教程链接： www.guru99.com/abap-tutorial.html

1. All about ABAP Report programming.

SAP-ABAP contains two types of programs-- Report programs & Dialog program. Report programs are used when large amounts of data needs to be displayed.

Selection screen:

• Parameters: accommodate only one value (can also be used as checkboxes and radiobuttons).

• Selection-options: a range of values or a set of values

Events:

Abap report programs are event driven programs.

• Load-of-program

• Initialization : executed before the selection screen is displayed.

• At Selection-Screen: the event is processed when the selection screen has been processed. Validation & Checks values happen here.

• Start-of-Selection: The program starts selection from tables

• End-of-selection:

Format the report:

2. Dialog Programming Tutorial

A user dialog is any form of interaction between the user and the program

• Entering data

• Choosing a menu item

• Clicking a button

• Clicking or double clicking an entry

Dialog programs are created with types as ‘M’-Module Pool. They can’t be executed independently and must be attached to at least one transaction code in which you specify an initial screen.

The components of a dialog program are:

• Transaction code: a transaction code is linked to an ABAP program and an initial screen

• Screen: Each dialog is controlled by one or more screens.

• GUI status: Each screen has GUI status.

• ABAP Program: Each screen and GUI status in the R/3 system belongs to one ABAP program.

• Screen Flow Logic:
  . PBO: Before the screen is displayed
  . PAI: After a user action on the screen
  . POH: when F1
  . POV: When F4

• Dynpro: A screen with its Flow logic is called a Dynpro.

• ABAP Module Pool :  On a PBO or PAI event a Dynpro calls an ABAP dialog program.

Screen Flow Logic定义了在screen上的各种事件，而Dynpro定义了这个Screen和各种事件。而 ABAP MODULE POOL会处理这些event, 在每次事件时调用一个ABAP program。

ALV Report:

是为了更加方便地打印Table。其中包含了很多的模块可以使用。