I am developing a Xamarin Forms (PCL) application for IOS and Android Platform.
My Xamarin Studio version is 5.5.4 (Build 15). I am on stable channel.
My Xamarin Forms dll version is 1.3.0.6292.
I have also added a Xamarin Forms Labs reference from NuGet, v1.2.0.
Since yesterday, whenever i am building the solution, i get following error:
error : Error initializing task XamlG: Not registered task XamlG.
Any possible resolution for this error? I have tried clean and build multiple time. Even deleted the entire source code and redownloaded everything from source control but same error.
This error can occur if you have upgraded from an older version of Xamarin.Forms to a newer version. The underlying problem is that the wrong Xamarin.Forms.Build.Tasks.dll is being loaded compared with the one that the custo MSBuild Xamarin.Forms.targets file is expecting.
There is a bug in Xamarin Studio where the old build Xamarin.Forms build tasks are still used after the NuGet package has been upgraded. You can workaround this by closing and re-opening the solution.
However you say you have deleted the source code and downloaded everything again so it sounds like you have a different problem. It may be that your project is trying to use two different versions of Xamarin.Forms at the same time. I would look at your project files (.csproj) in a text editor and make sure they are all using one version of Xamarin.Forms. Check that they are all referencing a single version of Xamarin.Forms.targets and it is the same version.
This is silly.
I just recloned the project in a new fresh folder and build it from scratch and it worked. The more i am using Xamarin Forms, the more buggy and unbaked it seems. There are random issues which get fixed just by rebuilding the project. Or like Matt pointed in his answer below, by just restarting the studio. In my programming experience with different IDEs and platforms, only Xamarin seems to have these problems regularly.
Related
I'm building a new Xamarin Forms 5 app using VS 2022 17.1.1. Everything in the project appears to be up-to-date.
I've been working on this project for a while and never had this issue. All of a sudden it just appeared today. The last action I took was to install the Plugin.InAppBilling package, thought the package in question is not used by the Plugin.InAppBilling package.
The error is as follows:
All I can see is that the shared project is using System.Numerics.Vectors version 4.5.0 and it seems to be dependency of Xamarin.Essentials which is version 1.7.1 in my project.
However, the version number of System.Numerics.Vectors seems to be 2.0.5.0 in the Android and iOS projects.
I found the GitHub issue here but I'm not seeing any clear resolution to this issue. Even though it appears to be a warning, in my case, I can no longer run the app because I keep getting deployment error to the Android Emulator or actual device. It simply refuses to deploy my app to the device/emulator. So, it's really NOT a warning in my case. It's a show-stopper. I'm a bit surprised about how lightly the Xamarin Essentials folks seem to have taken this issue on GitHub.
Has anyone actually resolved this issue? If so, what's the solution?
BTW, in my case both the Android and the iOS projects are throwing this error/warning and both use System.Numberics.Vectors version 2.0.5.0 even though the shared project has version 4.5.0 installed as a dependency undre Xamarin Esssentials.
I'd appreciate some pointers on how to make this issue disappear. Thanks.
At first, you can try to update the Xamarin.Essentials package in the Android and IOS project with the nuget package manager to the version 1.7.1.
And then, if the error is still here, you can right click the reference and remove the reference of the System.Numberics.Vectors 2.0.5.0 both in your Android and IOS project. Then download the System.Numberics.Vectors 4.5.0 in the nuget package manager both too.
I am building a Xamarin Forms solution (containing an iOS library, an Android library and a .NET Standard library) in TeamCity.
I have just upgraded to Xamarin Forms 3.1.0.583944. The project builds without any problem locally, but on my TeamCity build server (Windows Server 2016), I'm consistently getting the following error:
C:\BuildAgent\work\f12265fda07473c1\src\packages\Xamarin.Forms.3.1.0.583944\build\netstandard2.0\Xamarin.Forms.targets(44,
3): error XF002: Xamarin.Forms tasks do not match targets. Please
ensure that all projects reference the same version of Xamarin.Forms,
and if the error persists, please restart the IDE.
I have tried downgrading Xamarin Forms, and rebooting the build agent. Neither of these has succeeded.
UPDATE: There is a new error:
C:\BuildAgent\temp\buildTmp.nuget\packages\xamarin.forms\3.0.0.561731\build\netstandard2.0\Xamarin.Forms.targets(44, 3): error XF002: Xamarin.Forms tasks do not match targets. Please ensure that all projects reference the same version of Xamarin.Forms, and if the error persists, please restart the IDE.
For some reason, the agent is looking for Version 3.0.0.561731. But that is no longer anywhere in the project. I had deleted the entire C:\BuildAgent\temp\buildTmp\.nuget\packages\xamarin.forms\3.0.0.561731 folder, but it has come back.
ADDENDUM: I notice that every time I upgrade Xamarin.Forms to this version via NuGet, it fails to uninstall the old package, and I have to restart Visual Studio to complete the process. This happens without fail. I am fairly sure this is connected to the breaking build, but that is more due to speculation and experience than concrete analysis.
I found out how to fix the problem, but it's not clear to me why it would manifest in the way it has -- locally and even when I RDP onto the build agent, it builds without trouble, but when I run the build agent from the TeamCity console I hit these compilation errors.
One of my dependencies is a NuGet package, which itself has a dependency on Xamarin Forms. Fortunately, I own that NuGet package, and was able to upgrade its Xamarin Forms version to the latest available package. If I didn't own that package I would be completely stuck though -- so this is only a partial solution.
The above answer was quite helpful for me . I would like to add a couple of additional notes though. I was facing this issue when I was using Xamarin Forms 3+ and my local build was being really inconsistent with the same error "Xamarin.Forms tasks do not match targets. Please ensure that all projects reference the same version of Xamarin.Forms, and if the error persists, please restart the IDE.". Then I cleared my local NuGet cache and rebuilt the project and saw that there were other NuGet package versions being pulled for Xamarin Forms when I did a NuGet restore. I then reversed the ordering of the NuGet packages starting with Xamarin Forms and it all worked fine.
I'm using Visual Studio 2017, and I stared a new Xamarin Forms app:
Create New project - Cross Platform App (Xamarin)
Blank App, and I chose Portable Class Library (PCL)
The app compiles and runs.
Now I right click the solution and choose Manage Nuget packages for solution, and it tells me I'm running version 23.3.0 and I should update to 25.4.0.1
After the update and 3 VS reboots, it gives me a host of errors I have been trying to solve for an hour including googling.
All theme related.
I tried removing the styles.xml file all together. I removed the theme from the reference to the theme from the manafest and it keeps putting it back.
I can't figure out what I'm doing wrong. I have not written any code.
Xamarin Forms requires a specific version of the Android Support libraries. Do not update them.
Delete your project and create a new one.
It is possible to get round this limitation by ensuring you are using a specific version of Android and by updating all Android SDK's, but for a beginner I would recommend just using the support libraries that are installed alongside Xamarin Forms.
In my project, I am using the Microsoft.EntityFrameworkCore.SQLite package from NuGet. But for Android 7+, the app crashes with unauthorized access to "/system/lib64/libsqlite.so".
This is because Android 7 doesn't allow native libraries other than the ones in their NDK (as far as I understood). Also see this issue: https://github.com/aspnet/EntityFramework/issues/7777.
So, I researched the internet for about 2 days now and unsuccessfully tried a bunch of things to get EFCore to work on Android 7. One of them was to update to the preview version v2.0.0-preview1-final. But this resulted in other problems like the following where the app compiled, but crashed while deploying/starting on the emulator:
06-21 09:58:18.970 D/Mono ( 3632): Assembly Loader probing location: 'System.Runtime.CompilerServices.Unsafe'.
06-21 09:58:18.970 F/monodroid-assembly( 3632): Could not load assembly 'System.Runtime.CompilerServices.Unsafe' during startup registration.
06-21 09:58:18.970 F/monodroid-assembly( 3632): This might be due to an invalid debug installation.
I then tried to add the 'System.Runtime.CompilerServices.Unsafe' NuGet package manually to my project, but it didnt fix the problem.
I messed around a lot, trying different build parameters and such and actually got the app running with the preview package of EFCore on an Android 7 emulator. However, after a project clean and rebuild, the error showed up again.
Any help on how to get EFCore Sqlite to work on Android 7?
I am using Visual Studio 2017 with Xamarin.Android 7.3.1.2
I created an example project in order to reproduce the issue: https://github.com/tipa/EFCoreSample - Basically just started with the basic Android template from VS and added the Nuget package
I know this was asked more than two months ago and you've probably found the solution, but I've wanted to post how we've managed to get around this issue.
We are developing a Xamarin.Forms application with EntityFrameworkCore and SQLite. Due to project and company policies, we are restricted to using .NetStandard 1.6 (we migrated our PCL projects from .NetFramework to .NetStandard in order to integrate EntityFrameworkCore).
After this issue started happening to us, we managed to fix this by doing the following:
Updating "Microsoft.EntityFrameworkCore" and "Microsoft.EntityFrameworkCore.SQLite" from version "1.1.1" to "2.0.0-preview1-final" (this is the latest version that works with .NetStandard 1.6) in the DAL project (we have a separate PCL project that contains the Context, UoW, Repositories and Models)
Updating just "Microsoft.Data.Sqlite" (this automatically updates the needed dependencies) from version "1.1.1" to "2.0.0-preview1-final" in the main Xamarin.Forms Android project
EntityFrameworkCore versions 2.x.x use the Android 7+ "approved" way of accessing the "libsqlite.so" file, while versions 1.x.x do not.
Hope this is of help to anyone who might use similar packages that we had.
I had the same issue and I found a solution to this problem.
I'm using Xamarin.Forms applications with .Net Standard 2.0 libs and using EFCore with SQLite. All you have to do is edit your Android csproj and add this after the last PropertyGroup tag:
<PropertyGroup>
<NoWarn>$(NoWarn);NU1605</NoWarn>
</PropertyGroup>
And then add the reference for System.Runtime.CompilerServices.Unsafe in csproj:
<PackageReference Include="System.Runtime.CompilerServices.Unsafe" Version="4.3.0" />
Clean and Rebuild your Android Project.
I found the answer to the problem here: https://developercommunity.visualstudio.com/content/problem/152947/xamarin-android-run-error-could-not-load-assembly.html
I using Windows 10 and am trying to create a Xamarin.Forms - Blank Xaml App (Xamarin.Forms Portable) project for the first time. I have Visual Studio 2015 Enterprise Update 3 installed and have tried uninstalling, reinstalling, and repairing multiple times.
When I create a project, I get the following errors:
"The name 'InitializeComponent' does not exist in the current context"
"Error encountered while loading the project. Some project features, such as full solution analysis for the failed project and projects that depend on it, have been disabled" - for App, Droid, UWP, WinPhone, Windows, and iOS
"The XamlCTask task failed unexpectedly..." - for UWP, WinPhone, Windows, and iOS
I tried this on my work computer and home computer and I had the same issues with both.
I have tried updating Xamarin.Forms nuget to the latest version and the created 36 errors with Droid. I also tried going to c:/users/[YOURNAME]/AppData/Local. Delete the Xamarin folder and that did not solve the issue.
I tried creating other Visual Studio projects that did not involve Xamarin and did not have any issues with those. I know the issue is with Xamarin (probably something with Android) itself, but I don't think that there is anything that I am missing from the install. I tried installing it by first installing Visual Studio, then going to Modify and adding Cross Platform. That didn't work, so I uninstalled then downloaded the Xamarin Installer. I had the same issues with both.
I created a blank Android App and that give me the warning - "aapt.exe" exited with code - 1073741849".
A blank app for iPhone does not give any errors or warnings.
Windows Phone does not give any errors or warnings either.
Any ideas of what I should check for so I can get this working?
Here is a picture of the error that I'm getting
Try updating to the latest version of Forms to get rid of the XamlC errors. Assuming you haven't updated, the template is using a modestly old version. As for the aapt error, if you have the N SDK preview installed, removing that should help. Alternatively, make certain that you have up through API 23 installed.