Programming DCOM Clients with VB (SAP Library - Tutorial: Communication Interfaces)

Programming DCOM Clients with VB

Task

You create a simple DCOM client application as the user interface for calling a business object that is used to export data from the R/3 system.

In particular, you

use the DCOM Object Builder to generate a DCOM proxy from business object EmployeeAbstract and install it in MTS
write the client application using Visual Basic.

Establish the connection to the R/3 System.
Export the list of employee data.
Use MSFlexGrid Control to display the data from R/3 as a table.

Overview: Unit Objectives

In this unit, you learn how to

use the DCOM Object Builder to generate DCOM proxies from R/3 business objects and install them in MTS
create a simple user interface with Visual Basic for BAPI calls
include the required controls and the generated type library in the project
create local instances of R/3 object types
set connection parameters and establish a connection to the R/3 System
call BAPIs
display R/3 data using the MSFlexGrid Control
assign the essential software components to the four-layer architecture

Prerequisites

Systems

R/3 System with available business objects

Operating systems Windows NT (Service Pack 3) or Windows 95

Installations

RFC SDK of R/3 4.5A is available.

MTS (Microsoft Transaction Server) and Windows Scripting Host are installed on the target machine (proxy server) (NT Option Pack).

Internet Explorer 4.01 (or higher) is installed on the target machine.

OLEDB SDK 1.5 is installed on the target machine (MS Setup).

A development environment for Visual Basic 5.0 is installed on the client machine.

Knowledge and Authorizations

Authorization to log on to the R/3 System

Administrator privileges on the target machine (proxy server)

Basic knowledge of Visual Basic

Basic knowledge of object-oriented programming

You have determined the interface definition of the BAPI using the BAPI Browser or the SAP Assistant, for example, and have successfully called the BAPI itself. Appropriate business data is available in the relevant R/3 System.

Additional Prerequisites

The client application must run on the same machine as MTS.

Alternatively, you can access the MTS components remotely from the client machine. For information on how to configure the client machine for this purpose, see the documentation on the DCOM Object Builder.

How to continue

Architecture

Exercise 1: Generate and Install DCOM Proxies