C # how to judge whether a program code stuck.

The problem is not simple at all. It looks like there is no any practical alternative to debugging, but we have some remote and limited hope for something better.

Let's say we need some definitive automated diagnostics of the infinite loop problem. It can be embedded in the program in question or based on static code analysis, no matter compiled or source code.

Strictly speaking, this is totally impossible. This is proven mathematically and is known in computability theory as the "halting problem". With any kind of code analysis, it is theoretically impossible to predict if some program will ever terminate or not. Please see:
http://en.wikipedia.org/wiki/Computability_theory_%28computer_science%29[^],
http://en.wikipedia.org/wiki/Halting_problem[^].

So, the most general problem formulated as "give me the way to predict if some program can get in an infinite loop or not" is the ill-posed problem and cannot be solved. Nevertheless, there is some hope. If you look at the proof of the theorem, you will see that the idea is this: suppose the algorithm for solving of the halting problem exist; let's name it A. We can design such a program P using A that works the way A fails. So the hopeful question is: can we formulate some very wide practically significant subclass of programs which behavior could be predicted. (Of course you can find many trivial subclasses of programs, for example, programs with no forks, or not loops, etc. Such finding would not have any practically important sense.)

Several years ago I saw just one article telling us that Microsoft started some research in this direction. I never heard about any results so far. So, right now debugging and just using human brain is the only option.

—SA

Both Solution 1 and 2 given are good answers.

The recommended practice in .NET to handle errors or exceptions is to wrap the code within the try block and in case of exception, deal with that exception in the corresponding catch block. Then, to execute any code either in case of non failure or failure of the code within the try block, the finally block can be used. Exception handling is explained here.
http://msdn.microsoft.com/en-us/library/s7fekhdy(v=vs.71).aspx[^]
But, in case of infinite loop, the program will run until any error occurs, which may be very long time, till that time no response may be there even with the try catch block. So, I think it is wise to debug the program and observe whether any infinite loop is being executed. If you are new to debugging it is better to learn debugging and it will be a very good help in writing the program and a real time saver.
In this regard I think the following articles may be helpful
http://www.dotnetperls.com/debugging[^]
Mastering Debugging in Visual Studio 2010 - A Beginner's Guide[^]

Why don't you just step through / debug your program? That should give you a fair idea of what is going on inside your code.

There are tools like WinDbg which could help you trace a deployed application.

Hi,

Just write the logs before and after calling the function (Messagebox is other option).
Another option is to debug your program..