动态内表

动态内表相当于从一张表里捞数据，filecat是不固定的，想用什么传什么。

例子：

type-pools: slis.

data: it_fcat type slis_t_fieldcat_alv,

      is_fcat like line of it_fcat.

data: it_fieldcat type lvc_t_fcat, "存储内表想要的字段

      is_fieldcat like line of it_fieldcat.

data: new_table type ref to data. "引用变量,指向任意类型，但在创建时必须指定对象类型

data: new_line type ref to data.

field-symbols: <l_table> type any table,

<l_line> type any,

<l_field> type any.



call function 'REUSE_ALV_FIELDCATALOG_MERGE'
"把表SYST的字段给it_fcat[]
exporting

i_structure_name = 'SYST'

changing

ct_fieldcat = it_fcat[].

loop at it_fcat into is_fcat where not reptext_ddic is initial.

move-corresponding is_fcat to is_fieldcat.

is_fieldcat-fieldname = is_fcat-fieldname.

is_fieldcat-ref_field = is_fcat-fieldname.

is_fieldcat-ref_table = is_fcat-ref_tabname.

append is_fieldcat to it_fieldcat.

endloop.


"创建动态内表
call method cl_alv_table_create=>create_dynamic_table

exporting

it_fieldcatalog = it_fieldcat

importing

ep_table = new_table.



assign new_table->* to <l_table>.

create data new_line like line of <l_table>.

assign new_line->* to <l_line>.



do 30 times.

assign component 'SUBRC' of structure <l_line> to <l_field>.
"将<l_line>中SUBRC组件赋给<l_field>
<l_field> = sy-index.

insert <l_line> into table <l_table>.

enddo.

loop at <l_table> assigning <l_line>.

assign component 'SUBRC' of structure <l_line> to <l_field>.

write <l_field>.

endloop.

assign component 'SUBRC' of structure <l_line> to <l_field> 这句话可谓是精髓，不用考虑你的字段到底是什么，反正会给你分配
优点：由于FILECAT不是写死的，就比较灵活
缺点：个人觉得麻烦