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I have a windows project that builds and reports no errors but when a press start it doesnt open or run the application and exits

What I have tried:

I have tried to clean the solution but it doesnt solve the problem
Posted
Updated 3-Oct-17 10:26am
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Solution 1

Then you need to look at the code!

Compiling does not mean your code is right! :laugh:
Think of the development process as writing an email: compiling successfully means that you wrote the email in the right language - English, rather than German for example - not that the email contained the message you wanted to send.

So now you enter the second stage of development (in reality it's the fourth or fifth, but you'll come to the earlier stages later): Testing and Debugging.

Start by looking at what it does do, and how that differs from what you wanted. This is important, because it give you information as to why it's doing it. For example, if a program is intended to let the user enter a number and it doubles it and prints the answer, then if the input / output was like this:
Input   Expected output    Actual output
  1            2                 1
  2            4                 4
  3            6                 9
  4            8                16
Then it's fairly obvious that the problem is with the bit which doubles it - it's not adding itself to itself, or multiplying it by 2, it's multiplying it by itself and returning the square of the input.
So with that, you can look at the code and it's obvious that it's somewhere here:
private int Double(int value)
   {
   return value * value;
   }

Once you have an idea what might be going wrong, start using teh debugger to find out why.

Start with Program.cs, and put a breakpoint on the first line of the Main method.
Run your app in the debugger and it should immediately stop at the breakpoint, allowing you to start looking at what is going on.

Think about what each line in the code should do before you execute it, and compare that to what it actually did when you use the "Step over" button to execute each line in turn. Did it do what you expect? If so, move on to the next line.
If not, why not? How does it differ?

This is a skill, and it's one which is well worth developing as it helps you in the real world as well as in development. And like all skills, it only improves by use!
   
Comments
Member 10578733 3-Oct-17 16:51pm
   
Thanks for the advise but i dont think there is a problem with the code because i got the source code from my friend and it was running well with no issues at all
OriginalGriff 3-Oct-17 17:10pm
   
Means nothing: the code is the app, so since the code isn't working, you need to use the debugger to find out why.
We can't do that for you: I can't even see your screen from here, much less reach your keyboard...
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Solution 2

Quote:
when a press start it doesnt open or run the application and exits

No you are able to see fast enough to know what happen or not. All you can know, it is that something have happened because a result is displayed.
There is only 1 way to know what is going on, use the debugger and execute your code line by line.

There is a tool that allow you to see what your code is doing, its name is debugger. It is also a great learning tool because it show you reality and you can see which expectation match reality.
When you don't understand what your code is doing or why it does what it does, the answer is debugger.
Use the debugger to see what your code is doing. Just set a breakpoint and see your code performing, the debugger allow you to execute lines 1 by 1 and to inspect variables as it execute.

Debugger - Wikipedia, the free encyclopedia[^]
Debugging C# Code in Visual Studio - YouTube[^]
The debugger is here to show you what your code is doing and your task is to compare with what it should do.
There is no magic in the debugger, it don't find bugs, it just help you to. When the code don't do what is expected, you are close to a bug.
   
Comments
Member 10578733 3-Oct-17 16:53pm
   
Thanks for the info,let me give it a try

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