I am developing WTL GUI application.
I want to print something on console.
How to enable console printing in win32/WTL application.
Use AllocConsole to attach to a new console. (This will fail if your program is being run from a console window in the first place, but that's ok.) Also look at this page for a fully worked example.
Related
When I debug a unit-test with Visual Studio 2017, all the console output is logged and I can examine it by clicking the "Output"-link in the result box of the unit-test (I'm using the built-in Test-Explorer).
However, since I do log a lot to console at runtime which is even color coded so important stuff is more visible, I can't see this color coded output using the "Output"-link, because it's just plain black text on white background.
Is it possible that Visual Studio shows all the output directly in a console window when debugging the tests so I see the output as I would see it when actually running the application outside of a test?
You cannot (or it is very tricky at least) open a console window from a unit test - I've tried with the top 2 answers from the following post, and they didn't work: Show Console in Windows Application?
You can make the Debug.Write... methods write to the Console when you are running/debugging the application itself (not the unit tests) with this code, though:
ConsoleTraceListener listener = new ConsoleTraceListener();
Debug.Listeners.Add(listener);
Any calls to Debug.Write... methods after this code will also output to the console.
Standard output is the only way to display the test output, when we use some output method in our test like Debug.WriteLine(); Console.WriteLine(); etc.
I also tried to change the font of the test output but it seems there is no that option is VS 2017, even someone though someone mentioned this before:
Is there a way to change the Font used in the VS2012 Test Output Window?
Similar case discussed in this thread, even some reply claimed that we could manually launch the console window, but they are 100% sure about it.
If you really need change the font or the color of the test output, in Visual Studio you go to Help -> Send feedback to VS developing team to provider your suggestion .
Operating Environment: Windows 7, Visual Studio 2010, CLR GUI.
So I've been given the unglorious task of enhancing a GUI application that is started from a command prompt. Because it is. Because poor design decisions by previous implementers. Anyway, it launches one of several GUIs depending upon the input arguments.
I'd like to be able to print back to the same command prompt window if (when) the user types something that the code doesn't understand.
Here's what I've tried (none of which output anything):
int main( array<System::String^>^ args )
{
Application::EnableVisualStyles();
Application::SetCompatibleTextRenderingDefault(false);
OutputDebugString("hello");
Trace::WriteLine("hello");
Debug::Trace::WriteLine("hello");
Console::WriteLine("hello");
std::cout << "hello";
printf("hello");
return 0;
}
Thanks in advance!
Update: I don't want to use AllocConsole(), as that opens a new console that disappears along with all of the data when the application exits. Similarly, a pop-up message box won't work. I'm looking for a way to make the output persistent.
The only way I can get output from the application to date is via a message box (non-persistent) or opening a new console that disappears when the application exits (via AllocConsole() ). And I'm running from a command prompt, not the debugger's "Play" button.
Update
Why the down-vote for not doing research? I spent a day trying to solve this, looking through dozens of posts trying to find a solution, and to date I've found others looking for the same answer, but not finding it. AllocConsole() or changing the project type is always the solution, but neither is a solution for me.
Update
I added the "full code", which is the 2 statements. THAT IS ALL THE CODE. So simple. I'm skipping the start of the GUI because I don't care about that right now, I just want it to print back to the console where the application was started. The most basic HelloWorld. If there are project settings I need to post, I don't know which ones would be relevant. This is where I want to print to the console, before the GUI is ever up. I can't show the GUI if there is an error in the user input.
Right click on the project, select Properties
Under Linker -> System, Change Subsystem from Windows to Console.
A Windows subsystem application cannot write to console, but by changing the subsystem to Console (which can write to the calling console), the Form part of the application can still work (tested in Visual Studio 2010).
When running a console application in Visual Studio via "Start without Debugging" (Ctrl+F5), the console remains open at the end of the run asking to
Press any key to continue . . .
thus requiring to activate the window and hit a key. Sometimes this is not appropriate.
Why this matters:
At the very moment I write json serialisation code, my workflow goes like this:
adapt c# code
run a console app that writes file out.json
view out.json in the browser with a json viewer
do this again and again, no need to debug anything, just trimming serialisation and check output is good.
It is workflows like this, where the "press any ..." behavior is hindering as it requires the steps
activate the console window
press key
.
No answers:
Starting the application outside VS in a separate console is not an answer.
Saying, you dont need this.
I'm pretty sure that you cannot affect or change this behavior.
As you mention, it has nothing to do with your application itself, because it doesn't do it when you double-click on the EXE. You only see this effect when you run the app from within Visual Studio without the debugger attached.
Presumably, when you invoke Ctrl+F5, Visual Studio is running your app in a particular way that causes the console window to remain open. I can think of two ways it might be doing it:
%COMSPEC% /k "C:\Path\To\YourApplication.exe"
or
%COMSPEC% /c ""C:\Path\To\YourApplication.exe" & pause"
With either of these, the pausing behavior you're seeing is baked right into the command used to launch your app and is therefore external to your application. So unless you have access to the Visual Studio sources, you're not going to change it. Calling an exit function from your app won't have any effect because your app has already quit by the time that message appears.
Of course, I can't see why it really matters, aside from an issue of curiosity. This doesn't happen when you start the app with the debugger attached, which is what you'll be doing 99% of the time when you launch the app from the IDE. And since you don't ship Visual Studio along with your app, your users are going to be starting the app outside of VS.
In response to the updates made to your question, the best solution would be to change your app so that it is not a console application. This behavior doesn't affect standard Windows applications; when they get closed, they close for good.
If you do not require any output on the console window, then this is very simple to do: just change the "Application type" in your project's properties. A Windows Forms application will work just fine. If you do not display a window (aka form), one will not be automatically created. This is the difference between regular Windows applications and console applications, which always create a console window, whether you need one or not.
If you do need to display output on the console window, you have a couple of options:
Create and use a simple form with a ListBox or ListView control. Each line that you would normally output to the console, you add as a new item to the list control. This works well if you're not using any "advanced" features of the console.
P/Invoke and call the AllocConsole function to create a console that your Windows application can use. You do not need a form for this.
I found a solution that works if you are using python (I could not test anything else).
You need to go to
Tools -> Options -> Python Tools -> Debugging
Uncheck Wait for input when process exits normally.
I hope you can apply this somehow to your problem.
2020 UPDATE : Microsoft has listened.
It also closes the console in "Start Without Debugging" mode ;)
The setting is a little buried, but works :
Well, at least in Visual Studio 2010, typing
Console.ReadKey(true);
Removes the "Press any key to continue....."
According to the VS2019 documentation:
Automatically close the console when debugging stops: Tells Visual Studio to close the console at the end of a debugging session.
It works, but only if you make sure your project starts with the debugger on. This sounds trivial, but I was trying at first with a solution with two projects, one Console one to copy files to use in my app, the other to run the actual app. I set the Console one to Start without debugging because I don't need debugging on it, but that did not close it after it ran. Only when setting it to Start (with debugging) this option worked.
In vs2017 you have to uncheck the python environment setting under the vs-options:
in german: Auf Eingabe warten, wenn der Prozess normal beendet wird
I am trying to launch an application via the ShellExecute() API call. This application contains only a main function which does some processing and exits.
Now I have put DebugBreak() in starting of main. When ShellExecute() is called the application is launched successfully but it does not ask for breaking.
How can I debug my application when launched from other application using ShellExecute()?
I am using VC++ .
If DebugBreak() isn't workign for you, try _CrtDbgBreak(). Note that _CrtDbgBreak only works in a debug build.
_CrtDebugBreak definitely works for me to make a launched process break on startup, although I'm pretty sure DebugBreak does also.
Note that both functions will make it look like the process has crashed, since they raise an exception. That is normal and gives you the opportunity to attach a debugger via the crash dialog. (The crash dialog also lets you terminate the process; don't use that, obviously.)
Also note that if you have a catch-all SEH exception handler around your main then the exception raise by DebugBreak & friends will be swallowed up and the app will simply exit without showing the crash dialog or letting you attach to it.
You can't do this with VC++; with WinDbg this is just .childdbg 1 to debug all child processes. With VC++, you can use Image File Execution Options in a pinch - check out http://codereflect.com/2009/09/20/how-to-debug-child-process-using-windbgvisual-studio/ for more info. Really though, if you've got the time to learn WinDbg, it's much better at this.
you can try this, it's ok in xp system.
app.exe is your application name,
-s1...-s3 is command line arguments.
HINSTANCE hRet = ShellExecute(NULL, L"open", L"vsjitdebugger.exe", L" app.exe -s1 a1 -s2 a2 a3 -s3", szExePath, SW_SHOW);
There is now a Microsoft Child Process Debugging Power Tool.
The method I use for things like this is to embed some interactive code, which you can either delete afterwards, comment out or conditionally enable. In a few cases we have this code enabled by querying an environment variable which is set by the tool that launches the main application. This allows me to click a check box, hit launch and have the breakpoint dialog in seconds.
if (MessageBox(NULL,
_T("Attach the debugger now, then choose Yes to hit a breakpoint"),
_T("Attach Debugger"),
MB_YESNO) == IDYES)
__debugbreak();
This gives you the ability to attach the debugger when the dialog box appears and the option to hit a breakpoint or not. My earlier versions didn't give me the option and after a while I realised some of the time I wanted the breakpoint, and some of the time I didn't.
When developing a Win32 Application (non-console application) in Visual Studio 2005, is there any way to get the same sort of output as you do from the console?
For instance, say I want to see log statements (such as I would with cout in a console application) to trace the path my program has taken in the code.
My first thought would be that this could be done through the Output tab selecting something from its "Show output from:" dropdown, when debugging but I don't know what API I need to do this...
For example say I had the following in my windows application and wanted to know when the following function enters and exits writing the result to the Visual Studio window above.
void someFunction(void)
{
Win32APIConsoleLog("BEGIN: someFunction()");
// ...
Win32APIConsoleLog("END: someFunction()");
}
Is this possible? And if so, what what libraries do I need to include and what function calls do I need to make to write out to the console window?
OutputDebugString.
I assume that you want to write to the debug console, since that's what your screenshot shows. OutputDebugString is a nop when no debugger is attached, but it allows you to log whatever you want to the debugger's output.
OutputDebugStringW(L"This will go to the output.\n");
// or
OutputDebugString("This will go to the output.\n");