how can I kill process or close whole application for my WPF application using c#?
Are you using WinForms? Assuming you want to close it via code (and not from the window's close button), you could use Application.Exit. If you want to kill a process, then you can use the Process.Kill method.
Edit - Since you're using WPF, you can use the Application.Shutdown method.
You can Kill a process using Process.Kill, and close it nicely using
Process.CloseMainWindow.
To find the process, use methods of the Process class such as Process.GetProcessById or Process.GetProcessesByName.
However, to kill another process (depending on the process), you may need elevated permissions. You'll need to start your executable with these in order for this to work, in that case.
You can use Environment.Exit to close your own process, or Environment.FailFast to kill it quickly.
Edit:
Since you're using WPF, you can also use Application.Shutdown to close your own application.
Use the Process class.
To avoid crashes, use an outer catch block - sometimes the System.Diagnostics classes cause operating system level exceptions that I usually want to ignore in the case of a small scale utility app.
Related
I have two projects running in Visual Studio but whenever I exit one the other keeps running. How can I close both?
Ps: I'm using Application.Exit() to close the first one
If you want to use Application.Exit() to close the first process, and you want to close the second process at the same time, try adding the following lines immediately before you call Application.Exit():
Process[] processes = Process.GetProcessesByName("SecondProcess");
processes[0].Kill();
where SecondProcess is the process name of your second process. (You will also need to add a using reference to System.Diagnostics.)
This code assumes exactly one such process will be running; if that's not necessarily the case, you might need to do more.
Use with caution: killing a running process like this might not be advisable! Other methods are possible and probably better but without more information about your exact setup it's hard to know which approach to suggest.
Is there a way to monitor processes starting in the system before they start?
Example:
On programs like ZoneAlarm or Antivirus programs, when you run a program it asks you if you allow running this program or not before it runs...
There's a few ways to do this. If you only need to track process creation coming from a specific program (or a few programs), the EasyHook/Detours method mentioned here will work pretty well, but you effectively need to install a hook on CreateProcess into each program, so it's not a great solution if you want to track all process creation in the system.
There's a specific API for this in NT-based Windows variants (NT/2000/XP/Vista) called PsSetCreateProcessNotifyRoutine(). Unfortunately, you can only call this function from ring0, so it needs to be done in a driver. There's a handy explanation (and code) in this CodeProject article: http://www.codeproject.com/KB/threads/procmon.aspx.
AFAIK, this is just a notification, and does not by itself allow you to tell the system whether the process should be created or not. However, if you needed to do this, you could pause the process (e.g. by attaching to it as a debugger) while your code decides whether to kill it or not.
You should check out the easyhook-continuing-detours project, which is a .NET port of the Microsoft Detours project. It will allow you to hook unmanaged APIs (such as CreateProcess). Check out code examples for a simple FileMon-like program here.
You can find out when processes start via using a real-time ETW consumer - however, to be able to take some action that could possibly cancel the process from starting, you'll have to do something shady / undocumented, like hooking CreateProcess, or using a kernel filter driver to block reads to the EXE.
Just use process creation notifications .
It's included in Windows.
You don't need to hook anything.
I'm currently writing quite a simple app, but it makes a change to the OS which gets changed back when the program is closed.
The worry of course, is if the program crashes. I can do everything in my power to prevent it from crashing, or handling things if it does crash - but I can't stop someone from force closing the process (unless I can?)
Is there a way to catch that event and run just a very quick cleanup before the process exits?
I don't think there is anything you can do if your process gets killed - one approach would be to have your app spawn a helper process that is just there for this case. When your app terminates that process can detect that and "fix" the OS setting as desired before it shuts down itself - obviously this only would work if that other process doesn't get killed first.
You can hook UnhandledException. You can't stop the application terminating, but you can log or do some clean up. This allows you to handle the case of application crashes.
It terms of someone actually just killing the process there's nothing you can do about that.
Program defensively.
Write the original settings to a file. Delete the file when closing. When starting, check whether the file is there - if it is, your process was killed and you know what to return the settings to.
Programming 201 - the basics of transactions, applied to system settings wit hthe program runtime as transaction boundary.
If you don't mind a little interop to C or C++ code, and if you're running on Windows Vista or newer, you could make use of the Application Recovery and Restart APIs. These APIs tell Windows to intercept your process when something catastrophic happens, so that you can perhaps call a little cleanup code before Windows kills the process completely.
See http://msdn.microsoft.com/en-us/library/cc948909.aspx.
Is there any good way to handle a forced exit in C#?
I have a formless C# application that talks to an LCD over serial. Once the application is running, the only way to kill it is with task manager. The trouble with this is that the program needs to turn the LCD off when it is done, and it doesn't look as if my Application.ApplicationExit event is ever fired in this condition.
Any ideas?
Once the application is running, the only way to kill it is with task manager.
My big idea would be to change this.
Stick an icon in the notification area that the user can use to shut your app down properly, or set it up so that running the app again will instead shut down an already-running instance if one exists, or any other way that sounds like a good idea.
Requiring a user to use Task Manager to shut down your application screams poor design.
Write a code in your program loop (with a timer perhaps) to read a file or a registry key. For example if a file at C:\YOURPROGRAM\CLOSEME contains text "closeme", close your program gracefully. Write another program that write that C:\YOURPROGRAM\CLOSEME file. So, whenever you want to shutdown your program, don't use taskmanager, instead, open second program.
Some options:
Write a separate process with a GUI that can start and stop the main process. For example, when you install the Apache web server on Windows the server itself is installed as a service. It can be started and stopped from the system services management panel, but it also comes with a "monitor" process that sits in the notification area, tells you whether Apache is running and lets you start or stop it manually.
If it's acceptable for your use-case, make the application a console application. You can register a handler for when the user presses CTRL+C (see Console.CancelKeyPress) that performs your cleanup before your process exits. This still won't let you handle someone killing the process from Task Manager, but it's very easy to do and might be good enough depending on your situation.
Is there a way to monitor processes starting in the system before they start?
Example:
On programs like ZoneAlarm or Antivirus programs, when you run a program it asks you if you allow running this program or not before it runs...
There's a few ways to do this. If you only need to track process creation coming from a specific program (or a few programs), the EasyHook/Detours method mentioned here will work pretty well, but you effectively need to install a hook on CreateProcess into each program, so it's not a great solution if you want to track all process creation in the system.
There's a specific API for this in NT-based Windows variants (NT/2000/XP/Vista) called PsSetCreateProcessNotifyRoutine(). Unfortunately, you can only call this function from ring0, so it needs to be done in a driver. There's a handy explanation (and code) in this CodeProject article: http://www.codeproject.com/KB/threads/procmon.aspx.
AFAIK, this is just a notification, and does not by itself allow you to tell the system whether the process should be created or not. However, if you needed to do this, you could pause the process (e.g. by attaching to it as a debugger) while your code decides whether to kill it or not.
You should check out the easyhook-continuing-detours project, which is a .NET port of the Microsoft Detours project. It will allow you to hook unmanaged APIs (such as CreateProcess). Check out code examples for a simple FileMon-like program here.
You can find out when processes start via using a real-time ETW consumer - however, to be able to take some action that could possibly cancel the process from starting, you'll have to do something shady / undocumented, like hooking CreateProcess, or using a kernel filter driver to block reads to the EXE.
Just use process creation notifications .
It's included in Windows.
You don't need to hook anything.