ABAP 获取屏幕字段值，field-symbols，assign..TO.. 相关知识实例
以QA32质量放行程序为例子：
由于这个两个值都在结构RQEVA中，为了方便这里获取整个结构值，最后利用指针指向这个程序的这个结构即可获取当前值，具体写法如下：
program zqme_check_at_qa11.
form check_ud using new_insplot type qals ud_data type qave.
data: lv_aufnr type qals-aufnr.
data: lt_status type table of jstat.
data: ls_status type jstat.
data: lv_objnr type jsto-objnr.
data: lt_mseg type table of mseg.
data: lt_mch1 type table of mch1,
ls_mch1 type mch1,
lv_value type c,
lv_valuef type c.
"获取屏幕字段值
data lc_string(25) value '(SAPMQEVA)RQEVA-ZUS_NEU_N'.
data lc_string_f(25) value '(SAPMQEVA)RQEVA-US_NEU_F'.
data lc_string_d(25) value '(SAPMQEVA)RQEVA-MHD_01'.
data lc_string_e(25) value '(SAPMQEVA)RQEVA-VCODE'.
data lc_string_g(25) value '(SAPMQEVA)QALS-MATNR'. "程序+表+字段
data: lv_auth type rqeva-zus_neu_n.
data: lt_qmel type table of qmel.
data: ls_qmel type qmel.
data: lv_charg type qals-charg.
data: lt_tj02t type table of tj02t,
ls_tj02t type tj02t.
"获取屏幕字段值，类1. FIELD-SYMBOLS：FIELD-SYMBOLS 是一个关键字，用于声明一个指针变量，允许在运行时指向内存中的"某个数据对象。通过 FIELD-SYMBOLS，可以在不提前指定具体变量名的情况下，将一个"变量看作指针，并在运行时动态绑定到数据对象。
field-symbols: <fs> type any.
field-symbols: <fs_f> type any.
field-symbols: <fs_date> type any.
field-symbols: <fs_vcode> type any.
field-symbols: <fs_matnr> type any.
"通过变量名动态访问变量2. ASSIGN：
ASSIGN 是一个指令语句，用于将一个数据对象的引用分配给 FIELD-SYMBOLS 变量。在运行时，使用 ASSIGN 将数据对象分配给 FIELD-SYMBOLS 变量后，就可以通过 FIELD-SYMBOLS 变量直接访问和操作数据对象。示例：
assign (lc_string) to <fs> .
assign (lc_string_f) to <fs_f> .
assign (lc_string_d) to <fs_date>.
assign (lc_string_e) to <fs_vcode>.
assign (lc_string_g) to <fs_matnr>.
clear:lv_auth,
lv_value,
lv_valuef.
if <fs> is assigned."restricted
lv_value = <fs>.
endif.
if <fs_f> is assigned."unrestricted
lv_valuef = <fs_f>.
endif.
data ls_mara type mara.
data ls_zmmt002 type zmmt002.
clear ls_mara.
clear ls_zmmt002.
check new_insplot-charg is not initial.
if <fs_f> is assigned and <fs_f> = 'X'. "非限制状态
if ud_data-vcode = 'X'."vcode = 'X' 表示限制放行
message e009(zqm01).
endif.
endif.
if <fs> is assigned and <fs> = 'X'."限制状态
if ud_data-vcode = 'A'."表示非限制放行
message e001(zqm01).
endif.
endif.
clear ls_mara.
select single * from mara into ls_mara where matnr = new_insplot-matnr.
if ls_mara-mtart = 'ZXXX'and ud_data-vcode is initial ."
message e002(zqm01).
endif.
check ud_data-vcode = 'A'.
cl_salv_bs_runtime_info=>set( exporting display = abap_false
metadata = abap_false
data = abap_true ).
field-symbols:<fs_table> type any table,
<fs_any> type any. "LIKE LINE OF IT_TAB
data:gr_data type ref to data.
clear gr_data.
unassign <fs_table>.
submit zqmr_003 "LX02
with pa_charg eq new_insplot-charg
and return.
try.
cl_salv_bs_runtime_info=>get_data_ref( importing r_data = gr_data ).
assign gr_data->* to <fs_table>.
catch cx_salv_bs_sc_runtime_info.
endtry.
cl_salv_bs_runtime_info=>clear_all( ).
data: lt_data type table of zqms_batchtrace,
ls_data type zqms_batchtrace.
refresh: lt_data.
if <fs_table> is assigned.
unassign <fs_any>.
loop at <fs_table> assigning <fs_any>.
clear ls_data.
ls_data = <fs_any>.
if ( ls_data-zustd = '批量限制'
or ls_data-zustd = 'Batch limit' )
and ls_data-charg ne new_insplot-charg.
message e010(zqm01) with ls_data-charg .
exit.
endif.
if ls_data-qmnum ne '' and ls_data-zflag = 'X'
and ls_data-charg ne ''.
message e005(zqm01) with ls_data-qmnum .
exit.
endif.
endloop.
unassign <fs_any>.
endif.
check ud_data-vcode = 'A'.
call function 'ZQM_ECC_UPDATE_BATCH' " IN UPDATE TASK
exporting
is_insplot = new_insplot.
endform.
form update_batch using new_insplot type qals .
check new_insplot-charg is not initial.
set update task local .
call function 'ZQM_ECC_UPDATE_BATCH' in update task
exporting
is_insplot = new_insplot.
endform.
