What is better for a student programming in C++ to learn for writing GUI: C# vs QT?

Question

I'm a teacher(instructor) of CS in the university. The course is based on Cormen and Knuth and students program algorithms in C++. But sometimes it is good to show how an algorithm works or just a result of task through GUI. Also in my opinion it's very imporant to be able to write full programs. They will have courses concerning GUI but a three years, later, in fact, before graduatuion. I think that they should be able to write simple GUI applications earlier. So I want to teach them it.

How do you think, what is more useful for them to learn: programming GUI with QT or writing GUI in C# and calling unmanaged C++ library?

Update.

For developing C++ applications students use MS Visual studio, so C# is already installed. But QT AFAIK also can be integrated into VS.

I have following pros of C# (some were suggested there in answers):

• The need to make an additional layer. It's more work, but it forces to explicitly specify contract between GUI and processing data. The border between GUI and algorithms becomes very clear.
• It's more popular among employers. At list, in Russia where we live. It's rather common to write performance-critical algorithms in C++ and PInvoke it from well-looking C# application/ASP.Net website. Maybe it is not so widespread in the world but in Russia Windows is very popular, especially in companies and corporations due to some reasons, so most of b2b applications are Windows applications.
• Rapid development. It's much quicker to code in .Net then in C++ due to meny reasons.

And the con is that it's a new language with own specific for students. And the mess with invoking calls to library.

Answer 1

Qt -- P/Invoke to use a C++ library from C# adds a whole 'nother layer of nonsense you don't want to even think about. If you were going to use .NET, it might be worth considering using C++/CLI, which linking managed and native code much easier.

Answer 2

It is better to familiarize students with Qt, as Qt is actually C++. C# is a completely different beast, and if you use C#, you will very likely get your students confused about what things are Microsoft- or C#-specific vs. what is actually defined in the ISO C++ standard, whereas this will be more obvious with just C++. Moreover, Qt and C++ are portable, so your students who are using Mac OS X or Linux will thank you for choosing a cross-platform framework (Qt also works on Windows); whereas, if you use C#, you will force your students to use Windows (yes, there is Mono, but it doesn't work nearly as well as Qt does across platforms).

You might also be interested in using my C++ Project Template which provides sufficient infrastructure for devleoping a Qt GUI application in C++ using CMake, and has been tested and verified to work under Mac OS X and Ubuntu Linux (and, if I get feedback on Windows, I will ensure it works there too). The template includes code that brings up a "Hello World" GUI in Qt when run with the "--gui" commandline option.

Answer 3

I would recommend Qt simply because it is C++, and not C#.

Interfacing between C++ and C# can be messy, and in my opinion would distract students from the object of the exercise (the algorithms, as you said).

Answer 4

I would use C# for the GUI stuff.

There are way more C# jobs out there than C++ using Qt, so why not prepare them for what they are most likely to encounter after they graduate?

One problem I have seen with academia quite often is not teaching what is used in the real world. Sure, all that other stuff is cool, and I personally like it. Experience of real world use after school would be my priority though.

Also, I don't think asking a bunch of programmers is generally the best source of advice on this subject. I would look at what technologies most companies are hiring for in your location, very likely for most desktop GUI stuff it will be .NET or Java.

Answer 5

Here's a wild idea, (re)write the algorithm in C# for the GUI app. This serves too purposes, 1) it neatly sidesteps the whole mucking with P/Invoke, C++/CLI or COM just to draw some pretty pictures and 2) unlike using Qt it gives you the opportunity to emphasize the distinctions between an algorithm, a program and a programming language.

Answer 6

writing GUI in C# and calling unmanaged C++ library because VS is a good starting IDE and .NET is the most comprehensive set of libraries available. This assumes your students have access to Windows computers. If they are on linux, QT would be the way to go.

Answer 7

I don't think it makes any sense to start creating C++/C# unmanaged/managed hybrid applications here.

For teaching it will certainly be easier if the students don't have to learn a new programming language for the Gui. Also interfacing between managed and unmanaged code and the different types in the different languages will complicate things unnecessarily. Much time and effort will be wasted on these topics, not helping anybody to learn the algorithms that are the topic of the course.

Also for "real life" usefulness I think it's clear that only very few projects will use a C++/C# hybrid. If you do your GUI in C# you will also do the logic behind it in that language. I don't see what would be gained from creating the GUI of a C++ application in C#.