调用 REUSE_ALV_GRID_DISPLAY 时崩溃“尚未分配字段符号”

Question

While displaying an ALV I get a crash report when executing the program. To create an ALV I have followed a few tutorials and stuff and at the moment it looks like this:

TYPE-POOLS: slis. 
*build field catalog
DATA: it_fieldcat TYPE slis_t_fieldcat_alv,
    wa_fieldcat TYPE slis_fieldcat_alv,
    repid TYPE sy-repid.

REFRESH it_fieldcat.
CLEAR wa_fieldcat.
wa_fieldcat-reptext_ddic = 'Table ID'.
wa_fieldcat-fieldname    = 'table_id'.
wa_fieldcat-tabname      = 'lt_where_used_data_of_coll'.
wa_fieldcat-outputlen    = '18'.
APPEND wa_fieldcat TO it_fieldcat.

CLEAR wa_fieldcat.
wa_fieldcat-reptext_ddic = 'Table Description'.
wa_fieldcat-fieldname    = 'table_description'.
wa_fieldcat-tabname      = 'lt_where_used_data_of_coll'.
wa_fieldcat-outputlen    = '40'.
APPEND wa_fieldcat TO it_fieldcat.

CLEAR wa_fieldcat.
wa_fieldcat-reptext_ddic = 'Numer of Records Found'.
wa_fieldcat-fieldname    = 'nr_of_records'.
wa_fieldcat-tabname      = 'lt_where_used_data_of_coll'.
wa_fieldcat-outputlen    = '30'.
APPEND wa_fieldcat TO it_fieldcat.

*pass data and field catalog to ALV function module
CALL FUNCTION 'REUSE_ALV_GRID_DISPLAY'
EXPORTING
  i_callback_program      = repid
  it_fieldcat             = it_fieldcat
  i_structure_name        = 'lty_where_used_data_of_coll'
TABLES
  t_outtab                = lt_where_used_data_of_coll.

'lt_where_used_data_of_coll' is my local table that I have already filled with a working function earlier in my program. This function works and I have tested it and the table fills itself with data. My next step was displaying this data to the end user. The error report I receive when executing this program is:

Short text: Field symbol has not yet been assigned.

What happened?:

Error in the ABAP Application Program.
    The current ABAP program "SAPLSLVC" had to be terminated because it has
    come across a statement that unfortunately cannot be executed.

Error analysis:

You attempted to access an unassigned field symbol
(data segment "-1").

Trigger Location of Runtime Error :

    Program                                 SAPLSLVC
    Include                                 LSLVCF36
    Row                                     3,273
    Module type                             (FORM)
    Module Name                             FILL_DATA_TABLE

I really don't know how to start finding my mistake. It seems like it runs bad when calling a function from ABAP itself.

Any help is much appreciated.

EDIT: As was suggested I implemented another way of displaying an ALV that can be found below. This way works fine and gives no errors. Question still remains why the older method does give me an error.

I replaced the entire block of code above with this:

DATA alv TYPE REF TO cl_salv_table. DATA message TYPE REF TO cx_salv_msg.

*initialize ALV
TRY.
  cl_salv_table=>factory(
    IMPORTING
      r_salv_table = alv
    CHANGING
      t_table      = lt_where_used_data_of_coll ).
CATCH cx_salv_msg INTO message.
  " error handling
ENDTRY.
*display ALV
alv->display( ).

Answer 1

why the older method does give me an error

Field catalog names are case sensitive. Capitalize every fieldname and tabname value and see if the error's still there. Also make sure that the names match those of your internal table lt_where_used_data_of_coll