I try to create an Application on Windows 8 with VS 11 with C#, And I need to a Button in my App that when people Click on this button , my App going to Close.
But I can't find any Exit or Close function to add, to my Click Event.
how can I make this button? or what is your proposal to solving this Problem?
You shouldn't close your app.
This is one of the concepts of Metro apps.The user switches to a different task and the
Process Lifetime Management aspects kick in, first suspending your application and then later, if needed, terminating it.
Don't close the application's window: let the user know that there is no information currently available and then let them switch away, close, or wait as they'd prefer.
Took from here
If you don't care about certification - e.g. you want a close button in your own debug build to help you with testing - you can call Application.Current.Exit()
You must not implement Close Button.
If you do so, your app will be not able to sell in the store. See "Certification requirements for Windows apps".
3.6 Your app must use the mechanisms provided by the system for those features that have them
(snip)
Your app must neither programmatically close nor offer UI affordances to close it.
You want this?
App.Current.Exit();
Try this.. It worked
App.Current.Terminate();
Related
I'm trying to close Xamarin Forms App from a logout button. However the code I find (example below) leaves the app in a second plan without terminate it completely.
Android.OS.Process.KillProcess(Android.OS.Process.MyPid());
Is it possible to completely close the app without leave it running in a second plan? If so, please provide example code.
There is no approved way of doing this. At the very least not for iOS. There are private APIs or workarounds but if your plan is to have your app in the App Store(s) it will never pass the review process.
A simple way to make it work cross platform is by this command:
System.Diagnostics.Process.GetCurrentProcess().Kill();
However, Apple strongly discourages terminating apps. From here.So suggest that not doing this in IOS.^.^
I'd like to know with a .net language(C# or VB) if I can detect when a new app is launched.
e.g: an user opens Firefox.exe from desktop (not from my app!), is it possible to detect this event from my app? Also is it possible to "pause" it before running it?
So for example when an user double-clicks an application, my app comes first and then it displays a message if he is sure to open that file with Yes and No buttons.
I don't need all code, I just need to know how to catch that event that can happen anywhere in system.
There are some Windows API functions in user32.dll that you can use in your .NET application through System.Runtime.InteropServices.DllImport to get the information you're looking for. Take a look at GetWindowThreadProcessId. For sample code, see http://www.c-sharpcorner.com/UploadFile/satisharveti/ActiveApplicationWatcher01252007024921AM/ActiveApplicationWatcher.aspx. Because applications tend to become active when they are launched, you'll find that the techniques used in that example will cause it to detect new app launches.
That doesn't answer the question about letting the user confirm whether they want to run an app, but it will get you part of the way towards what you are trying to do.
I am having one windows forms application which is designed to do specific tasks in background. Now I want to make sure that this application should be running all the time.
No one should able to close it. If some one closed it from Task Manager (Kill it) then it should restart it self.
I had couple of options for that. I have tried to make one window service which has timer and which can be check at every 1 minute that if process is not found then it will launch the process. But I have gone through couple of articles and they are saying that this is not nice idea. Is there any other way round to keeping alive my application in windows.
In my idea also if someone closes my service then also I can't detect if my WinForms application is closed or running.
What is best way to do so? I am ready to give highest privileges and I have thought that option as well that If someone kill process of my application then computer should be shut down it self.
Please share better idea to do so.
If you don't want the user closing your app, make it as difficult for him as possible:
launch it maximized
remove the frame of the window (and close, maximize,minimize buttons with it)
launch it TopMost
set ShowInTaskbar of your forms to false
ask 10 times "are you sure you want to exit???" :)
set e.Cancel to true in FormClosing event, etc...
About the Task Manager:
I think you can disable task manager altogether http://www.techulator.com/resources/3480-how-disable-task-manager-windows.aspx
Or you can hide the process (ugly and virus-like): How do I hide a process in Task Manager in C#?
Or you can sort-of make it harder to kill the process: Making an app/service such that trying to end/kill its process in Task Manager would result in "Unable to Terminate Process"
Then, if the user still manages to close your app, you can do what most people on the Internet consider a Very Bad Idea and start it from the service. As long as you are concious of the risks.
There are plenty of resource out there that tell you how to start an interactive app from the service (so evidently some people are doing it too), for example:
http://blogs.msdn.com/b/winsdk/archive/2009/07/14/launching-an-interactive-process-from-windows-service-in-windows-vista-and-later.aspx
you should know that it is impossible to prevent task manager not to close your application. and its not a proper idea to force the user.
But, if you insist I think the best way is through services with timer or thread whichever suits your solution to check its process and run it if not exists. and you didn't mention in your post that what was the reason of not using this method and why it is not a good method.
hope it helps you decide better.
I need to know which event fires within an WPF application if I cancel it by Windows Task Manager?
The idea is to terminate internal App. job accurately.
Thank you!
When you use the "Processes" tab there is no event, because your process is simply killed.
When you use the "Applications" tab, a normal WM_CLOSE message is sent to the top level of your application. See the last answer here on how to detect this in a WPF application.
The idea is to terminate internal App. job accurately.
You can't do this reliably. If the user is ending the application that way, something has either gone badly wrong or they simply don't care. There's nothing you can do, you're toast. Don't worry about cleaning up after yourself: the operating system will do that for you, no thank you required.
The best thing that you can do is handle the standard close events. Those will get triggered if the user requests to end your app in a polite way, either via the normal means or through Task Manager (Task Manager will try to ask nicely first if the user clicks "End Task" from the "Applications" tab). But since I assume you're already doing that, you've done all that you can.
Handling the event from Task Manager is not possible as the way it works for ungracefull shut downs of applications.
However, you can try to handle the Application class' SessionEnding event which is described in MSDN at below link:
http://msdn.microsoft.com/en-us/library/system.windows.application.sessionending.aspx
I have a windows form application which needs to be the TopMost. I've set my form to be the TopMost and my application works as I'd like it to except for in one case.
There is a 3rd party application (referred to as player.exe) that displays SWF movie files on a portion of the screen that popup on top of my application.
Using Process Monitor I determined that player.exe application calls
flash.exe <PositionX> <PositionY> <Width> <Height> <MovieFile>
in my case:
flash.exe 901 96 379 261 somemovie.swf
Since flash.exe is being spawned in a new process after my form has been set to the TopMost it is appearing on top of my application.
First thing I did was make my application minimize the player.exe main application window hoping that this would prevent the Flash from appearing also. But, unfortunately it doesn't... even with the window minimized whenever the flash movie starts it shows up at the pixel location (901,96). I then tried creating a timer to keep setting the form.TopMost property to true every 10ms. This sort of works but you still see a very quick blip of the swf file.
Is there some type of Windows API call which can be used to temporarily prevent player.exe from spawning child processes which are visible? I admit it sounds a little far fetched. But, curious if anyone else has had a similar problem.
Addendum:
This addendum is to provide a reply to some of the suggestions layed out in Mathew's post below.
For the emergency situation described in the comments, I would look at possible solutions along these lines:
1) How does the third party application normally get started and
stopped? Am I permitted to close it
the same way? If it is a service, the
Service Control Manager can stop it.
If it is a regular application,
sending an escape keystroke (with
SendInput() perhaps) or WM_CLOSE
message to its main window may work.
Easiest way to close the app is to CTRL-ALT-DEL, then kill process. -OR-
The proper way is to Hold ESC while clicking the left mouse button... then input your username and password, navigate some menu's to stop the player.
There is no PAUSE command... believe it or not.
I don't think using WM_CLOSE will help since minimizing the application doesn't. Would that kill the process also? If not, how do you reopen it.
2) If I can't close it nicely, am I permitted to kill it? If so,
TerminateProcess() should work.
I can't kill the process for two reasons. 1) Upon relaunch you need to supply username/password credentials... There may be a way to get around this since it doesn't prompt when the machine is rebooted but... 2) Whenever I kill the process in task manager it doesn't die gracefully and asks if you want to send an error report.
3) If I absolutely have to leave the other process running, I would try
to see if I can programmatically
invoke fast user switching to take me
to a different session (in which there
will be no competing topmost windows).
I don't know where in the API to start
with this one. (Peter Ruderman
suggests SwitchDesktop() for this
purpose in his answer.)
I got really excited by this idea... I found this article on CodeProject which provides a lot of the API Wrapper methods. I stopped implementing it because I think that in order for desktop's to work you must have explorer.exe running (which I do not).
EDIT2: On second thought... maybe explorer.exe isn't needed. I'll give it a try and report back.
Edit3: Was unable to get the code in that article working. Will have to put this on hold for a moment.
Answer Summary
As one might have expected, there is no simple answer to this problem. The best solution would be to problematically switch to a different desktop when you need to guarantee nothing will appear over it. I was unable to find a simple C# implementation of desktop switching that worked and I had a looming doubt that I would just be opening a whole new set of worms once it was implemented. Therefore, I decided not to implement the desktop switching. I did find a C++ Implementation that works well. Please post working C# virtual desktop implementations for others.
Setting the TopMost property (or adding the WS_EX_TOPMOST style to a window) does not make it unique in the system. Any number of topmost windows may be created by any number of applications; the only guarantee is that all topmost windows will be drawn 'above' all non-topmost windows. If there are two or more topmost windows, the Z-order still applies. From your description, I suspect that flash.exe is also creating a topmost window.
Aside from periodically forcing your window to the top of the Z-order, I think there is little you can do. Be warned, however, that this approach is dangerous: if two or more windows are simultaneously trying to force themselves to the top of the Z-order, the result will be a flickering mess that the user will likely have to use the task manager to escape.
I recommend that your program not attempt to meddle with other processes on the computer (unless that is its explicit purpose, e.g. a task manager clone). The computer belongs to the user, and he may not value your program more highly than all others.
Addendum:
For the emergency situation described in the comments, I would look at possible solutions along these lines:
How does the third party application normally get started and stopped? Am I permitted to close it the same way? If it is a service, the Service Control Manager can stop it. If it is a regular application, sending an escape keystroke (with SendInput() perhaps) or WM_CLOSE message to its main window may work.
If I can't close it nicely, am I permitted to kill it? If so, TerminateProcess() should work.
If I absolutely have to leave the other process running, I would try to see if I can programmatically invoke fast user switching to take me to a different session (in which there will be no competing topmost windows). I don't know where in the API to start with this one. (Peter Ruderman suggests SwitchDesktop() for this purpose in his answer.)
You can use the Process class to start flash.exe directly - and use an appropriate ProcessStartInfo settings to show the window in a hidden state - or with a WindowStyle of hidden or minimized.
You could also consider using the SetWindowsHookEx API to intercept the process start API calls, and when the process is flash.exe run some code to restore you window to top-most status.
Matthew's answer is excellent, but I suspect you may be asking the wrong question. Why does your application need to be topmost? If you're trying to create a kiosk or some such, then topmost is not the way to go.
Edit: After reading your response to Matthew's comment, I'd suggest creating a new desktop and switching to it before displaying your alert. (See CreateDesktop and SwitchDesktop in MSDN.)