I am putting together a Silverlight 5 application that will run out-of-browser and has a bit of everything on start-up. Specifically, here are the steps I need to follow:
Check that the app is running out of browser (if not, display a screen instructing the user to install it locally).
Display a "splash screen" (it would be nice if this would play animations while the remaining steps execute).
Configure MEF
Pre-load context information and 'static' data from the server (for example, settings). This data is required before any of the application logic can run.
Dynamically load additional XAP files including an external theme library.
Replace the "splash screen" with the shell which contains a navigation frame.
Navigate to the application's start page.
I also need to support Application Extension Services (IApplicationService, IApplicationLifetimeAware) so any process I implement must respect these services. Most of these services will require MEF to be configured, so they should not execute before MEF has been configured and imports satisfied.
Another consideration is that some imports may be satisfied only after the dynamic XAP files have been pulled in and MEF recomposed.
One of the hurdles I'm running into is the fact that I cannot do step 5 until the previous steps are complete. Loading the XAP files or calling the server for data asynchronously allows the code to proceed. I need a way to "stall" the UI until all of the composition is complete and all required context data has been loaded.
So, I'm looking for recommended approaches that satisfy all of these requirements and am happy to provide more details if that helps get to a working solution.
UPDATE
The best explanation I can give for my difficulty is that I must 'release' the UI thread to display a 'splash screen' but also suspend the normal life cycle of the application while each step executes. I can't (and don't want to) do everything in the Application.Start event handler because application services will have already started.
Plus, releasing the UI thread means I do work in the background and let the original method (Application.Start, for instance) return and the runtime will move forward in the startup process. For example, starting a background process in the Starting method of an application service then returning allows the runtime to raise the Start event on the Application object. But if I need the background process to complete before I can do the next thing, I have to suspend the current thread which blocks the UI.
So I'm not sure how to divide up the work or where to put it (App, application service, bootstrapper, workflow, etc.).
You can use ManualResetEvent class to force the service calls to be Sync (and guarantee the order they complete). You could also use this to synchronize the background thread to the main UI thread.
http://mohundro.com/blog/2006/06/27/a-little-bit-about-manualresetevent/
Related
I have a code that is used in an Winforms application. The same code is also used in a Windows Service (exe running as Windows Service). The code grabs the handles to ICONs. But what I found is that, in Task Mangaer (and GDI View), when I ran the Winforms Application the app shows the GDI count. But when I ran the code via Windows Service, the service instance in Task Manager isn't showing any count for GDI. So, does this mean that Windows Service can never hold a GDI handle? If so, how does the code work, that is how is the code that runs on the handle actually working in Windows Service.
Services are in fact able to create and use GDI handles in exactly the same way as an ordinary application, except that the display surfaces are not visible to the user.
However, Task Manager is only able to query this information for processes that are in the same session that it is running in, and services always run in a separate session.
So, basically, just a false alarm. :-)
Is it possible to simulate multi developer scenario with RTC source control so that when I make code changes I can test accepting change sets for example. This is just so I can test a multi developer environment but using just one user.
I've tried creating multiple Eclipse workspaces, and loading the same project area into each Eclipse workspace. Using this method I am unable to accept change sets as RTC source control will just ask me to resync my workspace once I make a change in work Eclipse workspace:
It seems the only method of accepting incoming changes is to
1. Right click on the stream from within 'Pending CHanges' view
2. Select load
3. Select following option :
Make sure you use the Stream (ie make sure you don't deliver directly to another repo workspace simulating another user)
(Note: this is entirely different in ClearCase, where the "out of sync" can happen between the configuration of an UCM view and the one of a Stream after a rebase)
If you create different repo workspace (loaded in different Eclipse workspace), this can cause some confusion when used within the same Eclipse instance.
As said in this thread
repository workspaces are meant to isolate changes - being your private stream.
There is no automatic accepting of changes so you are in full control of what flows in. You can also run private builds on them. that is the whole idea.
If you want to run several repository workspaces with shared code you should use a Stream I think.
The clean repo workspace would be used to accept the changes you decide to deliver to your stream.
So you are trying to use a repository workspace as a stream. While they are almost identical, I am not sure about how they would react to changes delivered to them. Especially while being loaded.
You should use two Eclipse instances. I am concerned about having the same eclipse projects loaded multiple times in the same sandbox and the same Eclipse
That "confusion" is explained in the same thread:
This is expected behavior.
When you change WS1 by delivering to it, the content you've loaded to disk for WS1 isn't updated. So you have to reload.
For this reason, you are not allowed to deliver to other user's workspaces. You can't alter someone's workspace but you can alter your own because you would know why it went out of sync.
Check out point 7 and 10 of "Good practices and key workflows for Rational Team Concert Source Control users".
Note: the article "Loading Content from a Jazz Source Control Repository in Rational Team Concert 2.0" (also valid for RTC3.0) mentions in the section "Reloading Out-of-sync Shared Folders" a similar advice than the one given by the OP:
The local workspace can become out of sync with the remote workspace due to a couple of reasons:
The remote workspace is loaded multiple times and changes have been checked in or accepted from another client session.
An error was encountered during an operation (e.g. Accept) that modifies both the local and remote workspaces.
When the local workspace became out of sync with the remote workspace in RTC 1.0, the user was forced to run the Load wizard and reselect the folders that needed to be reloaded.
In RTC 2.0, this new option will automatically select the out of sync folders and reload them so they are no longer out of sync.
Also new in RTC 2.0 is an indication in the Pending Changes view that there are projects out of sync, as shown below.
Clicking on the Reload out of sync link in the Pending Changes view will open the Load wizard.
The reload option will be selected by default and clicking next will then allow you to select which folders to reload.
As you can see in the following screen shot, all the projects in the Foundation component are out of sync and need to be reloaded.
Clicking Finish will reload these folders and bring them back in sync.
Also the thread "How to handle project out of sync " provides an interesting illustration of that mechanism (even though it isn't exactly your situation).
I have a WPF application that loads modules into my application via prism / MEF. Each module will reference an assembly I created to house NHibernate functionality (Unit of Work & repository pattern). Now that I started on the first module, the following questions came up:
Is it common place to have an nhibernate session open for the lifetime of a WPF / windows application?
Would it be a good idea to share the nhibernate session amongst all modules or have each module create its own session?
It's my understanding that the session is lightweight, so opening and closing a session is not a problem... however, if I close the session then I lose the change tracking... when I call Save, and the object is the same as when it was retrieve, I do not want a query to be executed.
Do not have the session open for a the lifetime of a wpf/windows application. You will have performance and memory problems if you do.
It really depends how these modules interact. Are they separate systems, or do they need to work in tandem to do work. If it's the former, I would say that they shouldn't share sessions. If it's the latter, I would use some kind of session manager that can pass out the current session.
Hi I am evaluating ICUTest for use on a project. My initial view is that it looks like a promising Visual testing library. The scenario I have for using ICUTest is to start an application with a specific configuration and I expect the main application window to display based on the configuration settings. Each unit test should start the application and then after completing it should shutdown the application gracefully.
At the moment I can get individual tests to run, but when I run multiple tests I start running into all types of threading issues. Has anyone had any experience with this?
There are two ways to test your application.
1) The easiest (and most reusable) way is to just test your main app window like any other window. Do your initialization after a window event (like Window.Loaded) or through the constructor (e.g. new MainWindow("myapp.config") ).
2) If initialization must be done before the window is up then you can start the app thread with code similar to the one here.
Note: in WPF, you can only start an Application once, so method (1) is preferable.
Also, make sure you wrap all your GUI related calls in an ICU.Invoke(...) block.
I want a automatic update notification in my application. A message box should appear which tells that an update is available, if user wants then it can download the latest version in downloads folder of windows. Nothing else (user will install it manually) not application.
-I'm using Installshield so no Click once solution.
Thanks
If you want an out-of-the-box solution to this problem you're likely to be disappointed. I haven't found anything that works except ClickOnce, and I dislike it. I did find this:
http://windowsclient.net/articles/appupdater.aspx
My solution was to roll my own. It's actually not that difficult. I wrote a small bootstrapper application that first checks for updates, downloads them if necessary, and then launches my application in a new AppDomain. Pretty easy.
If you want to check for updates while your app is running, you need to write and add a component/class to your project that performs that task, and informs the user (MessageBox or whatever) that an update is available. If they choose to perform the update then you need to launch your bootstrapper (so it can fetch the updates) and kill your current process.
All of this is very possible with a little time and some custom code. It's not as difficult as it sounds. The biggest thing is determining how configurable you want your custom solution to be because that can affect when/where your bootstrapper goes to look for updates (I built mine to look for updates on a network share).
http://autoupdatewpf.codeplex.com/
i found one. This one is quite simple and solve the purpose.