I have a WPF application, after closing the app its process app.exe *32 is still running in the processes list in task manager.
I need this to close as when I make an edit to my code I get the following error -
Unable to copy file "obj\x86\Release\frontEndTest.exe" to "bin\Release\app.exe". The process cannot access the file 'bin\Release\app.exe' because it is being used by another process.
I am aware that this sort of question has been asked before here.
However the solution did not work for me by changing my Assembly.cs to -
[assembly: AssemblyVersion("2.0.0")]
[assembly: AssemblyFileVersion("2.0.0")]
I thought that perhaps if I were to find the Window closed event and puttting something like - Process.GetCurrentProcess().Kill(); in the event so that when a user closed the application from the red 'x' button in the top right of the form this would perhaps kill the process?
So your process is still alive after you've shut it down. This usually means you have a thread that keeps it alive. Here's how you can track it down.
First, attach to it in the debugger:
Now open the threads list:
Double-click each thread you see here:
And you'll be taken to what the thread is currently doing:
That, right there, is what preventing the app from shutting down. One would have to exit that loop for the app to exit (or, alternatively, set Thread.IsBackground to true).
Environment.Exit(0);
Terminates this process and gives the underlying operating system the specified exit code.
0 is returned upon successful completion.
Related
I want to start vscode as an external editor in a program that Im writing in c#. I use the Process class. I can do that but I also like to be notified when a particular instance is closed. Now I run into problems. If I only start one instance of vscode, the process terminates when that window is closed which is what I want. However, if I start a second vscode that process will terminate immediately. This becomes an issue when the user already has an instance open and use my program.
Anyone with an idea on how this can be solved?
Two parts are necessary to answer your question.
The first is the pure C# one: How to start a process and wait for it to end
Everything you need for this is in the Process class.
To start a process: Process.Start
Once started, to wait for exit, you have a few options:
Process.WaitForExit
Process.WaitForExitAsync
Process.Exited (this is an event handler that you can subscribe to)
Then there is another part needed to answer the question: How VS Code behaves when started from the command line and its options
By default, VS Code will return immediately after starting (so as not to block a shell if it was started from CLI). So, you'll need to pass a few parameters.
Based on the previous link, those would be:
-w or --wait => Wait for the file to be closed before returning.
-n or --new-window => Opens a new session of VS Code instead of restoring the previous session. (this is default behaviour, but you might want to specify it anyways in case this ever changes [or the user changes this])
I am trying to figure out what changed within a project that now causes the application to not exit the debugger when I close the application I am debugging. I have also noticed that unhandled exceptions no longer invoke the unhandled exception handler, I am not sure if it's related.
This is probably due to other threads, which are not set as background threads, keeping the application alive. Background threads will terminate when the application does, whereas foreground threads will keep the rest of the application alive until they complete.
One way to check for the thread(s) that are responsible is in the debugger, as follows:
Run your app in the debugger
"Exit" your app.
Wait until the app should have exited but hasn't
Break into the app using the "pause" button
Open the "Threads" debugging window
Look for any threads in this window. Chances are there will be one, or a few threads showing. See if you can identify what they are by the info in the window.
It may also help to open the "Stack" debugging window and then double-click on each thread in the "Threads" window in turn and look at the contents of the "Stack" window. You may be able to see what any stuck threads are trying to do.
The debugger exits when all the threads exit. You've probably created an extra thread and done nothing to terminate it.
And this would explain unhandled exceptions being uncaught: if they happen on a different thread you won't see them on the main thread.
Most certainly the application has not actually terminated. Do you have any other threads running? An application will not shut down until all foreground threads have terminated.
After I close the main window of my program, the process is still running in the background.
How can I check what is the cause for this weird problem?
(I don't know which part of my program code is relevant)
First check that the value of your application's ShutdownMode property is equal to ShutdownMode.OnMainWindowClose -- if it is not, see if the actual value is preventing the app from closing.
If this does not solve the problem, then you have one or more non-background threads still running after the main window closes, preventing the process from shutting down. Break into the debugger and see how many threads are still alive and what they are doing; this will lead you to a solution.
To see the Thread that is currently running and stopping your application from termination just press "Break All" at the Visual Studio and see where the cursor stops.
Note: you can force application to terminate by calling Environment.Exit();
Another reason could be that someone set the Application.ShutdownMode to OnExplicitShutdown.
One possibility is that you create threads which are not set to background or you're calling code that does that; that may keep your process "alive" even after you shut down your main thread.
Make sure that you terminate all of your threads before you exit or you set their IsBackground property to true.
We have an application written in .net, c#, winforms. We noticed that sometimes when closing the application, the process remains.
I'm not sure how I can reproduce that behavior, so I'm looking for some clues as to why the application wouldn't exit.
The application uses a bit of background threads. Thread pools. Wondering if that could be the cause. Anything else could have this effect?
If you have thread's that have IsBackground property set to false that are alive after application is closed, they will remain
The application uses a bit of
background threads. Thread pools.
Wondering if that could be the cause.
Anything else could have this effect?
It most definitely could be the cause though I cannot be certain that it actually is. One way to test this hypothesis to make sure all threads that have been explicitly created are designated as background threads. This can be done by setting Thread.IsBackground = true which will allow the application to terminate if the main thread ends. If there is at least one thread for which IsBackground = false then the CLR keeps the host process running.
Its likely to be a thread left running. If you have a look at the process in task manager you can see when a thread starts, and how many are left running when it exits by adding the 'Threads' column from the view menu.
I would start by making sure you start and end on the same thread count.
Get Process Explorer and possibly Process Monitor and see what thread is left suspended or running.
If you are able to run in debug and you close the form, VS should not return to the normal code edit mode (it will still have the pause and stop buttons from debug active). You can then press Pause and check the Threads window to see where the call stacks are stuck for threads that are still active.
I've worked on quite a few WPF solutions, and this is the first time i am seeing this problem.
Today it started happening intermittently. where after closing my WPF window, the .exe is still running under visual studio.
so i have to kill my program.exe manually in order to compile again.
Initially i thought because i overrode application start/exit/exception .. but i commented all that out, and it is still happening.
In fact, i see multiple instances of my program.exe in process explorer!
Can't figure out what is causing my exe not to exit. Is there any explicit dipose logic i can add in applicaton exit event to ensure it really exits?
My application consists of single window, and multiple user controls as views.
update
if i open in debug mode. and close the main WPF window, my visual studio does not stop debugging. however call stack window is empty.
You can use the Application.Exit event to log when your application shuts down.
Alternatively, you can attach the debugger to your running instance (even if it wasn't started in the debugger) then pause it to see where it's at. Make sure to look at the Threads tool window, as you may pause outside the UI thread.
This should take care of it, though its probably better to try to figure out the underlying issue.
System.Diagnostics.Process.GetCurrentProcess().Kill();