Console.WriteLine isn't working anymore in VS2012

Question

All of a sudden my Console.WriteLine isn't displaying anything anymore in the "Output" window. Debug.WriteLine does work though. I already checked with right-click on the "Output" window that all messages are still checked. I also went through the settings but couldn't find anything.

I ran out of idea's, does anyone have an idea on how to solve this?

@Sachin thanks for mentioning a topic without any solutions. Try reading my problem for once. — The Cookies Dog, Jun 08 '13 at 08:55
@Thousand No, a WPF application. It always worked fine until yesterday. — The Cookies Dog, Jun 08 '13 at 08:56
Unfortunately, nothing. It didn't work anymore all of a sudden. — The Cookies Dog, Jun 08 '13 at 09:02
@newStackExchangeInstance Yes, I'm sure. The only thing I can imagine is doing some wrong key press, but I couldn't find any key combination that could possibily alter Console.WriteLine output. — The Cookies Dog, Jun 08 '13 at 09:06
At the top of your `Output` window there's a droplist called `Show output from` - is it definitely set to `Debug`? Also, did you install or update any add-ins lately? — Matthew Watson, Jun 08 '13 at 09:09
Even a WPF application can be compiled as console application. Check in project properties - application - next to destination framework (don't know the exact title in english VS version): is this set to Windows app or Console app? Also, have you restarted VS? — JeffRSon, Jun 08 '13 at 09:29
Yes, restarted VS a couple of times already (and Windows). It's set to Window app, not Console app. The show output from is at Debug and not Build/Build order. — The Cookies Dog, Jun 08 '13 at 09:38
Try setting it to Console app and check if the output appears in the additional window. Also, if you've (hopefully) working under version control, try the version of the day before. — JeffRSon, Jun 08 '13 at 09:40
Have you, somehow, redirected stdout? Or free'd the console (called WinApi FreeConsole) — JeffRSon, Jun 08 '13 at 09:58
Another thoughts: check whether Console.WriteLine works the intended way from app.xaml.cs (constructor) or how it behaves in a new project. — JeffRSon, Jun 08 '13 at 11:05

score 3 · Accepted Answer · answered Jun 08 '13 at 10:45

Getting output from Console.Write/Line() to appear in the VS Output window is a non-trivial feature. it requires debugging with the "Visual Studio Hosting Process". You'll see it back in both your build directory and TaskMgr.exe's Processes tab, it has the same name as your project but ends with "vshost.exe".

A fair amount of invisible magic happens inside the hosting process. It is a custom host for the CLR that gives the CLR different behavior from the one you normally run with. It is very poorly documented, the primary reason for its existence appears to be related to security. But one goody it takes care of is being able to redirect output written with Console.Write to the Output window.

Project + Properties, Debug tab, verify that the "Enable the Visual Studio hosting process" option is still ticked.

This is otherwise perhaps a fortunate mishap. You really ought to use Debug.Print() or Debug.Write/Line() in your code to generate diagnostic strings. It uses an entirely different way to generate output, one that doesn't depend on the hosting process. It uses the default TraceListener, one that talks to the debugger directly. The underlying winapi call is OutputDebugString(). The best features of the Debug class is that the calls you make in your code are automatically removed when you build the Release version of your program. So they don't take any overhead anymore, not the case for Console.Write. And that you can reconfigure trace listeners to generate output to, for example, a file.

He wrote in the comments above that `Console.WriteLine` doesn't appear in a real console as well. That, at least, should work without any VS magic. — JeffRSon, Jun 08 '13 at 11:03
He doesn't have a "real console" in a WPF app. This question was asked in a somewhat clumsy way, also the reason it is getting closed as a dup I'd guess. As far as I can tell it is not a dup. — Hans Passant, Jun 08 '13 at 12:19
Thanks, that was also checked. I just found out it's working again after disabling all plugins and enabling them again. No idea what happened but it fixed it. Your information is interesting though, I'll think about using Debug.WriteLine the next time :) — The Cookies Dog, Jun 08 '13 at 13:40

score 0 · Answer 2 · edited Aug 04 '14 at 12:09

I experienced same issue today, and resolved it. I checked many posts but did not help me. the root reason is you have used different files, which has same void Main() in different classes. When having two files with common function named main(), it will not work. System seems using only the default one called program class.

What you can do is to move the code under program.cs file (if you use C#), then it will be OK in the new window.

score 0 · Answer 3 · answered Aug 20 '21 at 23:34

Following will allow you to see both types of "console" messages:

Paste the following two tests into your code so it runs both lines. These are tests for the output window:

 System.Console.WriteLine($"hello console!");

 System.Diagnostics.Debug.WriteLine($"hello debugger!");

In Visual Studio choose VIEW > OUTPUT. You will see the results above in this output window after changing two settings below.
When NOT DEBUGGING, in the OUTPUT window at the top under "Show Output From" choose: "YourProjectName - ASP.NET CORE Web Server". Run your code. You should see the "Console" text above.
When DEBUGGING, in the OUTPUT window at the top under "Show Output From" choose: "Debugger". Run your code in debug mode. You should see the "Debug" text above.

Console.WriteLine isn't working anymore in VS2012

3 Answers3