如何解决ALV的负数符号前显的问题

1、建立自定义函数
1.1 整数显示
FUNCTION CONVERSION_EXIT_Z0002_OUTPUT.
*"----------------------------------------------------------------------
*"*"Local interface:
*" IMPORTING
*" REFERENCE(INPUT)
*" EXPORTING
*" REFERENCE(OUTPUT)
*"----------------------------------------------------------------------
DATA: OUTPUT1(12) TYPE C,
OUTDATUM TYPE INT4.
IF INPUT <> SPACE.
OUTDATUM = INPUT.
if input > 0.
move OUTDATUM TO OUTPUT .
else.
OUTDATUM = OUTDATUM * ( -1 ).
move OUTDATUM TO OUTPUT1 .
CONCATENATE '-' output1 into output.
CONDENSE output NO-GAPS .
endif.
ELSE.
OUTPUT = SPACE.
ENDIF.
ENDFUNCTION.
1.2 浮点数显示
FUNCTION conversion_exit_zsign_output.
*"----------------------------------------------------------------------
*"*"Local interface:
*" IMPORTING
*" REFERENCE(INPUT)
*" EXPORTING
*" REFERENCE(OUTPUT)
*"----------------------------------------------------------------------

DATA: output1(19) TYPE c,
output2(19),
outdatum TYPE p DECIMALS 2.
IF not input is initial.
outdatum = input.
IF input > 0.
WRITE outdatum TO output1 ."RIGHT-JUSTIFIED .
CONCATENATE ' ' output1 INTO output1.
ELSE.
outdatum = outdatum * ( -1 ).
WRITE outdatum TO output1 ."RIGHT-JUSTIFIED.
CONCATENATE '-' output1 INTO output1.
ENDIF.
ELSE.
* output = '0.00'.
CLEAR output1.
ENDIF.
CONDENSE output1 NO-GAPS .
WRITE output1 TO output2 RIGHT-JUSTIFIED .
output = output2.
ENDFUNCTION.

2、设置ALV输出格式字段格式
clear ls_fcat.
ls_fcat-fieldname = 'INT4'.
ls_fcat-inttype = 'I'.
ls_fcat-intlen = 10.
ls_fcat-col_pos = l_lin.
ls_fcat-seltext_s = ls_fcat-fieldname.
ls_fcat-seltext_m = ls_fcat-fieldname.
ls_fcat-seltext_l = ls_fcat-fieldname.
ls_fcat-edit_mask = '==Z0002'.
append ls_fcat to ct_fcat.

3、调用函数就可达到负数符号前显的效果。
call function 'REUSE_ALV_GRID_DISPLAY'
exporting
it_fieldcat = lt_fcat
tables
t_outtab = gt_outtab
exceptions
program_error = 1
others = 2.