SELECTION.
  CREATE OBJECT o_circle.
  CALL METHOD o_circle->get_ares EXPORTING i_radius=radius RECEIVING r_size=ares.
  WRITE:/ ares.

4:直接在类中创建一个方法，可以直接执行。 例如下面的类zcl_class11

  method METHOD1.
    WRITE 'HELLO'.
  endmethod.

可以直接从另一个类中创建类对象，调用该类方法。

  method METHOD2.
    DATA lv_class11 type ref to zcl_myclass11.
    create object lv_class11.
    call method lv_class11->METHOD1.
  endmethod.