10/08

[nangnangchuai]

定义类声明对象

REPORT  ZTEST_LTT4_TEST.

*类的定义
class c1 DEFINITION.

  PUBLIC SECTION.
  METHODS meth.
  ENDCLASS.

*  类的实现
  class c1 IMPLEMENTATION.
    METHOD meth.
     WRITE : /'CLASS TEST'.
     ENDMETHOD.
    ENDCLASS.

DATA: go_cref type REF TO c1.  "实例变量
START-OF-SELECTION.
create OBJECT go_cref.
call METHOD go_cref->meth.

[nangnangchuai]

方法的传参，

其中定义时候的importing代表传入的参数，当调用方法的时候用exporting去接参数

公开方法传参数

class c1 DEFINITION.
PUBLIC SECTION.
DATA:I_char type char20.
METHODS:set_data IMPORTING p_imp TYPE char20, "传入参数
get_data EXPORTING p_exp TYPE char20. "传出参数

ENDCLASS.

CLASS c1 IMPLEMENTATION. METHOD set_data. I_char = p_imp. ENDMETHOD.

METHOD get_data.
  p_exp = I_char.
ENDMETHOD.
ENDCLASS.

DATA:go_cref TYPE REF TO c1. DATA:gv_data TYPE char20.

START-OF-SELECTION. CREATE OBJECT go_cref. call METHOD : go_cref->set_data EXPORTING p_imp = 'test class method'. "I_CHAR=test class method

call METHOD: go_cref->get_data IMPORTING p_exp = gv_data. "将gv_data作为p_exp传进去，使得I_char的值赋值给了gv_data write gv_data. "输出gv_data的结果为test class method

[nangnangchuai]

PROTECTED SECTION. "只有继承的类才可以访问"类继承

CLASS c1 DEFINITION.
  PROTECTED SECTION. "只有继承的类才可以访问
  DATA:i_num TYPE i.
ENDCLASS. 
CLASS c2 DEFINITION INHERITING FROM c1.   "类继承
  PUBLIC SECTION.
    METHODS: set_data IMPORTING p_imp TYPE i,
             get_data EXPORTING p_exp TYPE i.
ENDCLASS.                    "c2 DEFINITION
CLASS c2 IMPLEMENTATION.
  METHOD set_data.
    i_num = p_imp.
  ENDMETHOD.                    "set_data
  METHOD get_data.
    p_exp = i_num + 1.
  ENDMETHOD.                    "get_data
ENDCLASS.                    "c2 IMPLEMENTATION
DATA:go_cref TYPE REF TO c2.
DATA:gv_data TYPE i.

START-OF-SELECTION.
  CREATE OBJECT go_cref.     "创建对象
  CALL METHOD : go_cref->set_data
                EXPORTING p_imp = '10'.   "这里exporting代表传入参数

  CALL METHOD: go_cref->get_data
               IMPORTING p_exp = gv_data.             "将gv_data作为p_exp传进去，importing代表传出的参 数
  WRITE gv_data.                                      "输出gv_data的结果为11

[nangnangchuai]

使用等号可以用来赋值，创建对象

class cls DEFINITION INHERITING FROM OBJECT.
  PUBLIC SECTION.
  METHODs:create.
  ENDCLASS.

  class cls IMPLEMENTATION.
    METHOD create.
      write : / '对象被创建了'.
    ENDMETHOD.
    ENDCLASS.

 DATA:go_obj1 type REF TO cls.
 DATA:go_obj2 type REF TO cls.

START-OF-SELECTION.
 CREATE OBJECT go_obj1.
 go_obj2 = go_obj1.  "使用=创建了对象
 CALL METHOD: go_obj2->create.

[nangnangchuai]

类型的转换

class vehicle DEFINITION INHERITING FROM object.
  PUBLIC SECTION.
   METHODs:create,          "公开的方法
           drive.
   PROTECTED SECTION.      "私有的变量
    DATA speed TYPE i VALUE '100'.
ENDCLASS.

   CLASS plane DEFINITION INHERITING FROM vehicle.
     PUBLIC SECTION.         "飞机有飞的方法继承vehicle类
     METHODs:fly.
     ENDCLASS.

  class vehicle IMPLEMENTATION.
    METHOD create.
      ENDMETHOD.
    METHOD drive.
      speed = speed + 100.
      WRITE : /'当前的速度为', speed.
      ENDMETHOD.
    ENDCLASS.

    CLASS plane IMPLEMENTATION.
      METHOD fly.
         speed = speed + 1000. "f飞机类自己的方法的实现
        ENDMETHOD.
      ENDCLASS.

data: car TYPE REF TO vehicle,
      air TYPE REF TO vehicle.

     START-OF-SELECTION.
      CREATE OBJECT car.
      air ?= car.
      CALL METHOD air->drive.  "输出200

[nangnangchuai]

动态调用方法

    CLASS c5 DEFINITION.
      PUBLIC SECTION.
        DATA: gt_itab TYPE TABLE OF sflight,
              gs_str TYPE sflight.
        METHODS: get_data,
                 wri_data.
    ENDCLASS.                    "c5 DEFINITION

    CLASS c5 IMPLEMENTATION.
      METHOD: get_data.
        SELECT * INTO TABLE gt_itab
          FROM sflight
          UP TO 5 ROWS.
      ENDMETHOD.
      METHOD: wri_data.
        LOOP AT gt_itab INTO gs_str.
          WRITE:/ gs_str-carrid,gs_str-connid.
        ENDLOOP.
        ENDMETHOD.                 "get_data
    ENDCLASS.                    ".
    DATA: go_oref TYPE REF TO c5.
    DATA: gv_mth TYPE string.
    START-OF-SELECTION.
      CREATE OBJECT go_oref.
      gv_mth = 'GET_DATA'.
      call METHOD go_oref->(gv_mth).   "动态调用方法名称为get_data的方法
      gv_mth = 'WRI_DATA'.              
      call METHOD go_oref->(gv_mth).  "动态调用方法名册名称为wri_data的方法

[nangnangchuai]

有关指针的不太懂

CLASS c5 IMPLEMENTATION.
  METHOD: get_data.
    SELECT * INTO TABLE gt_itab
      FROM sflight
      UP TO 5 ROWS.
  ENDMETHOD.                 "get_data
ENDCLASS.                    ".
DATA: go_oref TYPE REF TO c5.
DATA: gv_mth TYPE string.
DATA:gv_attr TYPE string.

FIELD-SYMBOLS: <fs1> TYPE STANDARD TABLE .
FIELD-SYMBOLS: <fs2> TYPE any  .
FIELD-SYMBOLS: <fs3> TYPE any  .

START-OF-SELECTION.
  CREATE OBJECT go_oref.
  gv_mth = 'GET_DATA'.
  CALL METHOD go_oref->(gv_mth).
  gv_attr = 'gt_itab'.
  ASSIGN go_oref->(gv_attr) TO <fs1>.

  LOOP AT <fs1> ASSIGNING <fs2>.
    DO.
      ASSIGN COMPONENT sy-index OF STRUCTURE <fs2> TO <fs3>.
      WRITE:  <fs3>.
      IF sy-subrc NE 0.
        EXIT.
      ENDIF.
    ENDDO.

    WRITE: /.
  ENDLOOP.

[nangnangchuai]

构造方法传入参数的使用

CLASS c1 DEFINITION.
  PUBLIC SECTION.
    DATA:gt_itab TYPE TABLE OF sflight,
         gs_str  TYPE sflight.
    DATA:gv_carrid TYPE s_carr_id,
         gv_connid TYPE s_conn_id.
    METHODS:constructor IMPORTING i_carrid TYPE s_carr_id  "构造方法的定义
                                  i_connid TYPE s_conn_id.
    METHODS:get_data.                                      "定义取数的方法

ENDCLASS.                    "c1 DEFINITION

*----------------------------------------------------------------------*
*       CLASS c1 IMPLEMENTATION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS c1 IMPLEMENTATION.
  METHOD:constructor.                                 "构造方法的实现
    gv_carrid =  i_carrid.
    gv_connid =  i_connid.
  ENDMETHOD.                    "CONSTRUCTOR

  METHOD get_data.                                     "实现取数的方法
    SELECT * INTO TABLE gt_itab
      FROM sflight
      WHERE carrid = gv_carrid
      AND   connid = gv_connid.
  ENDMETHOD.                    "get_data

ENDCLASS.                    "c1 IMPLEMENTATION

DATA go_oref TYPE REF TO c1. "声明类的对象

START-OF-SELECTION.           "必须写，否则后面的代码无法访问的到
  CREATE OBJECT go_oref     "创建对象，构造函数需要的值进行传参
         EXPORTING
           i_carrid = 'AA'
           i_connid = '0017'.
  CALL METHOD go_oref->get_data. "静态方法调用，调用get_data方法。

  LOOP AT go_oref->gt_itab INTO go_oref->gs_str.  "遍历对象中表的值到工作区
    write: / go_oref->gs_str-carrid,
             go_oref->gs_str-connid,
             go_oref->gs_str-fldate.

  ENDLOOP.

[nangnangchuai]

在子类中重写父类的方法和调用父类的方法

clASS CLS1 DEFINITION INHERITING FROM OBJECT.
  PUBLIC SECTION.
    METHODS:create.
  ENDCLASS.

  CLASS CLS1 IMPLEMENTATION.
    METHOD create.
      WRITE:/ '我是父类的构造方法'.
    ENDMETHOD.

  ENDCLASS.

  CLASS CLS2 DEFINITION INHERITING FROM CLS1.
    PUBLIC SECTION.
    METHODS:create REDEFINITION. "重定义create方法
  ENDCLASS.

  CLASS CLS2 IMPLEMENTATION.
    METHOD create.
      CALL METHOD super->create.
      WRITE:'调用父类的create方法'.
    ENDMETHOD.
  ENDCLASS.

  DATA:go_obj TYPE REF TO cls2.

  start-of-SELECTION.
   create OBJECT :go_obj.
   CALL METHOD:go_obj->create.

[nangnangchuai]

event事件的定义

CLASS c1 DEFINITION.
  PUBLIC SECTION.
    EVENTS:bowl.
    METHODs go_bowl. "声明事件
  ENDCLASS.                    "c1 DEFINITION

*----------------------------------------------------------------------*
*       CLASS C2 DEFINITION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS c2 DEFINITION.
  PUBLIC SECTION.
    METHODS letsgo FOR EVENT bowl OF c1. "声明事件处理器的方法为c1类定义的事件做处理
ENDCLASS.                    "C2 DEFINITION
*----------------------------------------------------------------------*
*       CLASS C1 IMPLEMENTATION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS c1 IMPLEMENTATION.
  METHOD go_bowl.
    WRITE'稍等'.
    RAISE EVENT bowl.  "触发事件
  ENDMETHOD.                    "go_bowl

ENDCLASS.                    "C1 IMPLEMENTATION

*----------------------------------------------------------------------*
*       CLASS C2 IMPLEMENTATION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS c2 IMPLEMENTATION.
  METHOD letsgo.
    WRITE'收到马上出发'.
  ENDMETHOD.
  ENDCLASS.                    "C2 IMPLEMENTATION

  DATA :kim TYPE REF TO c1,
        lee TYPE REF TO c2.

START-OF-SELECTION.
  CREATE OBJECT :kim,lee.
  SET HANDLER lee->letsgo FOR kim. "要使事件处理方法能够对事件进行响应,必须在运行时为相关事件注册该方法,

  kim->GO_BOWL( ).

[nangnangchuai]

split分割字符串

DATA: text TYPE string,
      itab TYPE TABLE OF string.

text = 'a abap is a programing language'.
SPLIT text AT space INTO TABLE itab.
LOOP AT itab INTO text.
  WRITE :/ text.
ENDLOOP.