Getting started with ALV

First step , Type group
TYPE-POOLS:SLIS.
There are many in this type group ALV And structured data types

We often use

data: 	i_fieldcat_alv type slis_t_fieldcat_alv wth header line. " It is used to store the column name of the form that we will display in the form display area , The data type of each column name and other related attribute information in the list header .
			i_layout type slis_layout_alv.			"ALV The format of 
			i_list_comments type slis_t_listheader.			" The data type used to fill in the form header area 
		
			" The use of the following three types depends on the situation 
			i_events   		type		silis_t_event,
			i_event_exit		type		slis_t_event_exit,
			i_excluding    	type slis_t_extab.

The second step ： Write ALV Basic flow

First step ： Define the tables to be used , namely TALBES Definition section , Then define TYPE-POOLS:SLIS.
The second step ： Define the entity objects of these data types or inner tables in the first step .
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 slis_forname_alv,	" Character , function 
			w_print							type slis_print_alv		" Type group 
			w_layout							type	slis_layout_alv,	" Type group 
			w_html_top_of_age			type	slis_forname,		" 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 

Step four ： Define your own selection screen
Step five ： Definition INITIALIZATION part , In this part, it is often necessary to specify w_repid
w_repid = sy-repid "sy-repid It's a system variable .. The current program name can be recorded in the program in real time

Step six ：start-of-selection part
1. Use a sub function to complete the pair alv Assignment depends on the form title area （i_list_comments）.
2. Use a subfunction to complete the data grabbing you need
3. 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
4. Use a subfunction to set the output format , For example, double clicking a record will pop up a dialog box ？ Which function key is used to trigger and so on
5. 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