When I try to upgrade my current WP7 project to a WP8 version using VS2012 built-in feature "Upgrade to Windows Phone 8.0"
I received an error message:
Upgrade to the project could not be completed.
Object reference not set to an instance object.
This error has little useful information to work with, how to solve it?
If you want run app in WP 8 devices, perhaps you'll have a problem with the screen resolution on devices HTC. The best way is create new WP 8 project and share (add as link) most of the .cs and .xaml files of your WP7 project. I did it guided by the article http://www.developer.nokia.com/Community/Wiki/Maintaining_a_WP7_and_WP8_version_of_a_same_Silverlight_application
Good luck!
Related
I was trying to add a web service reference to a Xamarin.Forms app when I noticed that there was no "Add service reference" option available when right-clicking the project's References. After some digging around I found that apparently you cannot add a web service reference to a project that targets Windows Phone 8. I am fine with removing Windows Phone 8 from my app as I really only care about Android and iOS. However, when I try to actually remove it, there doesn't seem to be an option to choose whether or not I want to target WP8 as you can see in the picture:
So how do I actually remove Windows Phone 8 from my app?
Thanks in advance.
Removing all Xamarin.xxx targets then uninstalling Xamarin.Forms from PCL and finally adding Xamarin.Android and Xamarin.iOS targets again seems to fix the problem.
I'd created a Windows Phone 8.1 Project into an existing Xamarin Forms solution (Android, iOS and UWP). I'd followed instructions from Xamarin Documentation pages, but still unable to find "LoadApplication()" method. I'm using Visual Studio 2015, and the Project has .NET Framework 4.5 on her profile.
The Xamarin.Forms.Platform.WinRT namespace hasn't the necessary class.
I have tried to create windows phone 8.1 client project following "Adding a Windows Phone App". It is working pretty well. You may miss some key procedure.
I have tested if you miss step two(right-click on the newly created project...)and step five(Edit MainPage.xaml...) in the article mentioned above, you will unable to find LoadApplication() method.
The code sample has uploaded to github,You could refer to my code sample and verify difference between this two. So that you could find the missing procedure.
I' am in a bit of truble at the moment.
I try to build my Xamarin Windows Store App for publishing, but the Create App Packages Wizard, wont open I tried many solutions from the web, like unloading and reloading the project, or making a new project. But the wizard does not open with my solution i treid a normal Windows Phone app(no Silverlight), that worked but i could not Port my xamarin project to a standard Windows Phone App.
Has someone encountered a similar issue with Xamarin and Windows Phone,
or can anyone help to get my app into the Appstore?
Thanks.
I would have asked in the Xamarin Forum, but I cant reach them siche this morning.
And sorry for the engrish.
To submit package to the windows phone store you'll need to build your project (for ARM in Release mode to avoid warnings). Then on developer site when there is button to upload package you have to attach *.xap file from your project's bin\release folder (or bin folder you have specified). Then you can go through the next windows phone store app submitting steps.
I had developed one application for WP8 devices(Target OS is WP8) in VS 2013 with WP8.1 SDK.Now I need to give support to WP7 also.Can I use WP7 SDK on VS2013 and develop app for WP7.So, I will create 2 apps for WP7 and WP8 and upload both on store.
What should be better solution?
Thanks.
I've encountered this problem several times, unfortunaly VS13 does not cooperate if you want to work with WP7 projects.
So if you really want WP7 apps, which I would reconsider since the marketshare is relatively small and I'd guess that people who download apps already have newer versions. Don't forget that lot of features may not be suported and you'd have to come up with new solutions..
Anyway, in case you decide to create WP7, dowload VS12 Express for example, create WP7 project and then copy files from your WP8 and see what works and what not.
You can open an existed project of WP7 using VS2013, but can't create new project by it.
When you create a new project in VS2013, it can only be WP8.0 or 8.1.
I have an existing Windows Phone 7.0 RTM app that was created using the MVVM Light project templates. After upgrading the app to Windows Phone 7.1 RC, I cannot preview the app in the emulator. The emulator appears to attempt to load and closes with the following error:
The object invoked has disconnected from its clients.
Does anyone have a workaround for this? I like MVVM light. I think it makes building the UI faster. At the same time I would like to use Windows Phone 7.1 RC because from what I understand it can connect to my WCF Data Service easily (without a 3rd party component e.g. http://odata.codeplex.com/releases/view/54698)
MVVM Light works well on WP7.1 SDK but you should upgrade the MVVM Light libraries in your app.
As you've already got an app that works on WP7.0, the easiest way to get hold of these is probably to get the MvvmLightLibs project from NuGet (Link here).
I'm not 100% sure this will fix your issue, but I'm fairly confident. You might also need to remove the old MVVM Light binaries to get your app to run properly...