图片分类展示网站源码,如何建设一个自己的网站,网站产品展示,长沙网站建设外贸通过几个例子#xff0c;由浅入深讲解 ABAP 动态编程。ABAP 动态编程主要通过 RTTS (Runtime Type Services) 来实现#xff0c;包括 RTTI 和 RTTC:
运行时类型标识#xff08;RTTI#xff09; – 提供在运行时获取数据对象的类型定义的方法。运行时类型创建#xff08;R…通过几个例子由浅入深讲解 ABAP 动态编程。ABAP 动态编程主要通过 RTTS (Runtime Type Services) 来实现包括 RTTI 和 RTTC:
运行时类型标识RTTI – 提供在运行时获取数据对象的类型定义的方法。运行时类型创建RTTC – 提供在运行时使用任何类型定义创建数据对象的方法。
动态程序的基本要素
第一个例子主要演示构建程序的最基本要素。 第一步创建 structure descriptor 和 table descriptor主要用于后面动态构建内表的结构
data struct_descr type ref to cl_abap_datadescr.
data table_descr type ref to cl_abap_tabledescr.struct_descr ? cl_abap_structdescrdescribe_by_name( SFLIGHTS ).
table_descr ? cl_abap_tabledescrcreate( p_line_type struct_descr ).第二步基于 table descriptor 创建泛型的 data reference object:
data table_dref type ref to data.
create data table_dref type handle table_descr.第三步使用 field symbol将 table reference object 指向 field symbol。
field-symbols table type any table.
assign table_dref-* to table.这样就动态创建了一个内表 table。第一个完整的例子
report z_dynamic_table_01.data gr_alv type ref to cl_salv_table.data struct_descr type ref to cl_abap_datadescr.
data table_descr type ref to cl_abap_tabledescr.struct_descr ? cl_abap_structdescrdescribe_by_name( SFLIGHTS ).
table_descr ? cl_abap_tabledescrcreate( p_line_type struct_descr ).data table_dref type ref to data.
create data table_dref type handle table_descr.field-symbols table type any table.
assign table_dref-* to table.select * from sflights up to 10 rows into corresponding fields of table table.try.call method cl_salv_tablefactoryimportingr_salv_table gr_alvchangingt_table table.catch cx_salv_msg .
endtry.gr_alv-display( ).动态程序的灵活性
如果只是从 SFLIGHTS 表获取数据当然没必要使用动态程序因为它让程序更加复杂。我们对上面的程序进行修改支持在选择屏幕中输入任意表名都能够在 ALV 中显示。
report z_dynamic_table_02.data gr_alv type ref to cl_salv_table.data struct_descr type ref to cl_abap_datadescr.
data table_descr type ref to cl_abap_tabledescr.parameters tab_name type dd02l-tabname.start-of-selection.struct_descr ? cl_abap_structdescrdescribe_by_name( tab_name ).table_descr ? cl_abap_tabledescrcreate( p_line_type struct_descr ).data table_dref type ref to data.create data table_dref type handle table_descr.field-symbols table type any table.assign table_dref-* to table.select * from (tab_name) up to 10 rows into corresponding fields of table table.try.call method cl_salv_tablefactoryimportingr_salv_table gr_alvchangingt_table table.catch cx_salv_msg .endtry.gr_alv-display( ).构建动态程序所需的字段
第一个例子主要是演示动态程序的基本要素一般情况下我们不需要获取一个数据表的所有字段这样就需要创建需要的字段。下面的示例演示了创建字段的方法。示例仍然从 sflights 中获取数据然后在 ALV 中显示。只需要 CARRID, CONNID, CARRNAME 和 FLDATE 四个字段。
report z_dynamic_table_03.data gr_alv type ref to cl_salv_table.data gs_component type cl_abap_structdescrcomponent.
data gt_component type cl_abap_structdescrcomponent_table.data struct_descr type ref to cl_abap_datadescr.
data table_descr type ref to cl_abap_tabledescr.data carrid type sflights-carrid.
data connid type sflights-connid.
data carrname type sflights-carrname.
data fldate type sflights-fldate.try.gs_component-name CARRID.gs_component-type ? cl_abap_datadescrdescribe_by_data( carrid ).append gs_component to gt_component.gs_component-name CONNID.gs_component-type ? cl_abap_datadescrdescribe_by_data( connid ).append gs_component to gt_component.gs_component-name CARRNAME.gs_component-type ? cl_abap_datadescrdescribe_by_data( carrname ).append gs_component to gt_component.gs_component-name FLDATE.gs_component-type ? cl_abap_datadescrdescribe_by_data( fldate ).append gs_component to gt_component.struct_descr ? cl_abap_structdescrcreate( p_components gt_component ).table_descr ? cl_abap_tabledescrcreate( p_line_type struct_descr ).data table_dref type ref to data.create data table_dref type handle table_descr.field-symbols table type any table.assign table_dref-* to table. Select data from database and fill dynamically created tableselect * from sflights up to 10 rows into corresponding fields of table table.try.call method cl_salv_tablefactoryimportingr_salv_table gr_alvchangingt_table table.catch cx_salv_msg .endtry.gr_alv-display( ).catch cx_root.
endtry.动态程序实现行转列
最后给出一个稍微综合一点的示例对于给定的数据 实现行转列并在 ALV 中显示 完整代码
report z_dynamic_table_rtts.type-pools: slis .types:begin of gfirst_typ,vend(6) type c,month(5) type c,amt type i,end of gfirst_typ .* RTTS declarations
data struct_descr type ref to cl_abap_datadescr.
data table_descr type ref to cl_abap_tabledescr.
data gs_component type cl_abap_structdescrcomponent.
data gt_component type cl_abap_structdescrcomponent_table.* Dynamice table declarations
data table_dref type ref to data.
data line_dref type ref to data.* Field symbol decalrations
field-symbols: gfs_line, gfs_line1.
field-symbols: gfs_table type standard table, fld.data it_zdemo type standard table of gfirst_typ.
data wa_zdemo like line of it_zdemo.* SALV declarionts.
data lo_cols type ref to cl_salv_columns.
data lo_salv_table type ref to cl_salv_table.
data lo_column type ref to cl_salv_column.
data col_name(30) type c.
data col_desc(20) type c.start-of-selection.* Populate the initial input table.
* Usually this input table contents will be popluated at run time,
* which raises the requirement of dynamic table.
* The talbe contens are filled here for illustration purpose.perform fill_table using:V100 JAN 100,V100 FEB 250,V200 FEB 200,V300 FEB 150,V200 MAR 250,V300 MAR 300,V100 APR 200,V100 MAY 100,V200 MAY 50,V300 MAY 125,V400 MAY 475.* Write the datawrite : / Initial internal table.write : /(6) Vendor, (12) Month, (3) Amt.loop at it_zdemo into wa_zdemo.write : / wa_zdemo-vend, wa_zdemo-month, wa_zdemo-amt.clear wa_zdemo.endloop.* Create structure of dyanmic internal table.gs_component-name VEND.gs_component-type ? cl_abap_datadescrdescribe_by_data( wa_zdemo-vend ).append gs_component to gt_component .* Loop throught the internal table creating a column for every distinct monthloop at it_zdemo into wa_zdemo.
* Search the component table if the month column already exists.read table gt_component into gs_component with key name wa_zdemo-month.if sy-subrc ne 0.
* The name of the column would be the month
* and the data type would be the same as the amount filed of intenal talegs_component-name wa_zdemo-month.gs_component-type ? cl_abap_datadescrdescribe_by_data( wa_zdemo-amt ).append gs_component to gt_component.endif.clear: gs_component, wa_zdemo.endloop.struct_descr ? cl_abap_structdescrcreate( p_components gt_component ).table_descr ? cl_abap_tabledescrcreate( p_line_type struct_descr ).create data table_dref type handle table_descr.create data line_dref type handle struct_descr.assign table_dref-* to gfs_table.assign line_dref-* to gfs_line.* Fill vendor fieldloop at it_zdemo into wa_zdemo.read table gfs_table into gfs_line with key (VEND) wa_zdemo-vend.if sy-subrc ne 0.assign component VEND of structure gfs_line to fld.fld wa_zdemo-vend.append fld to gfs_table.endif.clear wa_zdemo.endloop.* Aggregate data.loop at it_zdemo into wa_zdemo.read table gfs_table assigning gfs_line with key (VEND) wa_zdemo-vend.loop at gt_component into gs_component.if gs_component-name wa_zdemo-month.if fld is assigned.unassign fld.endif.assign component gs_component-name of structure gfs_line to fld.fld fld wa_zdemo-amt.endif.endloop.clear wa_zdemo.endloop.* ALV showtry.cl_salv_tablefactory(importingr_salv_table lo_salv_tablechangingt_table gfs_table).catch cx_salv_msg.endtry.* Get columns objectlo_cols lo_salv_table-get_columns( ).* Individual column namesloop at gt_component into gs_component.try.col_name gs_component-name.lo_column lo_cols-get_column( col_name ).if col_name VEND.col_desc Vendor.else.concatenate col_name 13 into col_desc.endif.lo_column-set_medium_text( col_desc ).lo_column-set_output_length( 10 ).catch cx_salv_not_found.endtry.endloop.* Display tablelo_salv_table-display( ).*---------------------------------------------------------------------*
* Form fill_table
*---------------------------------------------------------------------*
form fill_table using p_fld1 type gfirst_typ-vendp_fld2 type gfirst_typ-monthp_fld3 type gfirst_typ-amt.clear wa_zdemo.wa_zdemo-vend p_fld1.wa_zdemo-month p_fld2.wa_zdemo-amt p_fld3.append wa_zdemo to it_zdemo.endform. fill_table
