Validation of input elements and Form Closing

One of very often questions ask by WinForms developers is “How to make sure that if Form is Closing, no validation occurs in contained controls”?

For reference, validating input is rather straightforward:

1. Add ErrorProvider to Form
2. For control in question, add handlers for Validating and Validated events:


        private void tbFixPath_Validating(object sender, CancelEventArgs e)
        {
            if (!ControlValidated(tbFixPath.Text))
            {
                // Cancel the event and select the text to be corrected by the user.
                e.Cancel = true;
                tbFixPath.Select(0, tbFixPath.Text.Length);

                // Set the ErrorProvider error with the text to display. 
                this.errorProvider1.SetError(tbFixPath, 
                   "Sorry, something went wrong during validation. Please check.");
            }
        }

        private void tbFixPath_Validated(object sender, EventArgs e)
        {
                // After successful validation, clear error message.
                errorProvider1.SetError(tbFixPath, "");
        }

3. Everything is fine, until user tries to close form where some input elements are not validated – closing will fail. In order to prevent this, if you are absolutely sure that you want to close such form, just add:


        private void MainForm_FormClosing(object sender, FormClosingEventArgs e)
        {
                e.Cancel = false;
        }

so that no cancellation of closing event will occur.

I know that this is basic 🙂 but after I was ask for 10th time in 6 months, I figured that is better to note this somewhere 🙂

Firebird reaches 2.0 milestone

Firebird 2.0

Databases are very important in my area of work; as a simple storage (but rarely), as a smart relational actor in the game or even as replacement for application server, holding mass of business logic rules.

There are more and more very free and very powerful databases on database market. Some are completely free, and some are “entry” models for big guys. Whatever reasons are, they make developer life much, much easier.

One of my favorite free databases is Firebird – and it reached very important milestone: version 2.0. There is long list of enhancements, but to mention just some:

  • Table size is no longer limited to 30 Gb
  • Password encryption now uses a more secure password hash calculation algorithm (SHA-1), encryption becomes entirely server-based and password login is now required from any remote client
  • new interface for plugging in international character sets, including enhanced Unicode support, along with a number of new and corrected collations

Download link: http://www.firebirdsql.org/index.php?op=files&id=engine_200

Let me mention other favorites:

Microsoft

MS SQL Server Express 2005 along with free management tool: SQL Server Management Studio Express – fast and sleek combination for rapid development under .Net 2.0 environment. There are of course limitations, but for most small and middle project this will work just fine.

Also, if you are using older version of SQL 2000 or lite version called MSDE please consider migrating to sQL 2005 – SQL 2000 family won’t be supported on Vista.

Oracle

Oracle Database 10g Express Edition – lite version of “big” Oracle 10g. Perfect companion is Quests’s TOAD Free.

Welcome to yet another blog of mine

Welcome on my first English blog.

I am blogging more than two years on my Serbian blog and that is blog about general technical subjects which are interesting for wider audience. More details about myself you have here and in my resume.

Idea of this blog is to be highly technical and to deal with .Net, Asp.Net, Databases, Web sites, programming in general.

Hope that won’t be boring and that you will find interesting and useful stuff for you.

Once more, welcome on my english blog and thanks for reading 🙂

My Programs

I will use this page to present some small utilities, emerged from daily need to solve some small or not so small problems.

Create Empty File

Marantz DV4100 DVD Utility with very suggestive name 😉 was created when I found out (by slow trial and error method) that my stupid DVD player Marantz DV 4100 (picture), brilliant in all other areas, won’t play burned DVD disks if those disks are not filled up to the end, all 4.7GB – it seems that it dislikes color of not burned part of the disk.

Solution was obvious: make program for creation of the empty (zero filled) files of arbitrary size and then burn them somewhere on the DVD video disk, outside AUDIO_TS / VIDEO_TS folders.

Prerequisites: .Net framework 1.1 or newer should be installed on machine.
Program type: Console (run it from CMD window)
Download: CreateEmptyFile.exe: EXE file, 20kb
Examples:
CreateEmptyFile.Exe  Fileof100b.bin  100
CreateEmptyFile.Exe  Fileof100Kb.bin 100K
CreateEmptyFile.Exe  Fileof100Mb.bin 100M
CreateEmptyFile.Exe  Fileof100GB.bin 100G

Allowed Suffixes: K (* 1024), M (* 1048576) and G (* 1073741824)

LoanCalculator for Siemens SK65

Loan Calculator for Siemens SK65 Recently, I became owner of the nice, heavy and elegant phone, Siemens SK65.

SK65 have lot of memory (64 Mb from which 35Mb is available to user), great PIM part (Personal Information Manager)
which can be synchronized with Microsoft Outlook and good menu system. It’s turn out to be great replacement for old
Handspring Visor Deluxe, Palm compatible device.

What I missed on new platform are small utility programs for everyday tasks. Luckily, SK65 supports Java for mobile devices – Java 2 Platform, Micro Edition (J2ME) and I managed to find replacement for most Palm utilities in the freeware or open source part of J2ME world except one small program: Loan Calculator.

Given the fact that I did not learn new platform / language for quite while, this was good opportunity for me; result of that new challenge is here: LoanCalculator, J2ME (CLCD 1.1 i MIDP 2.0), utility which for given Loan Amount, Interest Rate and Loan period calculates Monthly Payment, Total Payment and Total Interest.

Program is tested using SK65 emulator as well in the phone itself; it should work on all Siemens Series 65 phones and on other J2ME enabled phones which support CLCD 1.1 and MIDP 2.0.

Used in development:

Prerequisites: Mobile phone with Java support (J2ME, CLCD 1.1 i MIDP 2.0)
Program type: Utility, for calculating Monthly Payment, Total Payment and Total Interest.
Download: LoanCalculator.zip: ZIP with .jar and .jad file, 5kb

Dejan D. Vesić – Curriculum Vitae (Resume)

Personal Details:

Name: Dejan Vesić
Date of birth: 23. April 1969

E-mail:
Web site: http://www.vesic.org/english/
LinkedIn profile: http://www.linkedin.com/in/dejanvesic

Microsoft Certified ProfessionalMicrosoft Certified Application Developer for .Net

Summary:

Highly skilled, very efficient, organized and focused senior programmer and project manager.

Specialist for the E-commerce solutions based on Microsoft Web technologies on top of MS SQL or Oracle database servers.

years of experience. Strong in .Net (C# / ASP.NET), XML, JavaScript, DHTML, Database design, PL/SQL, T-SQL, ADO / ADO.NET, scripting and shell languages (Awk, CMD, 4Dos / 4NT).

Objective:

To utilize my technical and management background as a project manager / technical team lead / senior software developer or principal consultant. Particularly interested in .Net projects.

Other projects:

July 2009: Kolegijum – http://www.kolegijum.com/
  • Usability consulting
  • Coding
  • Maintenance
March 2009: Vegamedia – http://www.vegamedia.rs/
  • Usability consulting
  • Coding
  • Maintenance
Oct 2006 M2E Construction and Consulting site (Miami Construction & Consulting Engineers Company) – http://www.m2econsulting.com/
Leading development of site:

  • Taking requirement from client
  • Synchronizing work of Flash and Html developer
  • Doing initial check-up and Q&A both on Flash and Html portion of site
  • Giving first support & maintenance (update of site)
Sep 2003 – Nov 2004 eCash – ASP.NET Front end
Was reponsible for complete architecture and implementation of the selected solution.

  • Completely built on ASP.NET 1.1
  • Multilanguage enabled (changing language on the fly)
  • Processing of IFX (Interactive Financial eXchange) messages (both standard and custom) via XML/XSD
  • Presentation layer built on CSS 1.1/XHTML; can be consumed both with desktop browsers as well as from mobile devices (Credits for this part: Studio Aplus)

Work History:

May 2010 – present GTECH Belgrade branch – CEO (Chief Executive Officer) in 150+ people company
  • Managing strong development company
  • Team Building
  • Interviewing for technical positions in company
  • Evaluating, giving recommendations and selecting software platforms for development
  • Guidelines in software development
Jul 2007 – May 2010 GTECH Belgrade branch – CTO (Chief Technology Officer) in 120+ people company
  • Evaluating, giving recommendations and selecting software platforms for development
  • Guidelines in software development
  • Interviewing for technical positions in company
  • Team Building & Management
Aug 1999 – Jun 2007 Finsoft Belgrade
  • from May 2004: CTO (Chief Technology Officer) – in charge for development of company’s main product – MarginMaker™,
    first class platform for fixed odds betting. Some of the responsibilities: business analysis, making specifications, tracking development progress, maintaining Q&A procedures, controlling deployment & release processes, interviewing
    candidates for development positions.
  • from Apr 2002: Team leader of Web team – completely responsible for development, support and maintenance of site http://www.stanjames.com (ASP over Oracle database,
    .Net Web Services, Awk for log processing…)
  • from Mar 2000: Lead Web programmer – developed first version of the site http://www.sportingodds.com, ASP over Oracle database.
  • from Aug 1999: Database developer – worked on PL/SQL procedures (Oracle) for http://www.sportingindex.com, spread betting system.
Nov 1998 – Jul 1999 Freelancer
Various projects; static web sites, dynamic web sites (ASP / Access or MS SQL as database foundation).
Feb 1997 – Oct 1998 Industrial Computer Control Electronics, Belgrade
  • Analyst programmer responsible for the design and implementation of applications for data acquisition and processing data of automated industrial processes. Tools used were PowerBuilder 5.0 and FoxPro 2.6 for Dos.
  • Web programmer responsible for developing ways to access corporate database over HTTP, using DHTML & JavaScript and IDC.
Jun 1996 – Jan 1997 Freelancer
  • Developing large Informational System for one big company in Belgrade. This was done in Power Builder 5.0 for client side, Sybase Sqlanywhere 5.5 as database engine and Novell NetWare 4.11 as network server. Supporting routines were developed in Delphi 1.0 & 3.0
Sep 1995 – May 1996 “TEHNOKOMERC”, Aranđelovac
  • Developing specific applications for business tasks and for everyday use. Incorporating Microsoft Office solutions into local Intranet.
  • Setting up Windows Peer to Peer Network, starting with two, ending with six stations connected in Intranet.
Jun 1994 – Aug 1995 “GP Gradnja Jovanović”, Aranđelovac

IT manager responsible for network, applications and hardware:

  • Author of complete IT solution – covering trade part, storing and retrieving documents, and Clipper applications for every segment of business.
  • Setting up hardware layout for network – LAN cards, 10BaseT cables, and one remote station over leased line.
  • Setting NetWare 3.11 server and administering it. Solutions for Fax over network, and for mail system under DOS
Nov 1993 – May 1994 “Beoizlog”, Belgrade

Contractor for desktop applications for accounting and reporting

  • Applications built with Clipper 5.03, using my own libraries for User Interface, logging, auditing and printing

Newspaper articles, recensions and books:

Education and qualifications:

Dec 2003 Microsoft Certified Application Developer For Microsoft .NET

Exams:

  • Developing XML Web Services and Server Components with Microsoft Visual C# .NET and the Microsoft .NET Framework
  • Designing and Implementing Databases with Microsoft® SQL Server™ 2000 Enterprise Edition
May 2003 Microsoft Certified Professional

Exam:

  • Developing and Implementing Web Applications with Microsoft® Visual C#™ .NET and Microsoft® Visual Studio® .NET
1989 – 2006 Mathematical Faculty, Computer Science division, University of Belgrade
Bachelor of Science in Computer Science (average mark of 8.77 out of 10). This is equivalent to a first degree in UK.
1984 – 1988 Gymnasium (high school), Aranđelovac
One of the top students – average mark was 5.0 out of 5.

About Me


Dejan D. Vesić

Dejan Vesic, .Net/C# specialist
e-mail:

Details …

Date of birth: 23. April 1969, Wednesday
Age:
Zodiac: Taurus/Gemini

Interests:

Profession – Programmer:

  • More than years of professional programming
  • Member of the Gutu community (please click here for my profile)

MS Visual Studio Express

http://msdn.microsoft.com/vstudio/express/

Verzija Veličina Licenca Cena
2005 70 – 450 Mb Besplatan

MS Visual Studio Express 2005

U cilju promovisanja nove verzije Visual Studio paketa za razvoj programa (verzija 2005) Microsoft je povukao fenomenalan potez – napravio je Express verzije ovog paketa i čak ih deli besplatno u prvih godinu dana (do novembra 2006.)!

Iako MS reklamira Express verzije kao oslabljenu verziju “velikog” paketa, namenjenje studentima i svima koji žele da se upoznaju sa samim okruženjem i .Net Framework-om 2.0, to su ozbiljni, zaokruženi paketi za razvoj, sa sve SQL Express 2005 bazom podataka.

MS Express ima nekoliko izdanja podeljenih u dve grupe:

  1. Visual Web Developer 2005 Express Edition
    • Podržava i C# i VB.Net kao jezike za razvoj
    • Koristi ASP.NET 2.0 nad .Net Frameworkom 2.0 za Web aplikacije
    • Download ISO slike (449,848 KB)
  2. Grupa za razvoj Windows (“desktop”) aplikacija:

Ako izaberete skidanje ISO slike (slika celog CD-a), pored samog Express paketa dobićete i odgovarajuću biblioteku znanja (MSDN Express) kao i SQL Express 2005 bazu, za razvoj aplikacija nad bazom podataka.

Toplo preporučujem da se po instalaciji paketa registrujete (kada ste u Expressu: Help -> Register Product) i time dobijete registracioni kod kao i razne pogodnosti (250 slika iz Corbis Image Pack-a za vaše programe, preko 100 ikonica u IconBuffet Studio Edition Icon Suite itd).

Da sumiram:

  • Ako skinete, instalirate i registrujete odgovarajući Express paket do novembra 2006. imate pravo na besplatno korišćenje sve dok je paket “živ”.
  • Nema nikakvih ograničenja za distribuciju aplikacija napravljenih ovim paketima.
  • Postoji gomila Starter Kit – gotovih aplikacija koje samo čekaju da ih preuzmete, analizirate / naučite nešto novo ili prilagodite svojim zahtevima.

Update 25.april:

Microsoft je odlučio da Express izdanja budu besplatna bez ograničenja! Detalji: Visual Studio 2005 Express Announcements!

Takođe, obavezno svratite na sajt Coding4Fun.

Update 15.11.2006: Izašao je Visual Studio 2005 Express SP1. Preporučujem da ga skinete i instalirate (za odgovarajuću verziju Express-a koju koristitite):
http://www.microsoft.com/downloads/details.aspx?familyid=7B0B0339-613A-46E6-AB4D-080D4D4A8C4E

Update 01.02.2008: Sada je tekuća verzija Visual Studio 2008 Express – topla preporuka!