The LA Fox Developer

A Newsletter for FoxPro Application Developers in Southern California

Visit our WebSite at: http://www.mesllc.com/lafox.html September 1997

Drag-and-Drop in VFP

David A. Greene, MA, MCSD

Productive Solutions, LLC

Our job as software developers is to build applications that are

useable; not just applications that we think are useable, but

applications that really are useable by normal people. This

involves knowing all the tools available to us, how they work,

and when to use them. Microsoft has built so much into Visual

FoxPro that it will be years before any one of us conquers

everything this language has to offer, so this article came about

as a way to share a few shortcuts about a tool that has likely

been under-implemented in the past.

I had my initial doubts about using drag-and-drop. It was never

clear to me why this was invented when so many other controls

are adequate, but after using it in a few applications it became

clear that users exert more control over the computing environ-

ment when they can both select an item and the action to be

taken using that item. These are subtle user benefits, to be

sure, but drag-and-drop is state of the art and our clients (:r.d

superiors) are simply going to expect it.

The Scenario for this Demo

A System Administrator (with some FoxPro training) can add,

delete, or modify reports (.FRX/. FRT) for a particular system.

There is no telling how many reports may be in the system at a

given time, and users must be able to select whether a report is

sent to the screen or to the printer. Yes, this task can be

accomplished in a number of ways, but, after all, this is a Drag

and Drop demo.

Two tables will be used for this demonstration - a Reports table

with two fields for report Descriptions and for report filenames,

and an Employee table - plagiarized from the Tasmanian

Traders demo that comes with VFP.

In the form above, users are presented with a listbox containing

the report descriptions, two .BMP image objects as drop

targets, and a “Close” button to close the form.

Building Drag-and-Drop

Microsoft gives us two ways to use Drag-and-Drop: Manual

(Con’t, page 3)

In this issue

ActiveX, Part 2

VFP Assistance

Tricks, Tips, etc.

Out and About

by Barry R. Lee

At LA Fox

September 22, 1997,7:30 PM - Bill Anderson. Following a

discussion on the latest “stuff’ from DevCon, Bill will demo

Visual FoxExpress. Please take special note in the change of

date for this meeting. Since our regular meeting (Sept. 15th)

falls during the San Diego DevCon, we’ve re-scheduled. Thanks

to Twila Miller, our treasurer, and a stroke of luck, we’ve been

able to arrange for our regular meeting place at the Torrance

Airport.

October 20, 1997, 7:30 PM - Peter Butterfield. Peter

Butterfield’s Los Angeles consulting firm has built a nation-wide

client list in a dozen business domains. He has been an xbase

consultant so long that he still uses “ctrl+w”. His VFP frame-

work, Butterworks, originated with the beta version VFP 3.0 in

1995, and is now in its third design iteration. Employing the

user interface portion of Butterworks as a case study, he will

discuss some of the issues of the object oriented design

process. Among those topics covered will be the use of visual

object modeling tools, the applicaton of design patterns, the

management of class hierarchies, and, particularly, the non-

visual approach to VFP implementation of object model de-

signs.

Elsewhere

September 14-17, 1997- DevCon. The mother of all FoxPro

Developer Conferences convenes in SanDiego. This is the

eighth almost-annual gathering of FoxPro developers from

around the world. This is where you can gather with the best in

the industry, members of the Microsoft Visual FoxPro product

team, and developers from around the world to learn how to

solve your programming puzzles. Find out how to get it done

(Con’t, page 2)

Page 4

Page 7

Page 8

The September meeting of LA Fox will be

held on Sept. 22, 1997, at 7:30 PM at our

regular meeting place (the Torrance Airport,

3301 Airport Drive, in Torrance). For details

on how to get there, see the map on the back

page.

and much more