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SAP ABAP/4学习–学习使用OO在ABAP中.简单入门概念.用个例子来说明

2013年01月10日 ⁄ 综合 ⁄ 共 3955字 ⁄ 字号 评论关闭

ABAP Object Oriented Programming

 

 

 

 

REPORT ZHEF_ABAP_OBJECTS_EXAMPLE2.

************************************************************************

* Local classes Example 2

* Using enheritance

* Raising and handling events

************************************************************************

 

************************************************************************

* Super class Empolyee

************************************************************************

 

*定义一个父类,只是定义里面的一些数据类型,

* 具体的方法和内容在下面实现.

CLASS Employee DEFINITION.

*定义公共部分的数据和方法

PUBLIC SECTION.

  DATA:

      nEmployeeNo(4)       type n,   雇员员工号

      cEmployeeName(30)    type c,   雇员姓名

      iNoOfUnits           type i,   生产的的单元的数量

      iPayPerUnit          type i.   每个单元的价格

 

*定义两个方法,一个是输出,一个是输入

  METHODS:

      CalculatePay RETURNING VALUE(iPay) TYPE i,

      WritePay     IMPORTING VALUE(iPay) TYPE i.

ENDCLASS.

 

 

*这里是具体的实现的

CLASS Employee IMPLEMENTATION.

*实现上面的方法

  METHOD CalculatePay.

 

    iPay = iNoOfUnits * iPayPerUnit.

  ENDMETHOD.

 

  METHOD WritePay.

 

    WRITE: / 'The pay for employee ',

             nEmployeeNo, cEmployeeName,

             ' is : ', iPay.

  ENDMETHOD.

 

ENDCLASS.

 

************************************************************************

* Subclass Factory Worker

*

* The class FactoryWorker is a subclass of the superclass Employee.

* Note that the attribute iExtraNoUnits have been added and the

* method CalculatePay has been redefined.

 

*

************************************************************************

 

 

 

 

 

 

 

*定义一个子类.从父类中继承过来

CLASS FactoryWorker DEFINITION INHERITING FROM Employee.

  PUBLIC SECTION.

*   定义个事件.  

EVENTS: LazyEmployee.  

 

*  增加一个属性 

    DATA: iExtraNoUnits type i.

 

*覆盖父的方法,现在从新定义CalculatePay.

    METHODS:

*     Redefinition af the CalculatePay method from the Superclass

      CalculatePay REDEFINITION.

 

ENDCLASS.

 

*现在实现这个个子类.

CLASS FactoryWorker IMPLEMENTATION.

  METHOD CalculatePay.

* 从新定义方法

 

    iPay = ( iNoOfUnits * iPayPerUnit ) +

           ( iExtraNoUnits * iPayPerUnit * 2 ).

          

*   抛出处理

    IF iNoOfUnits < 100.

      raise event LazyEmployee.     

    ENDIF.

  ENDMETHOD.

 

ENDCLASS.

 

************************************************************************

* This class only to show how you can handle an event that have been

* raised in another class

************************************************************************

* 这个类只能处理一个在其他类中抛出的事件.

* 被开除的员工的类的定义

CLASS FireEmployee DEFINITION.

 

  PUBLIC SECTION.

*   Method for handling the event LazyEmployee in the FactoryWorker

*   subclass.

*   定义YOUAREFIRED方法为FACTORYWORKER类中的LAZYEMPLOYEE事件.  

    METHODS YouAreFired

            FOR EVENT LazyEmployee

            OF FactoryWorker.

ENDCLASS.

 

 

 

 

 

 

 

 

*来实现这个CLASS

* 然后实现具体的方法,就是输出一句话,具体处理.

CLASS FireEmployee IMPLEMENTATION.

  METHOD YouAreFired.   

    WRITE:/ 'You lazy worker, you have produced less than 100 units.'

           color col_heading,

           'YOU ARE FIRED !!!' color col_negative intensified.

 

  ENDMETHOD.

ENDCLASS.

 

 

*下面是使用CLASS

************************************************************************

* U S I N G   T H E   C L A S S E S

************************************************************************

 

DATA: MyPay TYPE i.

 

START-OF-SELECTION.

*-----------------------------------------------------------------------

* Using the superclass Employee

*-----------------------------------------------------------------------

 

* Declare new Employee from the EmployeeClass

 

  DATA: SamSmith TYPE REF TO Employee.

 

  CREATE OBJECT: SamSmith.

  SamSmith->nEmployeeNo = 433.

  SamSmith->cEmployeeName = 'Sam Smith'.

  SamSmith->iNoOfUnits = 150.

  SamSmith->iPayPerUnit = 3.

  MyPay = SamSmith->CalculatePay(  ).

  CALL METHOD SamSmith->WritePay( MyPay ).

  SKIP.

 

*-----------------------------------------------------------------------

* Using the subclass FactoryWorker

*-----------------------------------------------------------------------

 

* Declare new FactoryWorker as subclass of the EmployeeClass

  DATA: JessicaJones TYPE REF TO FactoryWorker.

 

  CREATE OBJECT: JessicaJones.

 

  JessicaJones->nEmployeeNo = 1500.

  JessicaJones->cEmployeeName = 'Jessica Jones'.

  JessicaJones->iNoOfUnits = 300.

  JessicaJones->iExtraNoUnits = 500.      子类中额外的一些单元

  JessicaJones->iPayPerUnit = 3.

  MyPay = JessicaJones->CalculatePay(  ).

  CALL METHOD JessicaJones->WritePay( MyPay ).

  SKIP.

 

 

 

* 以下是处理一个事件所写的例子,上面的两个,一个用到父类,一个用到了子类

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