This question may be some times funny for all. Created an application in c# but my problem is in implementing that, the application should not be stopped in any case with out system restart. How can i do this? I heard about circular reference what is it and how can i apply it in my windows application
if it can be done using windows service then service can also be stopped from task manager but i don't want my application to stop
you can not do this, since the application can be closed using Task Manger. So the only way is to create two processes first represent your app second to check if your app is closed run it again.
You could create a service, as suggested in one comment. This will prevent people without administrative controls from stopping it. If people do have administrative control, they will be able to stop your program quite easily.
I checked for tricks kids use to go around Net Nanny. The most common trick is to install a virtual machine and use that for accessing the network. Users who aren't administrators can't install Virtual Box or the like, so the service solution will work against these, as well.
Related
I'm new in programming with .Net and C# and, as said in the title, I have a WPF app which is accessible in a system tray icon and I want to run it a windows service.
Typically, I want an output like it was described in an answer provided in a discussion here.
If you want it in the system tray I think what you'll have to do is make it a Windows service. I've only written 1 Windows Service and that was years ago, but I believe that's what you'll have to do. If I'm correct about writing a Windows service, then what I would suggest you do is create a new Visual Studio solution and add two projects to it. One would be a DLL which would run as a Windows service. The second project would be a WPF project that will be your UI the user interacts with. Then you'll have to use some messaging system to communicate between the two. For the action messages that would mimic what Outlook does, I've used some WPF toast messages to accomplish that. If you Bing/Google "WPF toast popup" you'll get lots of results.
I have many searched in Internet and find some helpful answers like:
URL1
You can't, not directly, because the windows service will necessarily start when the machine does, not when a user logs in. The service will also be running in a different context, likely as a different user. What you can do is to write a separate system tray based "controller" that interacts with the service.
URL2
It needs some effort to achieve. Well, just two hints: 1) use static property System.Environment.UserInteractive to detect in which mode your application is running, see http://msdn.microsoft.com/en-us/library/system.environment.userinteractive.aspx; 2) get rid of app.xaml, because it will force starting WPF Application in all cases; instead, create and run and instance of System.Windows.Application (or better, a specially derived class) explicitly and only for interactive mode, see http://msdn.microsoft.com/en-us/library/system.windows.application.aspx.
And, I could not apply their instructions.
Thanks advance!
I have a windows app (written in C#...) that is installed on multiple remote workstations, the installation is being done by a MSI package.
An updated installation with changes to the program is being conducted from time to time, at this point, for each update, for each station we need to go to where the .MSI is located copy it and run it and only than start the app.
I would like that: whenever a user tries to start the app a background process will be initialized that will compare the installed version with the most recent version on the .msi location and if an update in needed will run the installation and than start the app.
The problem is that it can't be done from within the program since the program cannot be running when the installation/upgrade is taking place. Another consideration is that not all the stations operating at the same time so I can't schedule a timely upgrade, and it can't be done on stations boot since sometimes the updates needs to be done while the station is already operating(the station has several functions beside my app).
I have considered several approaches, it seems like a windows service could do the trick but I don't know if it could be "bound" to the initialize of the program and if it could suspend the program to do the necessary checks and updates and only than to restart the app.
I am open to all ideas so please don't feel obligated to my ideas...
at this point, for each update, for each station we need to go to where the .MSI
is located copy it and run it and only than start the app.
Fire the guy pretending to be a system administrator.
Unless you have done something odd in your installer - it should be doable with your standard software distribution package. Heck, I can roll out updates with active directory ONLY and no third party software as long as the MSI allows administrative no ui installs.
You try to fix a non-problem. Software distribution is a solved solution for the last 15 to 20 years. MSI was particularly created to handle this issue because other approaches demonstrated issues.
So, whoever pretends to be the administrator on your company needs to get his act together and be one. Do nothing (except making a good MSI) and let the admin do his job.
Everything else just creates a lot of problems (at least in the cost side). And it is totally not needed.
I'm updating my answer,
This is what we did....
Create the Installer / Package ( you can install for all users here)
Generate Bootstrapper (https://msdn.microsoft.com/en-us/library/ms165429.aspx
You can use this tool create bootstrapper (http://www.softpedia.com/get/Programming/Other-Programming-Files/Bootstrapper-Manifest-Generator.shtml)
Add dependencies and other conditions in bootstrapper
Set the URL for updates
This will solve your problem. I was too quick to answer but this how we did.
Thanks.
Some comments and answers about the assumptions in the question:
"I would like that: whenever a user tries to start the app a background process will be initialized that will compare the installed version with the most recent version on the .msi location and if an update in needed will run the installation and than start the app."
The only time this is likely to be a useful approach is when the MSI is at a company's web server. The web site can host a web api that you send your ProductCode, Version, Upgrade to and it reports whether there is an upgrade, patch etc, and a location to download it from. In a company domain, just use AD, as has been said.
"The problem is that it can't be done from within the program since the program cannot be running when the installation/upgrade is taking place."
Why? Windows Installer will show FilesInUse dialogs for the end user to close down the running app. So this situation is already dealt with, and I'm not sure where you see a problem.
"...and if it could suspend the program to do the necessary checks and updates and only than to restart the app."
This is exactly what Restart Manager is for. Integrate your app with RM and Windows Installer will allow you to close down the app (saving whatever data you need to recover) and then restart you afterwards so you can recover your data and the user sees a minimal interruption. One example:
http://www.codeproject.com/Articles/772868/Restart-Manager-Support-For-Windows-Application
So I think TomTom's point is valid - there is no need to re-invent what AD does, or worry about how to update programs that are running, or how to restart a program after an installer update because all these problems were solved years ago.
My application is installed on ATM-like machines arouns the world.
It is a WPF application which needs to be automatically updated behind the scenes and without user interaction at all.
Right now we're using Click-Once silent install API and it works perfectly. Our current functionality keeps checking constantly behind the scenes if there is a new version and if such exists, it updates the application, waits for the machine to be Idle (untouched by any users for 5 minutes) and only then it restarts the app. After the restart, a new version is loaded.
Is there a way i can achieve all this using MSI's ? Here's a summary of what i need:
Remote and silent updates for all machines - i already know i can achieve this using LogMeIn and MSIEXEC (so no need to answer this bullet)
Update the application while it is running, without restarting it.
Restarting the application and running the new version only when the application is Idle for 5 minutes.
Any suggestions? If not MSI then any other installer perhaps?
I Can't use clickonce because i want to set my application as the Shell (instead of cmd.exe) in Windows Embedded 8.
It's an interesting high availability story and I can' think of a way to solve it and while MSI will work, it's not really an installer problem per say.
I'd create two installers: ContentManager and Application
The CM once finished should hardly ever change. It's job is to check for available updates and the idle status of the application. When an update is available and the application is idle it can perform a new silent side by side install of application in the background. Note I said install not upgrade. Now you have 2 versions of application installed. When the old application is still reporting idle it could be shutdown and the new version launched.
This would be highly available and MSI wouldn't need to know anything about the scenario. It's simply performing an install.
If you don't need it quite this highly available, then the other thing to consider is that Windows Installer supports "Restart Manager". Your WPF application can also. Your application could check for updates and start an upgrade. The restart manager interaction would then stop and restart your application during the upgrade.
The nice thing about the HA solution is your old version is still there. The content manager could back out the change simply by running the old version of the application.
#Christopher Painter, Thanks for your response. A few thoughts:
The High-Availability solution is good at its base but it would require us to implement too much stuff on our own. A few things you haven't mentioned for such scenarios: 1. what happens if a download fails, what happens if the unzip fails, i would need to uninstall the previous version once install is complete, i would need to implement some security measures on my own (hashing for the 'version xml' or something like that...) how about shared resource locking? i would need to handle it on my own as well... Click once handles all this stuff nicely. Oh and one more thing i'd like to avoid is maintaining two applications instead of one as you suggested. I can't count on the 'Manager' so much that i wouldn't support updating it remotely. I can, however, use a 'push' methodology to activate the MSI using LogMeIn - It lets me upload and send a command to all machines (AMTs). The Restart Manager solution would work for me. Only thing i still haven't figured out is if i can make it hault until the application is Idle, and for how long (it must have some sort of a timeout). I've also researched MSI Custom Actions which can wait on a shared mutex ('idle'). What do you think?
At the office, when I leave for the night I very rarely log off or reboot. I simply lock my workstation and go home, leaving all my development tools exactly how I left them.
If Windows-Update rolls through and reboots my machine in the middle of the night I'm only slightly peeved because when I log back in the next morning, any MS Office application, or Visual Studio instance I had running will have already automatically restarted, opening whatever file(s)/projects/solutions I may have been working on.
My question is: How can I make my Windows Forms applications (C#) do this? Is there some way for my application to "register" that it wants to be restarted if the system automatically reboots?
I think the RegisterApplicationRestart Win32 API function might be what you're after, it's part of the Restart Manager API.
If you have Windows Vista or Windows 7, you can use the Managed Restart and Recovery API. The links on that page also point to some useful blog entries
http://channel9.msdn.com/posts/DanielMoth/Windows-Vista-Restart-amp-Recovery-APIs-from-managed-code/
A simple way is to add an entry to the following registry key :
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce
Just create a value containing the path of your app (optionally including command line arguments). The app will be run at the next startup, then the value will be deleted.
Step 1: Figure out a way to differentiate a windows-triggered restart from a standard one. One solution would be to try preprocessing messages. They're probably different for a windows-triggered restart...or at least they are in Vista in some cases :/
Step 2: If you detect it's a windows-triggered restart, add a scheduled, one-time task.
Okay I've spent the afternoon researching and haven't had much luck finding the answer to this. I am trying to prevent an application from launching via some sort of dll or background application. It is to be used in monitoring application usage and licenses at my institution. I have found leads here regarding WqlEventQuery and also FileSystemWatcher. Neither of these solutions appear to work for me because:
With WqlEventQuery I was only able to handle an event after the process was created. Using notepad as a test, notepad was visible and accessible to me before my logic closed it. I attempted to Suspend/Resume the thread (I know this is unsafe but I was testing/playing) but this just hung the window until my logic finished.
With FileSystemWatcher I was not able to get any events from launching a .exe, only creating, renaming and deleting files.
The goal here is to not let the application launch at all unless my logic allows it to launch. Is this possible? The next best solution I came up with was forcing some type of modal dialog which does not allow the user to interact with anything, once the dialog is closed the application is killed. My concern here is killing the application nicely and handling applications with high overhead when they load such as Photoshop or something. This would also interfere with a feature I was hoping to have where the user could enter a queue until a license is available. Is this my best route? Any other suggestions?
Thanks
edit: To clarify this is not a virus or anything malicious. It's not about preventing access to a blacklist or allowing access through a whitelist. The idea is to check a database on a case by case basis for certain applications and see if there is a license available for use. If there is, let the app launch, if not display a dialog letting the user know. We also will use this for monitoring and keeping track if we have enough licenses to meet demand, etc. An example of one of these apps is SPSS which have very expensive licenses but a very limited pool of people using it.
Could you use
System.Diagnostics.Process.GetProcessesByName
in a loop to look for the process?
It might work if you don't use too aggressive a polling rate.
You are indeed close, take a look at the WMI Management Events. http://msdn.microsoft.com/en-us/library/ms186151%28VS.80%29.aspx
Sample code from Microsoft: http://msdn.microsoft.com/en-us/library/ms257355(VS.80).aspx
Subscribing to the appropriate event will provide your application with the appropriate information to perform what you described.
Not sure if this is a GOOD solution but you could do something like pass a key into main so that if the key is not present or valid the application shuts down. Then when you open the application in your code, just pass the key in. Someone would then have to know the key in order to start the application.
This is assuming you have access to the application in question's source code, which upon reading your question again, I'm not so sure of.
I assume you don't have source for the application you want to prevent from loading...
Have you considered using a system policy? That would be the best-supported way to prevent a user from launching a program.
You could have a service running that force-kills any app that isn't "whitelisted", but I can't say how well that would work.
I wonder if you are taking the wrong approach. Back in the day there was a Mac app that would prevent access to the desktop and had buttons to launch a set list of applications.
IDEA
What if you had a wrapper for the approved apps then only allow your wrapper to run on the computer?
I would expect there is some way of hooking an application launch, but can't help directly on that front.
You may be able to improve your current approach by detecting the application's window opening and hiding it (move it offscreen) so that the user can't attempt to interact with it while you are trying to shut it down.
However, another approach that may be possible (depending on your circumstances) would be to write an application launcher. This simply is a replacement for the shortcut to the application that checks your licencing conditions, and then does a Process.Start to launch the real .exe at that point. This would work well for any application. (I used a system like this for starting up applications with specialised environment settings and it works beautifully)
You could combine this with your current approach as a fall-back for "clever" users who manage to circumvent your launcher.
If my understanding is right you want to create an application what will prevent the computer user to start any other process except ones for a white-list.
If this is the case, monitor the process list of processes (in a while loop) using System.Diagnostics.Process (the GetProcesses method gives the list of all running ones)
Just kill the process when it starts.
Or if your machines have Windows 7 (Windows 2008??) you can use AppLocker. http://www.microsoft.com/windows/enterprise/products/windows-7/features.aspx#applocker Just let Windows prevent the startup.
You might want to look at this product: http://www.sassafras.com/licensing.html Personally I can't stand it, but that's because it does what you describe. Might save you some coding.
You could actually edit the registry so when you click a psd, your launcher gets called instead of photoshop. Your launcher then checks for licenses and if there is one starts photoshop with the path of the file.
This is a long shot but you may find it helpful.
Perceived Types and Application Registration
http://msdn.microsoft.com/en-us/library/cc144150(VS.85).aspx