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Closed 10 years ago.
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Application.Exit
I have a Winforms app in which Application.Exit() fails to run.
public Form1()
{
InitializeComponent();
path=parseINI();//Gets path from ini file
}
In my case, Application.Exit() is being called from the parseINI method, where it doesn't work. Is the problem that its being called when the app is starting? I stuck it in another method that runs after the form is loaded, and it works there. I did use Environment.Exit in my parseINI method, and that worked (despite it being for console apps rather than WinForms).
EDIT: I should probably add that its there as a check, to make sure a file being read is formatted correctly, if it is, then its not called, otherwise the program exits.
This might be because you still haven't started the application via Application.Run when the Form ctor executes.
The common startup code template goes like this:
Application.Run(new Form1());
If that is the case, you call Application.Exit before Application.Run. So after you have called exit, you effectively call Run, and therefore, the application runs.
Call the Form.Close() method inside parseINI() instead of Application.Exit()
The Environment.Exit() method terminates the application, closing the application thread. Indeed, from the documentation:
Terminates this process and gives the underlying operating system the specified exit code.
Why do you have to shutdown your application from within your parseINI method?
Anyway, the method call for Application.Exit() is not working for you, because, reading the MSDN page:
This method stops all running message loops on all threads and closes all windows of the application. This method does not force the application to exit. The Exit method is typically called from within a message loop, and forces Run to return. To exit a message loop for the current thread only, call ExitThread.
Then, you can add this line to your constructor, to "run" the application, allowing you to use Application.Exit():
Application.Run(new YourForm());
You can find an interesting discussion here: http://geekswithblogs.net/mtreadwell/archive/2004/06/06/6123.aspx
Read this answer for details.
Furthermore, read this important SO question to better understand the difference between Environment.Exit() and Application.Exit().
Related
Following are the ways by which we can exit an application:
Environment.Exit(0)
Application.Exit()
Form.Close()
What is the difference between these three methods and when to use each one?
The proper method would be Application.Exit(). According to the Documentation, it terminates all message loops and closes all windows thus giving your forms the possibility to execute their cleanup code (in Form.OnClose etc).
Environment.Exit would just kill the process. If some form has e.g. unsaved changes it would not have any chances to ask the user if he wants to save them. Also resources (database connections etc.) could not be released properly, files might not be flushed etc.
Form.Close just does what it says: it closes a form. If you have other forms opened (perhaps not now but in some future version of your application), the application will not terminate.
Keep in mind that if you use multithreading, Application.Exit() will not terminate your threads (and thus the application will keep working in the background, even if the GUI is terminated). Therefore you must take measures to kill your threads, either in the main function (i.e. Program.Main()) or when in the OnClose event of your main form.
they are all fine.
but form.Close() won't close your application
it closes the form and after that
the main-method returns an int (exitcode).
if you want that your application exits with exitcodes use
Environmet.Exit(exitcode) or return the exitcode in the main-method
This question already has answers here:
How do I properly exit a C# application?
(4 answers)
Closed 6 years ago.
I used to call Application.Exit terminate my application. At some point in time, I start to use a DLL, and I cannot fully terminate my application (a thread is running).
However, I can call Environment.Exit(0) and terminate my app completely.
I have read some useful posts.
[Closing Applications
[http://geekswithblogs.net/mtreadwell/archive/2004/06/06/6123.aspx][2]
It seems
Application.Exit() is recommended for Windows application and
Environment.Exit(exitCode) is recommended for console application
That's what I read from other posts.
===== The reason that I asked this question, and Something is still unclear to me:
Now, I just add Environment.Exit(0) at the end of Application.Exit event handler, since I had the event handler for Application.Exit and save some state information in the handler.
I am still not sure that I use this in a correct way. In other words, does this make sense to call both Application.Exit() and Environment.Exit(exitCode)
If you really just needs to terminate the App instantly and terminate all the threads, then you need to use Environment.Exit(0).
If you want your Forms' Close events to fire and your threads to continue their work, you need to use Application.Exit();
It really depends on your situation. The first is like you terminating the process (Killing it). The Second is like sending a message to the App and politely asking it to finish everything in hand and then close for good. This allows to save some state information by firing the closing events if implemented.
Following are the ways by which we can exit an application:
Environment.Exit(0)
Application.Exit()
Form.Close()
What is the difference between these three methods and when to use each one?
The proper method would be Application.Exit(). According to the Documentation, it terminates all message loops and closes all windows thus giving your forms the possibility to execute their cleanup code (in Form.OnClose etc).
Environment.Exit would just kill the process. If some form has e.g. unsaved changes it would not have any chances to ask the user if he wants to save them. Also resources (database connections etc.) could not be released properly, files might not be flushed etc.
Form.Close just does what it says: it closes a form. If you have other forms opened (perhaps not now but in some future version of your application), the application will not terminate.
Keep in mind that if you use multithreading, Application.Exit() will not terminate your threads (and thus the application will keep working in the background, even if the GUI is terminated). Therefore you must take measures to kill your threads, either in the main function (i.e. Program.Main()) or when in the OnClose event of your main form.
they are all fine.
but form.Close() won't close your application
it closes the form and after that
the main-method returns an int (exitcode).
if you want that your application exits with exitcodes use
Environmet.Exit(exitcode) or return the exitcode in the main-method
I want to do some initialization of various things at runtime of my WinForms application. I'm looking specifically at the Program.cs file that every WinForm application has. In it, I see:
[STAThread]
static void Main() {
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new frmMain());
}
I know that this is what starts up the application and creates the initial form (in my case, an instance of frmMain).
Can I not just put my initialization code before Application.Run()? The initialization I need to do is to check a few registry entries, create them if necessary, and connect to a database. Will any feature not be available to my instantiation code if I put it before Application.Run()?
Application.Run() starts message loop for your main thread. SO before that line of code you can do anything except what is dependent on windows messages (click, keyup, ...)
A Windows Forms application starts when the Main method is called. You can implement initialization procedures on the Main function. However, to initialize a Windows Forms application fully and start it routing Windows Forms events, you need to invoke Application.Run.
Read about Application
Yes, no problem, the code in Main() is boilerplate but not cast in stone.
Do keep in mind that any code you run before calling Application.Run() will delay the startup of your user interface. Once that goes over a second or two, give or take, you might want to consider displaying a splash screen so that the user gets some visual feedback that your program got started. Well supported by the .NET framework, check this answer.
One important thing you don't have available before Run is a valid SynchronizationContext.Current. So if you use any kind of event-based asynchronous pattern components, they'll seem to work just fine, but will fire their events on a thread pool thread instead of the GUI thread.
Because of this, any asynchronous startup code that queues completion events to the GUI should be started from an event, not before Run.
As long as you don't need to access anything declared in frmMain you should be OK.
However the MSDN states:
Begins running a standard application message loop on the current thread.
so you won't have access to the message loop.
There is another overload Application.Run(ApplicationContext) that will let you execute code before your form is displayed - this appears to be the way to go.
The example code on this page does some initialisation before showing two forms, so you should be OK with your model.
What is the best way to kill an application instance?
I am aware of these three methods:
Application.Exit()
Environment.Exit(0)
Process.GetCurrentProcess().Kill()
Can anyone tell me which is better or when using each of the above would be appropriate?
guidelines from c# faq:
System.Windows.Forms.Application.Exit() - Informs all message pumps that they must terminate, and then closes all application windows after the messages have been processed. This method stops all running message loops on all threads and closes all windows of the application. This method does not force the application to exit. The Exit method is typically called from within a message loop, and forces Run to return. To exit a message loop for the current thread only, call ExitThread. This is the call to use if you are running a WinForms application. As a general guideline, use this call if you have called System.Windows.Forms.Application.Run.
System.Environment.Exit(exitCode) - Terminates this process and gives the underlying operating system the specified exit code. This call requires that you have SecurityPermissionFlag.UnmanagedCode permissions. If you do not, a SecurityException error occurs. This is the call to use if you are running a console application.
Killing the process is likely not recommended.
If this is a Windows Forms application, use Application.Exit(). That will close the program nicely.
Just a quick answer, I would always use the "Exit" option when it will work. It is a much cleaner way to do it.
To "Kill" a process means exactly that, and therefore the program does not get to do any cleanup work it might want to do (like saving configuration, saving other files, etc...). Unless you know what the process is and that it does not have any "cleanup" to do, and even then, it's just cleaner to use "Exit."
There does not appear to be any difference between the two "Exit" options you mention, I would wager that the first is simply implicitly passing the zero value.
foreach (Process proc in Process.GetProcessesByName("WindowsFormsApplication1.vshost"))
{
proc.Kill();
}