Will applications working on wp7.5 work on wp8 also?
Yes, WP 7, WP 7.5 apps will continue to work on WP8, including apps using XNA framework. Although WP8 apps won't work on older platforms (which is expected).
Any of the existing WP devices will NOT receive the WP8 update. They will get the WP 7.8 update, which include the new start screen and 'user experience' but nothing else.
If you write an app targeting WP7.5, it will work on all devices.
UPDATE from BUILD 2012:
Windows Phone 8 SDK is now publicly available.
All your existing apps targeting WP 7 or WP 7.5 will 'just work'
You can update your apps to WP8 platform the same way you've used to upgrade WP 7 to WP 7.5, although this will make your app only work with WP8 devices. (AFAIK. can't confirm this.)
If you mark your app as a WP8 app, it will not work on WP7 or WP 7.5. Although you can mark the app as WP7.5 app, then you can use reflection to find the APIs you want, and call them (and degrade properly on a WP7.5 device where these APIs won't be available.)
In my opinion, reflection is messy, but you still have an option to support both using the same code, until WP 7.5 devices fade away. (You may have to take extra care when using reflection, because AFAIK there are some limitations to reflection on WinRT to avoid security and stability issues, which may be still true for WP8+)
Just as an additional information from my experiments with the currently available WP8 emulators and WP8 prototype devices. Not sure if the below will be changed in the final version:
Some UI controls for native Silverlight apps look different on the same WP8 emulator when app is compiled for 7.5 and 8. For example, check boxes look like WP7 when app is compiled to 7.5 and look more modern if app is compiled for WP8.
HTML5 apps and WebBrowser control. If your app is compiled for 7.5 it will continue to run old IE9 even on WP8. If you recompile it to WP8 the WebBrowser control will use IE10 with many improvements and optimizations. Confirmed by Microsoft WP IE team.
So there are some minor differences for WP7/8 apps run on WP8.
Related
If I target WP7 and WP8.1 then:
Will WP8.0 devices be able to download the WP7 version?
Will WP8.1 devices will get the WP8.1 version right ?
I'm developing an app I would like to target WP 7.1, 8.0 and 8.1.
I am thinking about targeting the 8.1 sdk for WP8. I am just not sure if that's a good idea right now as not all devices have gotten the 8.1 phone update.
According to my knowledge:
If your app is targeted to WP7 then it will be surely available for
Both the WP8 and WP8.1 until and unless you have not provided the
separate package for the later ones. so your first question's ans is
Yes
You said thinking about targeting the 8.1 sdk for WP8 But before
making this point explore that - Is it really worth or fruitful to do that
because what is New to WP8.1 will not be available for WP8 so
what's pushing you for doing it.
As you already mentioned that WP8.1 devices are very few. I think this should not be the point of making decision. What your decision should depend on is - Are you going to use new features of WP8.1 in your app or not. If you are doing then you should also target WP8.1.
Because in the end every single user should have better experience of your App.
If you are trying to use common code for the WP8.1 and Windows 8.1 then you can also check for Universal Apps and Difference between WP8.1 Apps using Win-rt Apis and WP8.1 Silverlight apps because their are significant differences between the later ones.
I have developed an app using PhoneJs framework for all mobile plateforms like Android, iOs, BleckBerry and Windows Phone. Now I came to know that PhoneJs doesn't support Windows Phone 7. I have to launch my app in next two days everything is ready except WP7. Can anyone suggest me some alternates for WP7 using PhoneJs. or how can I do porting for WP7.
While Windows Phone 7.x platform is not officially supported by PhoneJS, most apps will work, with partially degraded UI and performance. For example, I just checked the TipCalculator demo on HTC Mozart browser.
Packaging for WP7 can be done with PhoneGap Build.
I have some apps developed with Windows Phone SDK 7.1 which undoubtedly run on Windows Phone 8 without any change.
My question is the other way. If I upgrade my app WP7 apps to WP8, meaning I make necessary namespace changes and compile them with WP8 SDK, will they still run on WP7? - I guess no.
What should be my strategy to have apps that run on both of the OS and still I should be able to use advanced functionality (if it runs on WP8) that WP8 offers (like Wallet, NFC, Nokia Imaging and more stuff like that)?
Is that I need to create 2 separate versions of each app? One will run on WP7 built with WP7 SDK and will not have advanced functionality like Wallet, NFC Sharing. The other app will have all of them and built with WP8. Will they be two separate apps in Windows Phone Marketplace?
Windows Phone 7 apps will run on Windows Phone 8, but the reverse is not possible. The former is called backwards compatibility.
If you want to support WP 7 OS, you need to maintain two different applications and submit them independently to the store.
Since the release (and in some cases prior to) the release of Windows Phone 8, several WP7 apps on the marketplace have had updates that simply state "Updated for Windows Phone 8."
What does this mean, exactly? Because the marketplace allows multiple XAP uploads, is it a new XAP for WP8 but the app only allows a single description (thus "updated for WP8")? If so, does the marketplace push an update for WP7 even if the WP7 XAP hasn't changed?
Or, are there changes to the 7.1.1 SDK that optimize for WP7 apps on WP8? If so, could you provide a link outlining this? (I did a search, but all I could find is the 7.1.1 update targets 256MB devices.)
Bottom line, although I know WP7 apps are compatible on WP8, is there something I should be doing with my WP7 apps for WP8 while still functional on WP7?
Take a look at this, seems to be an issue that is being worked on at the moment.
http://social.msdn.microsoft.com/Forums/en-US/wpsubmit/thread/789b3017-d242-4151-9d0b-84c85c4b3c24
These tags of "Updated for Windows Phone 8" don't necessarily mean that the app has been upgraded to a Windows Phone 8 application. It could also mean that the developer has tested and fixed bugs that can break functionality for a Windows Phone 7 app in Windows Phone 8. For example, I found two bugs involving local storage in Windows phone 7 projects when running on Windows Phone 8. Therefore, I had to make some adjustments to get my project running 100% on Windows Phone 8 (but its still a WP7.1 project). For more information on bugs and "quirks" when running WP7.1 projects on Windows Phone 8 here is a link to Microsoft's information.
http://msdn.microsoft.com/en-us/library/windowsphone/develop/jj206947(v=vs.105).aspx
I must be doing something wrong when I'm doing my builds. I want my current update to be available for Windows Phone 7 and Windows Phone 8. I am using the WP8 SDK and targeting OS 8.
When I upload my XAP I get the AnyCPU.xap and now my app is only available on WP8. How can I make it available on WP7 as well?
DevCenter and the WP runtime works as following:
You can have one WP7 XAP and that could run on both WP7 and WP8.
-or- You can have one XAP for WP7 and one (or more) XAPs for WP8. The "or more" part comes in for multiple resolutions.
However, there's no way to take a WP8 project compiled in VS2012 and run it on WP7. You can't run WP8 XAPs on WP7. That's pretty obvious once we think about it since the assemblies being used in WP8 aren't available on WP7.
So, developers have to choose which code sharing model across WP7 and WP8 works for their app:
if your app only uses WP7 featuresets and looks OK on WP8 HD, use a WP7 XAP.
If your app only partially uses WP8 featuresets, create on WP7 XAP, and share the codebase to create WP8 XAP that lights-up with WP8 featursets.
And if your app must have WP8 featuresets (e.g. NFC or Bluetooth centric apps, etc) then you obviously can't target WP7 and can only submit WP8 XAPs.
Here's a print screen demoing the DevCenter support for submitting multiple XAPs for the same app on different platform versions and different resolutions:
For more information on how to target both WP7 and WP8 see this Nokia developer article. The article explains how to share code between WP7 and WP8 at runtime & compile time, what new features are WP8 exclusive and how to support multiple resolutions. I helped author that article so hopefully you'll find it useful. There's lots of helpful techniques that might not be obvious.
The Dev Center now allows you to have multiple xap files submitted for a single app.
So you can have one version submitted targeting 7.* and others for 8.*. E.g.
This allows you to target both platforms from one app.
You need to reupload the XAP file with Target Windows Phone OS Version in Visual Studio project properties set to Windows Phone OS 7.1