Opening IE through WCF - c#

I have a WCF service hosted in a Windows service.
This service the WCF have one metohd and in this method I have one important line :
Process Browser = Process.Start("iexplore.exe", hostUrl);
I install Windows service as local system, but when I'm trying to invoke that method, everything seems to execute, except that one important line... and IE didn't open.
I would like to add that the method itself is not in the service itself but in one of the service dll reference
Any idea why?

http://social.msdn.microsoft.com/forums/en-US/netfxbcl/thread/63a7d1ec-7077-489a-a250-f7422f04317b
" in order to get the service to actually show the UI, you'd have to set the service in Computer Management to allow it to interact with the desktop. In the services window in computer management, go to the properties of your service, and on the Log On tab, check "Allow service to interact with desktop" "

Since Windows Vista MS has been adding lots of security-related changed esp. in the area what Windows Services can/can't do. Anything "desktop-like" (printing, accessing network shares, using Office Interop etc.) is harder and harder to get working.
You should rethink your design since IMHO any "server-like process" (for example a WCF service) can be accessed in parallel by multiple requests and thus should NOT use processes which are NOT designed for this type of interaction... what happens if your webservice starts multiple IE instances that way ? Will IE behave as you need/expect it ?
IF you really really MUST do it this way you should have
a normal desktop process hosting the WCF service
OR
two processes, one your Windows Service and one running as a normal desktop process dealing with IE... these two process communicate via IPC

Under what user is the service running? Try running it under the currently logged in user, with privileges to interact with the desktop and see if that helps.
In general, its not a great idea to have services launching GUI processes. For example, what if no one is logged on. What if many people are logged on? Should it open in all sessions... etc. Have you considered exposing a simple (e.g. Net.NamedPipes) endpoint on your service, and writing a small client UI to interact with it?

Related

IIS vs Windows Service?

I have a C# application that needs to always be running. I originally planned on making this a windows service but I now have a requirement to make the application host a web admin console.
I haven't played with IIS in quite a few years so my question is this:
What would you recommend I use?
I've thought about making a windows service and embedding a web server such as Cassini but so far I'm not very happy with the open source web servers I've looked at.
Can IIS handle this? Do people use it for this type of scenario, and if so how?
This sounds like a job for two separate projects.
One is the original Windows Service. Windows Services are well suited for what you're doing.
The second is the Web Project that will be used to administer the Windows Service. This is the part that runs in IIS.
It depends on what you mean by always running. An ASP.NET web application deployed in IIS could very well be unloaded by the web server if there aren't any requests for certain amount of time killing all background threads. So if you want an ever running background thread it would be better suited to use a Windows Service. As far as the web admin is concerned, well, here you don't have much choice: ASP.NET in IIS. In order to do something useful those two applications should be able to find a common language to talk. So you could use a database to store the results into which could be used by both applications.
IIS will run your app on first request, not on server boot. So you will still need to run a service to ensure your app is always running.
You can use IIS as a webserver for your web admin part, and link your ASP.net app with your service by means of a configuration database (easy) or webservices (a little more tricky).
Windows and Web services are two very different creatures. A web service will expose external methods that you can implement against an application, while a windows service is an entity within itself. If you're planning on using this service on a timed interval to perform an operation, a Windows service would be the right way to go. If you use a web service, you will need to invoke the method you wish to run from a secondary application.
If you need to queue commands against your windows service, you could always create a database that was accessible by both your website and your windows service. This way you could send commands and query data between the two. Placing a web service in to serve as an intermidary between the two may be overkill.

Windows Application in future to be controlled over browser

I am writing a Windows application using C#. I am planning on later to allow it to be controlled over the intranet using browser also. So in future we should be able to control it both using the local interface or over the intranet from the browser.
Is there any pre-defined architecture which will allow me to do this? What are the methods of achieving this? I am new to C#/.Net.
EDIT:
The windows application needs to access the communication ports extensively, and needs to be pretty stable and would probably run for some days together.
Thanks...
I can't tell you if a specific package exists that would ease the development. But, if I were to attempt it, after Googling and not finding something already available and meeting my needs, I would likely make my application a WCF host. Create service entry points to accept control messages remotely. You would also need some well-know location where to register your application so the remote system could find it. You should be sure to provide the user with a way of disabling the application remote control feature.
Your host interface will need to run on its own thread to remain performant. Since you are new to C#, and presumably windows forms application development, you will need to read up on how to properly talk to the GUI controls from a non-GUI thread.
Alternatively, you may want to implement your application as two distinct units, one with a GUI that does all the user interaction. It would form service requests to send to the host portion (with no GUI). Your app could then operate locally or be controlled remotely.
One solution I have used in a similar situation has three parts :-
1) Win32 (local) Service
Manages the COM ports and does whatever is necessary with the attached hardware
2) WinForms/Console Application
Runs on the local machine and communicates with the local service via named pipes or TCP.
3) Web Server + Web App
Runs on local or remote machine & communicates with local service.
The local user can shut the WinForms application down and log-off without affecting the service or remote users.
The newest version of Silverlight (the version that ships with Visual Studio 2010) allows what Microsoft terms the "Out Of Browser Experience" (OOB for short).
This allows the user to set up the Silverlight application as a desktop application as well as running through a browser.
Rudi Grobbler has just blogged about how he went about setting this up on his PC.

Run an exe when machine starts

I have created an SMS application in .NET.
I wanted that the application should run when the computer starts, even before the user logs in.
Just like the SQL Server.
You need to create your application as a Windows Service. The linked MSDN page will provide full details.
Microsoft Windows services, formerly known as NT services, enable you to create long-running executable applications that run in their own Windows sessions. These services can be automatically started when the computer boots, can be paused and restarted, and do not show any user interface. These features make services ideal for use on a server or whenever you need long-running functionality that does not interfere with other users who are working on the same computer. You can also run services in the security context of a specific user account that is different from the logged-on user or the default computer account. For more information about services and Windows sessions, see the About Services section in the Platform SDK documentation in the MSDN Library.
You could consider making it a Windows Service.
You'll have to write a service. Start here...
Wrap your application in a Windows Service, using the .NET System.ServiceProcess namespace.
The System.ServiceProcess namespace provides classes that allow you to implement, install, and control Windows service applications. Services are long-running executables that run without a user interface. Implementing a service involves inheriting from the ServiceBase class and defining specific behavior to process when start, stop, pause, and continue commands are passed in, as well as custom behavior and actions to take when the system shuts down.
Use ServiceEx to make a service from your executable: http://serviceex.com/ , just write one INI file, you can choose if application's window is hidden or showed etc.

Call A Windows Service from a remote computer

I am going to be coding up a windows service to add users to a computer (users with no rights, ie just for authentication). (As a side note, I plan to use this method.)
I want to be able to call this windows service from another computer.
How is this done? Is this a tall order? Would I be better off just creating a Web Service and hosting it in IIS?
I have some WCF services hosted in IIS on the calling computer (they will do the calling to the proposed windows service). I have found that Hosting in IIS is somewhat problematic, so I would rather not have a second IIS instance to manage unless I need to.
(I will be using Visual Studio 2008 SP1, C# and Windows Server 2003 (for both caller and service host).
Thanks for the help
If you are thinking of hosting a web service in IIS just to communicate with an NT-service on that same machine, that is definitely more trouble than it is worth in this case.
As other answers have indicated you can make a WCF service with the operations you need and host that within the same NT-service that you want to interact with. You can easily secure this with certificates, or user accounts to make sure it is only controlled by the right people/machines.
If you need to control the NT-service itself, there are existing programs such as sc.exe to start, stop, configure, or query the status of your NT-service remotely.
However, you may want to consider seeking a solution without the overhead of creating an custom NT-service and a custom WCF service to interact with it. If you do, the Net User commands (sorry no link - new user limitation) or the AddUsers (see kb 199878/en-us) utility may be sufficient. If your remote "controller" can invoke these commands directly against the target machine you may not have to create any custom software address this need. Additionally you would have less software to maintain and administer on the target machine. You would just be using the built-in OS capabilities and admin utilities.
Finally, you will need to think about the security aspect, NT-services and IIS are usually run under very restricted accounts, many auditors would flip-out over any service running with sufficient permission to create or modify users locally, and especially on other machines. You'll want to make sure that the service could never be used to create users that do have more than the "authenticate" permission you indicated.
Edit: The net user command may not work against another machine's local users, but check out. pspasswd that along with PsExec to create users, should do what you need remotely.
Simply host a WCF service in the Windows Service. You'll then be able to call it remotely.
You can host a WCF service inside a Windows service. Take a look at the TCP binding (NetTcpBinding class). Both client and server will have to use WCF, but that doesn't sound like it will be an issue with your implementation.
Also, the section entitled "Hosting in Windows Services" in this MSDN article provides a walk-through of the process
If the windows service publishes a remoting interface then it can be accessed via that remoting interface.
Otherwise it's the same as accessing any other process running on a remote machine except that there may be some tools (e.g., sc) with built in support for executing against a remote machine (barring firewall complications).
Any IPC mechanisms applies; sockets, web services, remoting, etc...
You could expose a WCF service directly from your windows service. When you start up your windows service, in addition to spinning up any other background processes, you could create an instance of ServiceHost<T> for your service implementation. This would allow you to not only provide WCF access, but also avoid the extra instance of IIS like you requested, and provide TCP, Named Pipes, and WsHttp endpoints. This should give you some nice flexibility in the performance tuning arena, since it sounds like this service will be consumed internally on your network, rather than externally.
You could create a WCF service which will talk to your Windows service on the remote box. Host the WCF component in IIS (or however you'd like so that you can communicate with it) and then call the WCF component from your remote machine.

Windows Service vs Windows Application - Best Practice

When should I go for a Windows Service and when should I go for a "Background Application" that runs in the notification area?
If I'm not wrong, my design decision would be, any app that needs to be running before the user logins to the computer should be a service. For everything else use a background app. Is my decision right?
Moreover, if I need "admin privileges" for my background app, I would escalate using a manifest. Are there any other specific advantage of running as a service?
My general rules of thumb are as follows
If it needs to always run, it's a service.
If it needs to be run under a particular user account, Network Service, Local System, generally it's a service (or a COM+ application)
If the user needs some control over it, it's generally a notification area application.
If it needs to notify the user of something, it's a notification area application
The fun comes when you have the need to run something as a system account, but also interact with it. IIS is a good example of this, it's a service, but the administration is an application - it needs to be running at the startup, it needs access to particular things a user can't normal access (c:\inetpub), but the user needs to be able to start, stop and configure it.
I would design an application as a service if the applcation has a critical purpose and should never (or rarely) be closed. Windows services provide good crash-recovery options, good notifications (see the recovery tab in service property).
Also a good reason to use services is because they can run under any user ( so if you
deploy them on a server that you remote to, you can safely log out after starting the service without worring that the application will close too).
I also design services in combination with a desktop application that can interact with the service and can be used to monitor or reconfigure the service while running. This way you can have all the benefits of a tray application, in your service.
However, you should not abuse using services and only use them, as I said, for cirtical applications.
I believe your decision is almost right, however, I would add one more condition. Take for example the mysqld service (you have a choice in this case, but most people run it as a service). It's ran as a service because you want to access the service anytime through potentially multiple applications. It's important that it is responsive to all applications calling upon it, and itself, is not much of anything, other than waiting to serve other applications.
Just something I would consider as well when making my decision.

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