CODEWITHSUNDEEP
c#windowsvisual-studio-2010windows-7console
user1632018
user1632018

Reputation: 2555

Console application closes immediately after opening in visual studio

I am trying to open a console application in visual studio built in C#. As soon as I open it, it closes immediately.

I know windows sets this is a a safety default (atleast I think). How do I fix this?

I know I can compile it and create a shortcut and modify the target so it has the location of the command prompt in it before the applications location. Although the programmer who created this has it generating information into the output of visual studio, so it's imperative that I only open it there.

It happens with most applications and not just in visual studio, just in this case I need it to open in VS 2010. I am using Windows 7.

Upvotes: 4

Views: 11189

Answers (6)

Mike Nakis
Mike Nakis

Reputation: 62130

Here is an approach which involves managed-code-only:

Asking the user to press a key before a console application exits is called "exit-pause" or just "pause".

  • You want to pause if the console window of your console application will automatically close as soon as your console application terminates. This is the case when your console application is launched from a GUI application such as Windows File Explorer.

  • You do not want to pause if the console window is going to stay open after your console application terminates. This is the case when your console application is launched from a pre-existing console window which is running a command prompt. (Pausing in that case would not only be mighty annoying, but also highly problematic, because it would cause stalling of batch files invoking your console application.)

Now, observe the following:

  • When your console application is launched by a GUI application, it receives a brand new empty console window, (which will close as soon as your console application terminates,) so the console cursor in that window starts at (0, 0).

  • When your console application is launched from a pre-existing console window running a command prompt, then some stuff will invariably have already been displayed in that console window, (at the very least, a command prompt like "C:\>",) so the cursor in that window does not start at (0, 0).

Therefore, the following can be used during the startup of your console application to determine whether it should pause:

bool shouldPause = (System.Console.CursorTop | System.Console.CursorLeft) == 0;

However, be careful:

When using this approach, you must make sure that your console application evaluates this expression as the first thing it does in Main(), that is, before printing anything to the console; otherwise this expression will always evaluate to false.

Upvotes: 0

Koray Elbek
Koray Elbek

Reputation: 844

So, according to here

If your process is the only one attached to the console, then the console will be destroyed when your process exits. If there are other processes attached to the console, then the console will continue to exist (because your program won’t be the last one).

And if we adapt the code to C# you would end up something like this:

using System;
using System.Runtime.InteropServices;

namespace CheckIfConsoleWillBeDestroyedAtTheEnd
{
    internal class Program
    {
        private static void Main(string[] args)
        {
            // ...

            if (ConsoleWillBeDestroyedAtTheEnd())
            {
                Console.WriteLine("Press any key to continue . . .");
                Console.ReadKey();
            }
        }

        private static bool ConsoleWillBeDestroyedAtTheEnd()
        {
            var processList = new uint[1];
            var processCount = GetConsoleProcessList(processList, 1);

            return processCount == 1;
        }

        [DllImport("kernel32.dll", SetLastError = true)]
        static extern uint GetConsoleProcessList(uint[] processList, uint processCount);
    }
}

Upvotes: 1

Hans Passant
Hans Passant

Reputation: 942255

This is an ancient problem and has inspired several funny cartoons:

enter image description here

Let's fix it. What you want to do is prompt the user to press the Any key when the console app was started from a shortcut on the desktop, Windows Explorer or Visual Studio. But not when it was started from the command processor running its own console. You can do so with a little pinvoke, you can find out if the process is the sole owner of the console window, like this:

using System;

class Program {
    static void Main(string[] args) {
        Console.WriteLine("Working on it...");
        //...
        Console.WriteLine("Done");
        PressAnyKey();
    }

    private static void PressAnyKey() {
        if (GetConsoleProcessList(new int[2], 2) <= 1) {
            Console.Write("Press any key to continue");
            Console.ReadKey();
        }
    }

    [System.Runtime.InteropServices.DllImport("kernel32.dll")]
    private static extern int GetConsoleProcessList(int[] buffer, int size);
}

Upvotes: 19

d.moncada
d.moncada

Reputation: 17402

You can also run the application by pressing (Ctrl + F5) .. This will allow it to run in 'Release' mode, and by default, you will need to press 'return' to close the window.

Upvotes: 9

LMS
LMS

Reputation: 4217

You need to wait for user input. Use either Console.ReadLine(), Console.Read(), or Console.ReadKey().

Upvotes: 2

Knaģis
Knaģis

Reputation: 21495

Try adding Console.ReadKey(); at the end of Main() method. This is a quick and dirty way of stopping the window from closing by itself.

Upvotes: 2

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