I've created two different Xamarin.Forms solutions from templates. The first one is created with Prism template pack (version 2.0.5) the other one is created with the built-in Xamarin template that comes with Visual Studio 2017 (15.5.0 Preview). Both solutions utilize .net standard 2.0 and build fine on all three platforms. Now to the confusing part. As seen in this image:
the Android-project references of the two solutions is quite different. Why don't the first project need all the references of that the second do?
Because the Prism Template Pack is using the CopyNuGetImplementations feature of NuGet. This means that your projects do not need to add the references again. They will automatically get any NuGet references you have added to the main XF project. Much easier to manage.
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I work with Xamarin.Forms in Visual Studio since a few years, and updated my IDE recently (VS v. 16.3.7). Now I realized something is missing: the Shared Project option.
When i go through the Wizard to create a new project the question if I want to use Shared Project or PCL(or NetStandard) is now missing (see screenshot below from VS 2017)
I do know that you can still create a Shared Project and add an iOS and an Android project manually, but this is just too cumbersome. My question really is: Is there a reason why Microsoft went on to push the PCL/NetStandard above the Shared Project strategy?
I am specially confused about this decision since already back in 2016 #miguel.de.icaza declared his favorite option (for most cases) was the Shared Project strategy:
https://tirania.org/blog/archive/2016/Jan-22.html
For me, the PCL is just too cumbersome for most uses. It is like using a canon to kill a fly. It imposes too many limitations (limited API surface), forces you to jump through hoops to achieve some very basic tasks.
I have installed VS 2017 15.9.14, on this version, Portable Class Libraries (PCLs) are deprecated. You could use .NET Standard instead. On VS 2019, the default is .NET Standard.
On Microsoft document, MS recommend .NET Standard 2.0 libraries over Portable Class Libraries.
For more, please refer to the MS docs. https://learn.microsoft.com/en-us/xamarin/cross-platform/app-fundamentals/code-sharing
My question really is: Is there a reason why Microsoft went on to push the PCL above the Shared Project strategy?
For MS announcement, PCL is deprecated, you could not find that when you create the project.
You could create the Shared project by File > New > Project > Shared Project template.
For more details, you could check the link below. https://learn.microsoft.com/en-us/xamarin/cross-platform/app-fundamentals/shared-projects?tabs=windows
Updated:
Is there a reason why Microsoft went on to push the >NetStandard< above the Shared Project strategy?".
For the old version of VS 2017, .Net Standard is an option of Shared Project strategy.For the latest version of VS, MS use .Net Standard as the default for Sharing Strategy.
Is there any doc where MS states why Shared Project is now deprecated/not available in the Xamarin.Forms project wizard?
PCL is deprecated. Shared Project is still in use, in my answer, I provide the second link about how to create the shared project.
Summarizing and adding to the answer by #WendyZang-MSFT:
I started a project using the Shared Project strategy around 4 years ago, and until now i have not found any issue/problem specific to it that would make me consider moving to .Net Standard.
Recently i went into the trouble of localization, and even that was possible using Shared Project without much hassle.
As mentioned above, after i saw that the latest version of Visual Studio 2019 was not offering the possibility of creating a Xamarin.Forms App as a Shared Project i got a bit worried thinking that i should migrate my solution. But the time hast passed by, and i just realized that MS encourages the use of .Net Standard, but Shared Project remains also a valid approach.
I am struggling with creating NuGet packages. I am using Visual Studio 2017 Community edition.
I have seen a couple of videos that show a "Pack" option on the menu when right-clicking the project in Solution Explorer. However, I do not have that option. Is this one of the features in the other (non-Community) versions of Visual Studio? I believe I have also seen a "create NuGet package on build" option mentioned somewhere. I cannot find that either.
I have tried various ways of using nuget, dotnet, and msbuild from the command line(s), but haven't had much success. Very frustrating.
Any help is appreciated.
If you really want to use Visual Studio, I would recommend installing an extension that helps you with that problem. For example, this one. The options people have in videos depend on the extensions they have installed. For you, it is the same.
Alternatively, just use the command-line tooling for this as explained here or for .NET Core here or here.
dotnet/msbuild pack is only available for SDK-style projects, but I believe works for all versions of Visual Studio, as well as on the command line. .NET Core introduced these SDK-style projects, which can be identified by <Project Sdk="Microsoft.NET.Sdk">. If your project (.csproj if it's a C# project) doesn't have the Sdk property or import Microsoft.NET.Sdk in either of the two other ways, then it's not an SDK style project and doesn't support packing in this way. Another obvious difference between the two styles of projects is that SDK projects are only a few lines long from the new project template and don't list files in the project, whereas old style projects are typically a full screen long, even from a new project template with only a single class file, and it does list individual files in the project. If you want to continue with this project type, you'll need to use nuget.exe pack and you'll probably want to create a .nuspec file to define some of the package metadata.
However, using SDK style projects is the future, it just takes time for all of Microsoft's existing project types to migrate. It's much simpler to use, so personally I would avoid old style projects unless you're using a project type (like ASP.NET, not ASP.NET Core) that doesn't support it.
All of this is confusing for anyone new to the .NET ecosystem. My recommendation is 1. when you install Visual Studio, when making your workload selections, make sure in the component list that .NET Core is selected, whatever the newest version of .NET Core that is available at the time of installation. When creating a new project in Visual Studio, always select the .NET Core version, or .NET Standard version of any new project template, even if you want to target the (Windows) .NET Framework, in which case you edit the .csproj and change <TargetFramework>netstandard2.0</TargetFramework> to <TargetFramework>net45</TargetFramework>, although I would recommend multi-targeting possible by adding a s to the element name and using a semi-colon separated list: <TargetFrameworks>net45;netstandard2.0</TargetFrameworks>. So, avoid the "Class Library (.NET Framework)" template, instead use "Class Library (.NET Standard)" and then change the target if you have to.
#zivkan led me down the right path. Changing my project types to .Net Core from .Net Framework made all the options I mentioned in my original post available. No extensions were needed.
My .Net Core class library project now has the Pack and Publish options available on the project's context menu. In addition, there is a another tab (Package) on the project properties page. On that page there is a "Generate NuGet package on build" option along with version, name, tags and other properties.
I have done much .Net framework development, but have been ignoring .Net Core and the newer options. I guess I need to dig in and learn about them.
My team has built a Xamarin.Forms application using VS2017. We are using a Shared project because one of our core functionalities requires ESRI mapping, and ArcGIS Runtime for Xamarin does not support anything but Shared projects at this time.
The next app that my boss wants should be fairly quick to develop if I can use the existing code we've already written for the first app. However, I don't see any way that I can reference that code from another project. I have tried adding a new UWP project to the existing one, but then I have to add all the same NuGet packages, 90% of which are unnecessary to this new project. On top of that, it won't actually compile correctly since the App.xaml is different.
I've searched all over trying to find a solution to this, and haven't come up with anything. PCL is not an option, nor is .NET Standard. Is there any way to accomplish this?
As the title says, is this currently an option? As can be seen in the screenshot, I don't see an option for creating a crossplatform project in Visual Studio. Is there a way around this i.e. is the cross-platform option just there for conveniently setting up the project structure? If so, how should I do this?
The references others have posted are good, except that not all those projects are .Net Standard 2.0, so if you use them, you will need to upgrade later. But even without a current template, creating a Xamarin Forms F# solution is not hard:
Create a new .Net Standard C# Xamarin.Forms project. Delete the .Net Standard C# library, leaving the platform-specific parts.
Add a .Net Standard 2.0 F# library, install the Xamarin.Forms package, and connect the platform projects to it.
Define an App class in this library:
type SomeNamespace.App() =
inherit Xamarin.Forms.Application()
do base.MainPage <- ...
Refer to this in the (C#) platform projects: LoadApplication(new SomeNamespace.App());
I'm trying to build an Android and iOS app with Xamarin using a shared PCL library. I'm following the tutorial on the Xamarin website [1].
I have created my PCL solution, which currently doesn't do anything, and I'm now trying to reference it from another Android solution.
The documentation indicates I should use References and then select Projects. However, when I do this, I can't either see or find a way to add my PCL library project as a reference.
How can I add my PCL library solution as a reference in another solution?
[1] http://developer.xamarin.com/guides/cross-platform/application_fundamentals/pcl/introduction_to_portable_class_libraries/#Using_PCL
A solution is just a container for one or more projects. One project can be included in multiple solutions. By including multiple projects in one solution you can reference them from one another, which will allow them to automatically build/update their dependencies when needed. You can add a new project to an existing solution by doing "Add New Project" in the solution explorer - you don't have to create a complete new solution for each project.