Programming Archives - Comeau Software Solutions

Custom User Controls and Events in C#

October 22, 2018July 13, 2026 Andrew Comeau

One of the interesting features of C# is the ability to add custom user controls to your forms. If you have some specific functionality centered around a group of form controls that you use repeatedly, you can save it as a custom control in a class library and then add it to other applications. This…

C#, Programming

Using JavaScript with ASP.NET

August 8, 2018April 23, 2024 Andrew Comeau

Why Use JavaScript?

There are a few technologies that you must be comfortable with if you want to do any serious web development. HTML for content, CSS for formatting and JavaScript for dynamic programming are recognized as the three foundation skills that any good web designer needs.

ASP.NET programmers might be tempted to do away with the last item given that .NET code can do virtually anything when combined with HTML and CSS but JavaScript is still very important and the reason lies in the different domains in which each language operates.

Programming, Web Design

My Virtual Vacation and Free Stuff

June 16, 2018March 29, 2024 Andrew Comeau

Summer vacation has mercifully arrived for me and my students. Unlike many teachers, I’m at the school through most of the Summer. My students get three weeks off – I get one week followed by a couple weeks of what will essentially be teacher workdays. Judging from the sympathetic looks I was getting from other staff members and the sudden, dramatic drop-off in attendance of my classes, I’m thinking the break didn’t come a moment too soon.

Programming, Resources

How to Convert Between Roman and Arabic Numerals in C#

March 31, 2018March 29, 2024 Andrew Comeau

The Challenge

My latest challenge to my database programming students was to create a C# class that would perform various number conversions, starting with Arabic numbers (0 to 3999) to Roman numerals and vice versa.

I required that all public functions in the class needed to be declared as static, so that they could be called from outside the class without having to create a new instance. Also, the class was to be completely portable; it must not use any functions such as message boxes that would prevent them from copying the entire class into any other type of project and referencing it. Of course, all code must also have error handling and commenting.

My students came up with various solutions and I think some had more help from StackOverflow than others. I know that one of them learned the hard way not to search for “XXX” on Google.

One popular strategy was to use the C# Dictionary class to hold the Roman characters and their equivalents. I don’t always get around to writing up my own solutions to these challenges before I assign them, so I happily swiped that strategy for my own code which was otherwise written from scratch. I ended up using the SortedDictionary class instead.

C#, Programming

How to Create Lookup Fields in C#

March 8, 2018November 9, 2022 Andrew Comeau

I started my (more or less) serious database development training many years ago in Microsoft Access. One of my favorite controls was the Combo Box, a nice little drop-down field that enabled the user to select one of many values but collapsed down onto a single line. The Combo Box control in Access was very configurable and one of the nice features was that you could display one value while actually saving another value to the field the control was bound to. For example, you could display the Customer Name while saving the associated CustomerID that the database would use to reference the customer record.

C# also has a Combo Box control that can do much the same thing but offers a lot more options through code. The .NET version maintains a collection of objects, any kind of objects, and displays whatever text is presented by the object’s ToString() method. The code can then use any other property of the object to carry out operations in the background.

Programming

How to Retrieve Data from SQL Server into C#

March 7, 2018August 2, 2026 Andrew Comeau

The .NET framework has a few different automated methods for managing connections to SQL Server and other databases. The framework has been around since 2003 and various versions have introduced new, improved data management tools while maintaining the old ones for backward compatibility. It’s still possible, however to retrieve data from SQL Server and other…

Programming

How to Convert Between Decimal and Binary in T-SQL

February 21, 2018March 29, 2024 Andrew Comeau

For the past six months, I’ve been teaching night classes in database programming and my students are just about ready to take Microsoft’s 98-364 exam. Now, we’re transitioning over to C# programming for the next phase of the program but I have to keep their SQL skills fresh for the exam. Tonight, it was time to teach them to understand the binary number system. I dropped some hints on it a couple of months back to brace them but now it was time to get it done with once and for all.

Then, as I like to do with this class, I came up with a lesson plan that would incorporate the best of both subjects …

Programming, SQL

Primes in the Key of C#

December 21, 2016July 13, 2026 Andrew Comeau

Yes, prime numbers are a go-to challenge for me that I’ve been casually playing with since my earliest programming days. I’m not alone; prime numbers are important and popular enough that there’s an entire distributed computing project dedicated to finding the highest Mersenne Prime number (primes such as 31 and 127 that are one less than a power of 2). A decent grounding in math is also important for programmers and prime number algorithms are a much better programming exercise than “Hello, World”.

That’s why, during a holiday trip to a local Barnes & Noble, I was looking through their collection of quick and shallow knowledge books (“100 Factoids That Will Make You Sound Knowledgeable …” ) and found one called Math Squared: 100 Concepts You Should Know. I wasn’t expecting a degree out of this small, 256-page book but it’s been awhile since math class, I thought it might give me some good ideas for programming exercises and I like the feel and smell of new books.

Read More “Primes in the Key of C#” »

C#, Programming

My First Steps with Python – Prime Numbers

November 27, 2016July 13, 2026 Andrew Comeau 1 Comment

I recently started studying the Python programming language. I’m getting ready for a new programming-related position next year and one of my colleagues suggested using Python as part of it. I’ve heard of Python more and more over the past several years and I figured now would be as good a time as any to finally learn it.

I can definitely recommend Udemy’s Complete Python Bootcamp by Jose Portilla. This course is written for complete programming beginners and does an excellent job of introducing the fundamentals and guiding the student through various programming concepts. It’s probably more basic than I actually need but it never hurts to go back to school.

Programming

Calculated Fields in CiviCRM

June 14, 2016December 27, 2022 Andrew Comeau 2 Comments

One of CiviCRM’s strengths is the ability to add custom fields to hold specific information about your contacts. One thing it doesn’t offer (yet) is a calculated field type that will present the results of calculations of other fields. While calculated fields are generally discouraged in relational database design, they are sometimes necessary within a user interface. One suggested method is to add custom code hooks within CiviCRM’s PHP code but as a database guy, I decided on a back-end solution.

Database Design, Programming, SQL