OO(面向对象在ABAP中的应用)详解编程语言

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吧

* 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.

* 现在是用到事件处理的例子.

 

 

*

 

* Using the subclass FactoryWorker with event

*

*定义个员工实例

*再定义个处理事件的对象

 

 DATA: LazyJohn TYPE REF TO FactoryWorker,

 FireHim TYPE REF TO FireEmployee.

 

 CREATE OBJECT: LazyJohn,

 FireHim.

 

 

 

* The SET HANDLER statement, registers a runtime trigger.

* It links a list of handler methods to corresponding event triggers

* Each SET HANDLER statement creates an entry in an event handler table

 

* 为LAZYJOHN设置一个处理HANDLER ,具体的方法是

 SET HANDLER FireHim- YouAreFired FOR LazyJohn.

 

 LazyJohn- nEmployeeNo = 1500.

 LazyJohn- cEmployeeName = Lazy John .

 LazyJohn- iNoOfUnits = 90.

 LazyJohn- iExtraNoUnits = 500.

 LazyJohn- iPayPerUnit = 3.

 WRITE: / Lazy John has produced less than 100 units .

 MyPay = LazyJohn- CalculatePay( ).

原创文章，作者：Maggie-Hunter，如若转载，请注明出处：https://blog.ytso.com/20163.html

c