I want to know what are the differences between a WPF Browser Application and WPF Desktop Application. I know that the browser application runs on IE and FF, but about the technology, is the same? I mean, we can do exactly the same by the two ways? (Of course, maybe with different UI)
I have this doubt because I'm looking for a book about WPF Browser Applications, but I only see books about WPF (I don't know if is in general or is only for desktop applications :S)
A WPF Browser Application uses exactly the same framework as a WPF desktop application and could run with the same UI, but with restrictions on trust which means that some APIs are not available. There a number of challenges in developing Browser application. A Browser app must be signed with a certificate. Some of the trust restrictions are not enforced at compile time and are only discovered at run time.
In the time since Browser Applications were first introduced, Microsoft developed Silverlight which uses a similar though not identical XAML technology. Silverlight is easier to deploy than a WPF Browser Application and may be appropriate depending upon your requirements.
A Browser Application not only runs in the browser but also with less authority. If you need to read and write local files then go WPF. Browser is good is you want rapid deployment to lots of PCs. Other wise I will take WPF Desktop every time. Most WPF books with have a chapter on XBAP. I like McDonald from Apress.
Related
I am reading about out of browser silverlight applications and cannot think of many use cases for it. One only scenario i can think of is where your application need ability to work offline and when its online then it can synchronize with the server ( or something). But in that case I can simply have a WPF ( or old style Winform) application that is communicating with server. Can anyone help me understanding better uses case for these out of browser applications.
There are some good answers on SO that should give you some background on Silverlight OOB vs. WCF:
Silverlight OOB vs WPF ClickOnce
What are the advantages of silverlight out of browser over wpf or vice versa?
I will add that as a corporate developer Silverlight has its benefits over WPF or WinForms in that there is no need to install the full .NET Framework to run the applications. OOB gives a more desktop like feel w/ Start Menu icons and easy access w/out the need of visiting a URL to run the application. There are a few things that you can do in elevated trust in OOB that you can't do in the browser (though that is changing w/ full trust rights both in-browser and OOB in SL5).
Here's some of the details on the features you get access to w/ elevated trust:
http://msdn.microsoft.com/en-us/library/ee721083(VS.95).aspx
It really comes down to your usage scenarios, ease of framework deployments and the environment you are developing for. Each set of tools has its benefits and drawbacks.
I have been using WPF for a while, and I keep on realizing again and again that Microsoft invests its efforst in Silverlight, not in WPF (RIA Services, default theme, controls and more).
I thought it might be a good idea to migrate to Silverlight (i.e. creating standalone desktop apps with Silverlight 4.0), the question is whether this is possible or not.
BTW, I think LightSwitch applications are generated with Silverlight as standalone desktop apps.
From MSDN:
Silverlight 3 applications are no longer restricted to running in a browser. They can be run in a browser or it they can be detached from the browser and run from the desktop. These out-of-browser applications allow you to bring the richness of Silverlight 3 applications directly to the desktop without the restriction of running within a browser.
Link: Building An Out-of-Browser Client With Silverlight 3
It is possible to create standalone desktop apps(Out of browser apps) with silverlight version 3.0 or higher and it works great. Now it is also possible to install the out of browser app even without opening a browser as shown at this blog post .Silverlight is awesome and silverlight apps even run on MACs and Linux(limited support)
However, it is not true that Microsoft is only investing in silverlight. Microsoft is investing in WPF too. Though it is possible to create out of browser applications with silverlight, they have lot of limitations when compared to a full blown WPF applications.Dont forget that silverlight is just a subset of WPF, for example, silverlight doesnt have ADO.NET, Hardware device access etc. So if your application is merely a business application and you dont have to access hardware devices or database directly then silverlight might be an option, however if your application accessing client machines hardware resources directly then you are better off with WPF.
My suggestion is, If you know before hand that it is going to be a desktop application then go with WPF(or may be even XBAP). In my experience, useful applications grow with time, new features are always requested time to time. If in future,a feature is requested that cannot be accomplished with silverlight and can only be accomplished with WPF, then you will be in a big trouble because you need to rewrite your app in WPF and it will be hard for you to convince your CFO to allocate more fund just to implement one feature. Silverlight is not designed to develop desktop applications, its main goal is multi-platform support.
Silverlight 3 supports Out-of-Browser functionality.
Quote from Wikipedia silverlight page :
Silverlight 3 supports Out-of-Browser experiences, i.e., Silverlight applications can be installed to the system for offline access (provided the application manifest is designed to allow local installation) where they run outside the browser.
Also here is a quick howto
Out of browser applications have the same security restrictions as in browser applications.
With Silverlight 4 you can create full trust applications which have full access to the computer.
More on Network Security Access Restrictions in Silverlight
If you mean Out of Browser apps, certainly. The Seesmic Desktop 2 app is an excellent example of one of these apps, with it's own updating mechanism. Seems a no brainer to use the XAP/MEF plug-in Model and Silverlight in this manner.
Seesmic Desktop 2
We're developing an OOB app along the same lines, one internet download and you're done. You're not going to get exactly the same APIs as you get in WPF, though.
As others have pointed out, Silverlight apps can be installed to run 'out-of-browser', but even with elevated trust they still have significant restrictions on what they can do and certainly don't have "full access to the computer".
Creating an app from scratch, you may want to consider parallel Silverlight & WPF builds. The code can more-or-less be shared by adding the .cs files from one project (e.g. WPF) to the other (Silverlight) using "Add As Link". The XAML files cannot be linked this way and need to be duplicated, but that may not involve much more than copying & pasting, depending on your structure. There're good examples of this on the web.
Developing both types in parallel would likely involve a lot less effort than having to abruptly switch types at some point and discovering incompatibilities/limitations too late.
For the experienced WPFers out there, how re-usable are WPF, Silverlight and Silverlight OOB applications and components? How much overlap is there?
For example, could I write one application and easily deploy it in the three aforementioned ways?
Ideally, I want to write as little code as possible and have the flexibility of deploying it in a range of scenarios, maybe enabling certain functionality depending on deployment. The WPF family of technologies seems like a good starting point to the casual observer.. but is it really?
The simplified version of the answer is:
1. Silverlight is roughly a subset of WPF.
2. Silverlight in browser apps and Silverlight OOB apps are running on exactly the same framework. It is just a deployment difference.
3. Some OOB apps can be installed as "trusted" apps, and have looser security restraints than in browser apps.
Porting a WPF app to Silverlight is likely going to be very difficult, as a WPF app is likely to use many features of the .net framework that are not available in the smaller subset of the framework available to Silverlight apps. This is something you probably want to avoid.
Porting a Silverlight app to WPF is likely to be significantly easier. It would still be a challenge as there are features in Silverlight not in WPF (though not nearly as many as the converse). In addition to the feature delta, the actual framework that runs the Silverlight/WPF apps are different, so during the porting you would likely run into a certain amount of behavioral differences between the two.
Silverlight and Silverlight OOB apps are running on the same framework. It is possible to have the exact same app binary run in both places. For the most part, they will be behave identically. Some differences: in-browser apps can rely on browser features such as accessing the html dom, invoking javascript, etc. An OOB app doesn't run in the browser so obviously this doesn't apply. Also, if we are dealing with a "trusted" OOB app, it can do things that are prevented for security reasons in the browser (e.g. COM interop).
If you want to create an app that runs in all three places, my advice is to start building the app as an in-browser Silverlight app that is self-contained, i.e. it does not rely on the web page that is hosting it, and includes all the necessary resources inside the xap package (rather than relying on them being next to the package on the web server). Porting such an app to a Silverlight OOB app would be a cinch - pretty much just check a box in Visual Studio and you are done. Porting it to WPF would be a significant amount of work, but it would be much better than going the other way.
This question already has answers here:
Why change from WPF to Silverlight 4?
(8 answers)
Closed 3 years ago.
If I understand correctly, Microsoft Silverlight is a lightweight .NET implementation meant to run on the client side, inside a browser. So now I hear about "out of browser" silverlight applications and I'm confused.
What is the advantage of an "out of browser" silverlight application, compared to a traditional .NET desktop application?
An out-of-browser install of a Silverlight application still runs in a security sandbox where as a traditional .NET desktop application won't.
The objective of an OOB is to give the user the ability to lift a web-based application out of its browser container and make it easier to access. Its still a web based application. Its worth bearing in mind that this works on a Mac where as a traditional .NET desktop app won't.
This area has become muddier with SL4 OOB that can now ask the user for elevated trust. Now the sandbox is more relaxed and there are greater opportunities to work with the native OS. However there are still many restrictions in place primarily to support multi-platforms. It would not be desirable if it became a defacto that trusted OOBs tend only to work on Windows. It remains to be seen whether that can be avoided.
So if you're thinking of a full-fledge Windows desktop app then you're probably better off using WPF. On the other hand if you don't need full access to the OS, you can deliver via a web page and/or you want to be able run on both Windows and Macs (and possibly other platforms) then perhaps Silverlight 4 OOB+Elevated Trust may be what you need.
Silverlight 3 out-of-browser apps allow any Silverlight app to have a desktop shortcut, and don't require the browser to be opened to run the app (so technically you could now run the app even if you're offline, since you don't have to fetch the SL app via the web).
With SL 4, you can now have elevated privileges, allowing the SL app to access local resources (such as the network stack and file system).
There's also a simple API call for an out-of-browser SL app to check for updates on startup, and download an update from the server. This could be seen as similar to click-once deployment, but it happens automatically and quickly, so it's more efficient and straightforward than click-once.
Compared to a traditional .NET app (in this case let's compare with WPF, since that's effectively the WinForms replacement), there's very little in the way of installation. No setup program, just the xap file, easily hosted on the web and very quickly installable. SL uses a reduced .NET framework, which might seem like a negative. However, the typical pattern for an SL app is to put most of the heavy-lifting in a service tier. Then, in the service tier you have the full .NET framework and can do pretty much whatever you want (such as accessing databases with ADO.NET).
Libraries are another thing to consider between the two applications. For example, Silverlight 4 natively has built in support for talking to a web-camera and microphone out of the box while WPF and the full .net Framework have a very large third party community of libraries to draw upon which you might need source code for if you wish to rebuild them under Silverlight.
Another factor is limitations in the sandbox, for example, you wouldn't be able to write an application that could connect to any server using any socket in Silverlight 4.
Can I use Silverlight to build cross-platform desktop widgets?
Silverlight Vs WPF
First of all, WPF is not exactly Silverlight. They essentially require different run times. Silverlight Runtime is a subset of .NET, and needs to be installed by the client, to view your SL applications over a browser. Presently SL runtime is available for Windows and Mac. Moonlight is still not full fledged, and is evolving, for Linux.
WPF, on the other hand, is purely on top of .NET runtime, and is available only for Windows.
You can use XAML to develop user experiences in Silverlight and WPF, and as long as you stick to the Silverlight subset, you can compile your XAML in WPF as well.
Desktop Widgets
Now, your thought about building cross platform 'desktop' widgets - Do you want to host a Silverlight application in a desktop window? Silverlight 3.0 provides support for hosting silverlight controls out of the browser.
Otherwise, see my blog entry on hosting Silverlight using a browser shell. http://amazedsaint.blogspot.com/2008/12/thinking-outside-silverlight-sandbox.html.
This post is revolved around
Hosting the HTML Page with Silverlight
in a Winforms/Webkit desktop application
using a web browser control, and
communicate to and fro using HTML
DOM
Embedding a light weight web server
with in the Host application, and
handle requests to perform such
operations
But remember - it is not WPF. Hope this clarifies.
In Silverlight 2.0, you won't have any such luck.
In Silverlight 3.0 (currently in beta), however, support has been added for Out of Browser Capabilities, which means you can download and run Silverlight apps from your desktop.
The Silverlight platform in general is cross-platform, so external (desktop) aplications in Silverlight 3.0 will be exactly the same.
Quoted from the What’s New in Silverlight 3 Beta? section of the release page:
Out of Browser Capabilities. The new out of browser experience in
Silverlight 3 enables users to place
their favorite Silverlight
applications directly onto their PC
and Mac, with links on the desktop and
start menu—all without the need to
download an additional runtime or
browser plug-in. Further, the new
experience enables Silverlight
applications to work whether the
computer is connected to the Internet
or not—a radical improvement to the
traditional Web experience. Features
include:
Life outside the browser. Silverlight applications can now be
installed to and run from the desktop
as lightweight web companions. Thus,
users can take their favorite Web
applications with them, regardless of
whether they are connected to the
Internet or not.
Desktop shortcuts and start menu support. Silverlight applications can
be stored on any PC or Mac computer’s
desktop with links in the start menu
and applications folder, and so are
available with one-click access.
Safe and secure. Leveraging the security features of the .NET
Framework, Silverlight applications
run inside a secure sandbox with
persistent isolated storage. These
applications have most of the same
security restrictions as traditional
web apps and so can be trusted without
security warnings or prompts,
minimizing user interruptions.
Smooth installation. Because Silverlight applications are stored in
a local cache and do not require extra
privileges to run, the installation
process is quick and efficient.
Auto-update. Upon launch, Silverlight applications can check for
new versions on the server, and
automatically update if one is found.
Internet connectivity detection. Silverlight applications can now
detect whether they have Internet
connectivity and can react
intelligently including caching a
users’ data until their connection is
restored.