Skip to main content

Consoles for Mr.GUI !!!

Learnt something new, a small one but very useful.
Many times I have seen GUI applications accompanied by console windows that show logs or trace information of the application. How do we do that for our application ?

Any GUI application can create its own console window just by calling AllocConsole Win32 API. Actually any process can use that API to allocate a new console. And the application must also learn to be disciplined enough to FreeConsole. Ok, fine. I used that in my small MFC application and was happy to see the console. But I did not see anything displayed on the console. As we know, each process has its own stdin, stdout and stderr. So redirect the console output of your parent application to the console. How do you do that ?

Use the FILE *freopen(const char *path, const char *mode, FILE *stream); API. The freopen function closes the file currently associated with stream and reassigns stream to the file specified by path. By that way, call freopen as follows:-

FILE *fpStdOut = freopen ("CONOUT$", "w", stdout);

This means that I want to reassign the standard console output stdout with the console output of the parent application CONONUT$. So any printf calls will print the characters on the console. Cool !!!

Comments

Post a Comment

Popular posts from this blog

Extension Methods - A Polished C++ Feature !!!

Extension Method is an excellent feature in C# 3.0. It is a mechanism by which new methods can be exposed from an existing type (interface or class) without directly adding the method to the type. Why do we need extension methods anyway ? Ok, that is the big story of lamba and LINQ. But from a conceptual standpoint, the extension methods establish a mechanism to extend the public interface of a type. The compiler is smart enough to make the method a part of the public interface of the type. Yeah, that is what it does, and the intellisense is very cool in making us believe that. It is cleaner and easier (for the library developers and for us programmers even) to add extra functionality (methods) not provided in the type. That is the intent. And we know that was exercised extravagantly in LINQ. The IEnumerable was extended with a whole lot set of methods to aid the LINQ design. Remember the Where, Select etc methods on IEnumerable. An example code snippet is worth a thousand ...
7 comments
Read more

Wetting my feet in Android - Seinfeld Calendar

A couple of my colleagues and I huddled up to learn a bit of Android. I think I told you about that a short while back. We developed a very simple application - The Seinfeld Calendar . Seinfeld calendar, or otherwise called the habit calendar, is Seinfeld's productivity secret . The secret of achieving your goal is practising something, whatever your goal is, everyday and make it a habit. And mark it in your calendar each day you practice, and make sure you do not break the chain. Our application helps you keep track of your everyday tasks. Our application does not jog or meditate or quit smoking for you. You have to do your tasks. Our application provides the facility to create tasks for the habits you wish to pursue, which in certain cases like smoking means quitting. And then you mark each day in the calendar if you pursued your task, else you don't mark and break the chain. And no cheating! The application is in very nascent stage and does not provide you (fancy) s...
7 comments
Read more

Android meets .NET !!!

It is always fun for me to program in C# (besides C++). If so, how would I feel if I was able to program for Android in C#? You may be wondering what in the world I am talking about. Android development environment is all Java and open source stuff. How could this Microsoft thing fit onto it? Well, it seems that some clever guys had huddled up and ported Mono for Android , developed .NET libraries for the Android SDK, and also supplemented it with a 'Mono for Android' project template in Visual Studio; and called it mono for android . Thus we end up writing C# code happily for Android. After a bunch of installations , fire up your Visual Studio (2010) and you should be seeing a new project template 'Mono for Android' under C#. Create a new 'Mono for Android' project, which by default comes with an activity - C# code. Modified the orginal code to try starting a new activity from the default one... The project layout for most of the part is...
7 comments
Read more