5.Creating Objects
动态创建对象，创建数据对象或类对象。
5.1 create data
创建数据对象：CREATE DATA;
示例：
"动态对象
"CREATE DATA
"隐式定义数据类型
"1. CREATE DATA dref [area_handle].
"使用ABAP预定义类型
*2. CREATE DATA dref [area_handle]
* TYPE {abap_type|(name)}
* [LENGTH len] [DECIMALS dec].
"d,t,i,f,decfloat16,decfloat34,string,xstring
"不需要指定length,decimals
"c,n,x
"需要指定length
"p
"需要指定length,decimals
"使用已有Type
*3. CREATE DATA dref [area_handle]
* { {TYPE [LINE OF] {type|(name)}}
* | {LIKE [LINE OF] dobj} }.
"引用类型创建变量
*4. CREATE DATA dref [area_handle]
* TYPE HANDLE handle.
"创建reference变量
*5. CREATE DATA dref [area_handle]
* TYPE REF TO {type|(name)}.
"创建内表
*6. CREATE DATA dref [area_handle]
*{ {TYPE [STANDARD]|SORTED|HASHED TABLE OF [REF TO] {type|(name)}}
* | {LIKE [STANDARD]|SORTED|HASHED TABLE OF dobj} }
* [ {WITH [UNIQUE|NON-UNIQUE]
* {KEY {comp1 comp2 ...}|(keytab)}|{DEFAULT KEY}}
* | {WITH EMPTY KEY} ]
* [INITIAL SIZE n].
FORM f_create_obj.
TYPES:t_itab TYPE TABLE OF i WITH NON-UNIQUE KEY table_line.
DATA:lt_itab_ref TYPE REF TO t_itab.
DATA:i_ref TYPE REF TO i.
DO 10 TIMES.
IF lt_itab_ref IS INITIAL.
CREATE DATA lt_itab_ref.
ENDIF.
APPEND sy-index TO lt_itab_ref->*.
ENDDO.
IF i_ref IS INITIAL.
CREATE DATA i_ref.
ENDIF.
LOOP AT lt_itab_ref->* INTO i_ref->*.
WRITE:/ i_ref->*.
ENDLOOP.
"使用ABAP已有类型
DATA:lv_ref TYPE REF TO DATA.
CREATE DATA lv_ref TYPE P LENGTH 8 DECIMALS 2.
"使用type定义结构体，或数据库表结构
DATA:lt_ref TYPE REF TO DATA.
FIELD-SYMBOLS:<fs_wa> TYPE ANY.
FIELD-SYMBOLS:<fs_comp> TYPE ANY.
"创建数据
CREATE DATA lt_ref TYPE spfli.
ASSIGN lt_ref->* TO <fs_wa>.
SELECT * FROM spfli UP TO 1 ROWS INTO <fs_wa>.
"读取前四列
DO 4 TIMES.
ASSIGN COMPONENT sy-index OF STRUCTURE <fs_wa> TO <fs_comp>.
IF sy-subrc = 0.
WRITE:/ <fs_comp>.
ELSE.
EXIT.
ENDIF.
ENDDO.
ENDSELECT.
"动态数据类型
"CL_ABAP_DATADESCR
"CL_ABAP_ELEMDESCR
"element,i,c,n，string，decfoat等类型
"CL_ABAP_STRUCTDESCR, CL_ABAP_TABLEDESCR,CL_ABAP_REFDESCR
"structure,table,reference类型
DATA:lo_struct TYPE REF TO cl_abap_structdescr.
DATA:lt_comp_tab TYPE cl_abap_structdescr=>component_table.
DATA:ls_comp_tab LIKE LINE OF lt_comp_tab.
DATA:lv_ref1 TYPE REF TO DATA.
"get方法exception,CX_SY_STRUCT_CREATION
DATA:lo_excep TYPE REF TO cx_sy_struct_creation.
FIELD-SYMBOLS:<fs_struct> TYPE ANY.
FIELD-SYMBOLS:<fs_comp1> TYPE ANY.
FIELD-SYMBOLS:<fs_comp2> TYPE ANY.
"构造结构
ls_comp_tab-name = 'name'.
ls_comp_tab-type = cl_abap_elemdescr=>get_string( ).
APPEND ls_comp_tab TO lt_comp_tab.
ls_comp_tab-name = 'age'.
ls_comp_tab-type = cl_abap_elemdescr=>get_i( ).
APPEND ls_comp_tab TO lt_comp_tab.
"获取数据类型
TRY .
lo_struct = cl_abap_structdescr=>get( lt_comp_tab ).
"根据动态结构创建数据
CREATE DATA lv_ref1 TYPE HANDLE lo_struct.
"数据
ASSIGN lv_ref1->* TO <fs_struct>.
ASSIGN COMPONENT 'NAME' OF STRUCTURE <fs_struct> TO <fs_comp1>.
<fs_comp1> = 'Tom'.
ASSIGN COMPONENT 'AGE' OF STRUCTURE <fs_struct> TO <fs_comp2>.
<fs_comp2> = 10.
CATCH cx_sy_struct_creation INTO lo_excep.
MESSAGE lo_excep TYPE 'E'.
RETURN.
ENDTRY.
"根据类名
"CL_ABAP_STRUCTDESCR
* DATA:lv_ref2 TYPE REF TO DATA.
* DATA:lv_cls_name TYPE string.
* FIELD-SYMBOLS:<fs_cls> TYPE ANY.
* FIELD-SYMBOLS:<fs_attr> TYPE ANY.
* DATA:lo_oo_cls TYPE REF TO cl_oo_class.
* TRY .
* "获取类名
* CREATE OBJECT lo_oo_cls EXPORTING clsname = ''.
* lv_cls_name = lo_oo_cls->class-clsname.
* CATCH cx_class_not_existent.
* ENDTRY.
* lv_cls_name = '\PROGRAM=program名\CLASS=类名'.
* CREATE DATA lv_ref2 TYPE (lv_cls_name).
* ASSIGN lv_ref2->* TO <fs_cls>.
* ASSIGN ('<FS_CLS>->类attr名') TO <fs_attr>.
* WRITE:/ <fs_attr>.
ENDFORM.
5.2 create object
创建类对象：CREATE OBJECT;
示例2：
"CREATE OBJECT
"隐式定义类
*1. CREATE OBJECT oref [area_handle] [parameter_list].
"明确定义类
*2. CREATE OBJECT oref [area_handle]
* TYPE { class [parameter_list] }
* | { (name) [parameter_list|parameter_tables] }.
"创建object，有参构造
*[EXPORTING p1 = a1 p2 = a2 ...]
*[EXCEPTIONS exc1 = n1 exc2 = n2 ... [OTHERS = n_others]].
*[PARAMETER-TABLE ptab]
*[EXCEPTION-TABLE etab].
FORM f_create_obj1.
DATA: container TYPE REF TO cl_gui_container,
exc_ref TYPE REF TO cx_root,
exc_text TYPE string.
DATA: class TYPE string VALUE `CL_GUI_DIALOGBOX_CONTAINER`,
ptab TYPE abap_parmbind_tab,
ptab_line TYPE abap_parmbind.
ptab_line-name = 'PARENT'.
ptab_line-kind = cl_abap_objectdescr=>exporting.
GET REFERENCE OF CL_GUI_CONTAINER=>DESKTOP
INTO ptab_line-value.
INSERT ptab_line INTO TABLE ptab.
ptab_line-name = 'WIDTH'.
ptab_line-kind = cl_abap_objectdescr=>exporting.
GET REFERENCE OF 1000 INTO ptab_line-value.
INSERT ptab_line INTO TABLE ptab.
ptab_line-name = 'HEIGHT'.
ptab_line-kind = cl_abap_objectdescr=>exporting.
GET REFERENCE OF 300 INTO ptab_line-value.
INSERT ptab_line INTO TABLE ptab.
TRY.
CREATE OBJECT container TYPE (class)
PARAMETER-TABLE ptab.
CATCH cx_sy_create_object_error INTO exc_ref.
exc_text = exc_ref->get_text( ).
MESSAGE exc_text TYPE 'I'.
ENDTRY.
ENDFORM.
5.3 shared objects
Shared Objects:创建Object作为Shared Objects，定义类时使用语法：SHARED MEMORY ENABLED;
Area Class:定义Area,使用Tcode:SHMA。全局终结Area类：CL_SHM_AREA；所有Area类父类：CL_ABAP_MEMORY_AREA；
Areas
Areas-Basic Properties：
1. Area Name,示例:'CL_';2. Area Root Class, 是全局定义内存共享的Class;3. Client-Dependent Area,使用Client区分Area；4. Automatic Area Building；5. Transactional Area；
Areas-Fixed Area Properties:
1. Area Binding；2. Area Instance Versioning；
Area-Dynamic Area Properties:
1.Area Constructor Class，实现SHM_IF_SHM_BUILD_INSTANCE接口类，IF_SHM_BUILD_INSTANCE~BUILD类方法作为constructor方法；
2. Displacement Type，可能的displacement type:Displacement Not Possible, Displacement Possible。
Areas-Runtime-Dependent Area Properties:
1. Area Build Type，可能值：No Autostart、Autostart for Read Request、Autostart for Read Request and Every Invalidation；
2. Size of an Area Instance Version，可能值:No limit、Maximum ... KB；
3.Number of Versions of an Area Instance，可能值：No limit、Maximum ...；
4.Lifetime of an Area Instance,可能值: No specification、Expires after ... minutes、Refresh after ... minutes、Without read access ... minutes；
Area Instance Versions
管理存储Shared Objects。Tcode: SHMM,overview of area instance。类：CL_SHM_UTILITIES；
Area Handles：
Area Handles是area class的实例；
Area Lock, Creating Area Instance Versions, ATTACH_FOR_WRITE;Changing Area Instance Versions,ATTACH_FOR_UPDATE;Reading Area Instance Versions,ATTACH_FOR_READ;
Deactivating Area Handles, 移除Reading Lock,DETACH; 移除Changing Lock,并提交修改，DETACH_COMMIT; 移除Changing Lock,并回滚修改，DETACH_ROLLBACK；DETACH_AREA，DETACH_ALL_AREAS，一次移除多个绑定；
Additional Methods，1. Methods INVALIDATE_INSTANCE or INVALIDATE_AREA；
2. Methods FREE_INSTANCE or FREE_AREA；3. Method GET_INSTANCE_INFOS；4. Methods GET_LOCK_KIND, IS_VALID, IS_ACTIVE_VERSION, IS_SHARED, HAS_ACTIVE_PROPERTIES and GET_DETACH_INFO，Area handle信息；5 .BUILD method,调用area constructor方法；
Area Instance Versions状态：1.Building;2.Active;3.Obsolete;4. Expired;
Shared Objects
Access Shared Objects,使用GET_HANDLE_BY_OREF, GET_HANDLE_BY_DREF, and GET_HANDLE_BY_DATA获取CL_ABAP_MEMORY_AREA类实例；
Shared Objects创建，CREATE OBJECT oref AREA HANDLE handle；
CREATE DATA dref AREA HANDLE handle；
Area类结构：
CL_ABAP_MEMORY_AREA
--CL_SHM_AREA
--Area Classes
--CL_IMODE_AREA
CL_ABAP_MEMORY_AREA is the superclass of all area classes.
CL_SHM_AREA is the superclass of all self-defined area classes.
CL_IMODE_AREA is a predefined area class for the internal session.
Area接口:
IF_SHM_BUILD_INSTANCE
--Area Constructor Class
CL_ABAP_MEMORY_AREA类结构：
1.Static Methods
GET_HANDLE_BY_OREF
GET_HANDLE_BY_DREF
GET_HANDLE_BY_DATA
2.Instance Methods
IS_SHARED
IS_VALID
IS_ACTIVE_VERSION
HAS_ACTIVE_PROPERTIES
GET_DETACH_INFO
CL_SHM_AREA类结构：
1.Instance Attributes
PROPERTIES
INST_NAME
CLIENT
Static Methods
MULTI_ATTACH
DETACH_ALL_AREAS
2.Instance Methods
DETACH
DETACH_COMMIT
DETACH_ROLLBACK
GET_LOCK_KIND
GET_ROOT
3.Instance Events
SHM_COMMIT_EVENT
SHM_ROLLBACK_EVENT
示例：DEMO_SHARED_OBJECTS