ABAP grammar learning (ALV)

First of all, the most commonly used class group is ：

TYPE-POOLS:SLIS.

There are many in this type group ALV And structured data types （ adopt TYPE To define the ,） We are writing ALV The form needs to be called .
The common ones are ：

Let's write the first one ALV The basic process of the program is as follows ：

First step ： Define the tables to be used , namely TALBES Definition section , Then define TYPE-POOLS:SLIS.

The second step ： Definition “1” These data types or entity objects of inner tables mentioned in

The third step ： Define some variables that need to be used , For example, we often define ：
Data: w_repid like sy-repid, "ABAP Program , We usually take the current program
w_callback_ucomm type sils_formname, “ Character , function
w_print type slis_print_alv, " Type group
w_layout type slis_layout_alv, " Type group
w_html_top_of_page type slis_formname, " Character
w_fieldcat_alv like line of i_fieldcat_alv, “ Referenced from the above data structure type
w_excluding like line of i_excluding, “ ditto
w_events like line of i_events, “ ditto
w_event_exit like line of i_event_exit, “ ditto
w_list_comments like line of i_list_comments.“ ditto

Step four ： Define your own selection screen
Step five ： Definition INITIALIZATION part , In this part, it is often necessary to specify w_repid Value , w_repid = sy-repid
Step six ： start-of-selection part
Use a sub function to complete the pair ALV Assignment of form title area (i_list_comments).
Use a subfunction to complete the data grabbing you need
Use a subfunction to complete the column name row of the list to be displayed （ first line ） The relevant assignment of （i_fieldcat_alv） And settings
Use a subfunction to set the output format (i_layout), For example, double click a record to open a dialog box ？ Which function key is used to trigger and so on
Use a subfunction FORM DISPLAY_DATA To show the data that we have encapsulated separately , You need to call two common FUNCTION MODULE：
FUNCTION ‘REUSE_ALV_GRID_DISPLAY’ “ Used to display form data
FUNCTION ‘REUSE_ALV_COMMENTARY_WRITE’ “ Used to display the form title