VDF-GUIdance - How-To's

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Retrieve lost objects
A tabpage in VDF sometimes looses one or more of its objects. This usually happens after a user clears the entire view. This document describes how to redisplay those lost objects.
Date Created: 20/09/1999		Author: Wil van Antwerpen
Last Update: 03/11/2001		Company: Antwise Solutions

Retain in VDF
Do you remember the item_option "retain" from console mode DataFlex? This is no longer a supported technique in VDF, until now! This white paper describes how you can still make use of the retain field_option in VDF (DD_RETAIN) by adding a few lines of code to your subclass structure.
Date Created: 27/10/2000		Author: Peter Bosch
Last Update: 27/10/2000		Company: info trans Logistik Systems GmbH

VDF running as a Windows NT Service
This document explains step by step how to set up a Windows NT machine so that it is able to run a VDF application as an NT service. This means that the application will automatically run in the background when the computer is booted. The VDF application will even run without a logon.
Date Created: 20/09/1999		Author: Frank G. Vandervelpen
Last Update: 20/09/1999		Company: Velpe Development bvba

Logon keyboard layout
This document explains how to change keyboard layout at logon. An example might be changing to a non-US format.
Date Created: 19/01/1999		Author: Frank G. Vandervelpen
Last Update: 19/01/1999		Company: Velpe Development bvba

Basic TCP-IP in a Word
Some very basic TCP-IP documentation
Date Created: 20/09/1999		Author: Frank G. Vandervelpen
Last Update: 20/09/1999		Company: Velpe Development bvba

MS SBS Limitations
Limitations of Microsoft's Small Business Server
Date Created: 20/09/1999		Author: Frank G. Vandervelpen
Last Update: 20/09/1999		Company: Velpe Development bvba

Explanation regarding oppertunistic locking
An explanation of what really happens with oppertunistic locking
Date Created: 27/09/1999		Author: Frank G. Vandervelpen
Last Update: 27/09/1999		Company: Velpe Development bvba

Write a DWord to the registry
Normally if you write a value to the registry, it will be a string value. This document tells you how to write a DWord value
Date Created: 20/09/1999		Author: Frank G. Vandervelpen
Last Update: 20/09/1999		Company: Velpe Development bvba

Create a header-detail construction
Frank has written some general guidelines on creating a basic header-detail construction in VDF
Date Created: 13/09/1999		Author: Frank G. Vandervelpen
Last Update: 13/09/1999		Company: Velpe Development bvba

Multi-homed system in MS SQL Server
This white paper describes a way to tackle the problem that arises when you want to convert a multi-homed DataFlex database to MS SQL Server. By multi-homed we mean a database with shared datafiles in one directory and specific company-related datafiles in their own seperate directory
Date Created: 17/11/1999		Author: Frank G. Vandervelpen
Last Update: 17/11/1999		Company: Velpe Development bvba

Migrating 2.3 code to DF3.1
This white paper describes some of the problems that you can expect to see if you migrate your code from DataFlex release 2.3 to DataFlex 3.1
Date Created: 16/02/2000		Author: Frank G. Vandervelpen
Last Update: 19/08/2002		Company: Velpe Development bvba

Create autologon in Windows NT
How to have your Windows NT station automatically log in with a default username and password.
Date Created: 20/09/1999		Author: Wil van Antwerpen
Last Update: 20/09/1999		Company: Antwise Solutions

Date masking problems
There are some serious problems when using date masks in vdf.
Date Created: 03/11/2001		Author: Wil van Antwerpen
Last Update: 03/11/2001		Company: Antwise Solutions

Panel gets covered by windows taskbar
This article explains how to fix the problem that can occur if you have a view with a dbform object and a selection list near the bottom of the screen. Popping up the selection list will locate the panel in a way that the buttons are underneath the windows taskbar. This only applies to VDF4/VDF5/VDF6. This behaviour is fixed in VDF7.
Date Created: 09/03/2000		Author: Wil van Antwerpen
Last Update: 09/03/2000		Company: Antwise Solutions

The dbList class unmystified		Download (Size: 127 KB)
This white paper is about the inner workings of the dbList class. Understanding what happens when you press a button that invokes a lookup can help in customizing this class. An online version of the paper is also available.
Date Created: 04/07/2000		Author: Wil van Antwerpen
Last Update: 04/07/2000		Company: Antwise Solutions

Prevent Status Panels losing the focus
The status panel used in BPOs and Winprint will lose its focus when switching to other applications and back. The result is that the application appears to have locked up while it is in fact still running the report or business code. This describes a fix for the problem.
Date Created: 03/10/1999		Author: Geoff Furlong
Last Update: 20/10/1999		Company: MSG Business Systems Ltd.

How to use Microsoft Agent inside VDF applications		Download (Size: 7 KB)
Here is an IDE compatible view that shows how to use the class "cAGENT" generated by FlexCOM to integrate MSAGENTS inside your VDF applications. The view was built while testing all of the MSAgents functions, so please don't comment about the layout of the view, it's only for testing purposes. Please read more before you start using it....
Date Created: 01/08/2002		Author: Franco Spinella
Last Update: 01/08/2002		Company: DATAFLEX SERVICE ITALIA SRL

Creating an NT service for a VDF program		Download (Size: 54 KB)
NT services are something that I've had extensive experience with, on both NT-4 and Windows 2000. This article is a complete guide, including code, to installing and running a VDF program as a service. The "code" is a scheduler that once the service is running, kicks off a program at a required time or periodically throughout the day.
Date Created: 18/08/2002		Author: Bob Worsley
Last Update: 18/08/2002		Company:

Citrix and Visual DataFlex
A paper about Citrix Metaframe and how to use it with Visual DataFlex.
Date Created: 12/08/1999		Author: Filip Huwaert
Last Update: 12/08/1999		Company: Soft-Naert

Migrate legacy process code for use in a BPO		Download (Size: 12 KB)
This paper discusses several different ways on how to migrate your old procedural process code to a BPO. Examples are included
Date Created: 15/10/1999		Author: Dan Walsh
Last Update: 15/10/1999		Company: Legal Software Development

Creating a multilingual application		Download (Size: 80 KB)
The zip-file contains a Word97 document and a password package on how I implemented a top level function in VDF for multi-language changes for ALL visual objects. The database fields label naming is performed by using the method explained in the final chapter of the "Mastering Visual Dataflex" book (not published in here). If these 2 methods are adopted a full language translation facility can be included in ALL your VDF applications, with very little code.
Date Created: 20/10/1999		Author: Peter Mustoe
Last Update: 20/10/1999		Company: FocusTree Ltd

Comparing padded strings
Comparing strings padded with spaces in DataFlex might not exactly work as you would have expected as it is a little bit different from other programming languages. You have to be aware that comparing 'abcd' to 'abcd ' always results to a (True) condition
Date Created: 13/11/2002		Author: Wil van Antwerpen
Last Update: 13/11/2002		Company: Antwise Solutions

IDE Insights Part 1 - Component Code Markers		Download (Size: 6 KB)
The IDE's Visual Designer maintains a set of special markers inside the source code of each component file. These markers are parsed whenever a component is opened, and re-generated when the component is written. This paper presents a description of each special marker...
Date Created: 15/07/2003		Author: John van Houten
Last Update: 15/07/2003		Company: Data Access Worldwide

Dialog Callback		Download (Size: 5 KB)
This paper explains how you can write your own class based on callback logic. The discussed example talks about implementing a callback for a dialog, but you could use this same technique anywhere. It is a very nice explanation of how callbacks work in VDF.
Date Created: 17/07/2003		Author: Bob Worsley
Last Update: 17/07/2003		Company:

Scroll and TabPage samples		Download (Size: 93 KB)
These are the scroll and tabpage examples which Tony showed at the 2003 Meet Me In St. Louis conference. They are neat examples on - having a dbView that automatically scrolls to the activated forms - managing tabpages, howto reorder them dynamically or how-to hide a page dynamically
Date Created: 14/10/2003		Author: Tony Mackay (Anasazi Software Inc.)
Last Update: 14/10/2003		Company: Anasazi Software Inc.

Decimal Separator problems
On some computers the decimal separator on the numerical keypad doesn't seem to respect the regional settings of your language. As an example for dutch the decimal separator is a comma (",") whereas for the US this is a dot (".") In certain conditions, if you try to use the decimal separator key in a numerical field, pressing the key generates an errorbeep instead of the comma.
Date Created: 27/02/2004		Author: Wil van Antwerpen
Last Update: 28/02/2004		Company: Antwise Solutions

Crystal XI Runtime Installer		Download (Size: 135 KB)
Creating a runtime installer for Crystal XI using merge modules.
Date Created: 27/11/2005		Author: Peter van Mil
Last Update: 27/11/2005		Company:

Ping an ipaddress		Download (Size: 13 KB)
Package to ping an ipaddress.
Date Created: 02/06/2006		Author: Allan Kim Eriksen
Last Update: 02/06/2006		Company: NordTeam Gruppen ApS

cCSVWinprint2		Download (Size: 26 KB)
The Winprint II classes are great, but sometimes you want to extend them a little on customer request. Here Bob shows us how you can easily extend a Winprint II report to not only be able to print preview and print, but also export to a CSV file.
Date Created: 02/09/2008		Author: Bob Worsley
Last Update: 09/05/2009		Company:

Another Fusion Charts		Download (Size: 841 KB)
Hi This is Modified order entry with "FusionChartsFree" based on Pepe Guimaraes example thanks for Pepe Guimaraes and Benito Fernandez This application has been tested with Visual DataFlex 14.1 and 15.1 The charts are based on the free controls from: http://www.fusioncharts.com Regards
Date Created: 29/11/2009		Author: Ali Abu-Feilat
Last Update: 03/12/2009		Company:

Datetime compiler problems with long strings
This article discusses the problem your compiler has with long strings in expressions and general datetime functions.
Date Created: 12/03/2010		Author: Wil van Antwerpen
Last Update: 12/03/2010		Company: Antwise Solutions