Xamarin.Forms provides a way to quickly build native apps for iOS, Android, Windows and macOS, completely in C#.

Read more about the platform at https://www.xamarin.com/forms.

Platform/Feature	Package name	Stable	Prerelease	Nightly Feed Azure (master branch)
Core	Xamarin.Forms
AppLinks	Xamarin.Forms.AppLinks
Maps	Xamarin.Forms.Maps
Maps.GTK	Xamarin.Forms.Maps.GTK
Maps.WPF	Xamarin.Forms.Maps.WPF
Pages	Xamarin.Forms.Pages
Pages.Azure	Xamarin.Forms.Pages.Azure
Platform.GTK	Xamarin.Forms.Platform.GTK
Platform.WPF	Xamarin.Forms.Platform.WPF
Visual.Material	Xamarin.Forms.Visual.Material

If you want to use the latest dev build then you should read this blog post:

• Add the nightly feed to your NuGet sources or add a NuGet.Config to your app (placing it in the same directory where your solution file is) with the following content:

  <?xml version="1.0" encoding="utf-8"?>
  <configuration>
    <packageSources>
      <clear />
      <add key="xamarin-ci" value="https://aka.ms/xf-ci/index.json" />
      <add key="NuGet.org" value="https://api.nuget.org/v3/index.json" />
    </packageSources>
  </configuration>

  NOTE: This NuGet.Config should be with your application unless you want nightly packages to potentially start being restored for other apps on the machine.

• Change your application's dependencies to have a * to get the latest version.

VS 2017+ is required for developing Xamarin.Forms. If you do not already have it installed, you can download it here. VS 2017+ Community is completely free. If you are installing VS 2017+ for the first time, select the "Custom" installation type and select the following from the features list to install:

• .NET desktop development - In the Summary > Optional select .NET Framework 4.7 SDK, .NET Framework 4.7 targeting pack.
• Universal Windows Platform Development - In the Summary > Optional select the Windows 10 Mobile Emulator.
• Mobile Development with .NET - In the Summary > Optional select Xamarin Remoted Simulator, Xamarin SDK Manager, Intel Hardware Accelerated Execution Manager (HAXM)

The Android 7.0 Nougat API 24 SDK is required for developing Xamarin.Forms. It can be installed by using the Xamarin Android SDK Manager.

We also recommend installing Xamarin Android Device Manager This will use the HAXM tools installed above and allow you to configure Android Virtual Devices (AVDs) that emulate Android devices. If you already have VS 2017+ installed, you can verify that these features are installed by modifying the VS 2017+ installation via the Visual Studio Installer.

If you do not already have it installed, instructions to download and setup can be found here.

Because of current Multi-Targeting limitations with Visual Studio for Mac you will need to manually build/restore some projects before you are able to work on the Xamarin Forms solution.

Here are a few different options we've put together to help make this process easier

• Branches 3.5+ come with a Cake script target that you can use to build and open VSMac

./build.sh --target vsmac

• When working on an earlier branch that does not have the cake scripts then you can use the following [build.sh] script(https://gist.github.com/PureWeen/92c1e1aff0c257c3decf0bcb8d6e9296)

• If you don't want to run any scripts then

  • Open Xamarin.Forms.sln
  • Wait for VSMAC to finish restoring all projects
  • from the command line run:
    • msbuild Xamarin.Forms.Build.Tasks/Xamarin.Forms.Build.Tasks.csproj
  • Now you should be able to run and deploy everything. The only reason you would need to do this process again is if you clean the solution folder or delete the bin/obj folders that are part of the Xamarin.Forms.Build.Tasks.csproj

If you are on Visual Studio for Mac 2017 you will need to turn off automatic package restore (Visual Studio => Preferences => Nuget => General => uncheck the Package Restore box) before working on the Xamarin.Forms solution. This step is no longer needed with Visual Studio for Mac 2019

Upon opening the Xamarin.Forms solution, you will find that there are a number of errors and warnings under the Error List pane; you can resolve this by changing the filter of Build + IntelliSense to Build Only. At this point, you should be able to successfully build the solution.

By default, the Xamarin.Forms.Controls project does not have a configuration for various API keys to access certain features on each platform (e.g. maps). When building the solution the first time, a controlgallery.config file will be generated inside that project, which looks like this:

UWPMapsAuthKey:

You will have to obtain your own API keys for each of these services, inserted directly after the identifier (e.g. UWPMapsAuthKey:abcdefghijklmnopqrstuvwxyz). You can find out how to obtain each of these as follows:

• UWPMapsAuthKey at https://microsoft.com/maps/create-a-bing-maps-key.aspx

Due to the way that Android works, the maps API key cannot be injected at runtime. As a result, you will have to add this key to the MapsKey.cs file under Xamarin.Forms.ControlGallery.Android/Properties:

[assembly: Android.App.MetaData("com.google.android.maps.v2.API_KEY", Value = "INSERT_KEY_HERE")]

You can find out how to obtain a Google Maps API key here.

Make sure you have nuget.exe 4.0 or above and the latest dotnet core sdk (2.0.3). On macOS you should specify the platform in the msbuild command (/p:Platform=iPhoneSimulator)

msbuild /restore Xamarin.Forms.sln

To run the UWP UI Tests:

1. Install and run the Windows Application Driver.
2. Launch the Xamarin.Forms.ControlGallery.WindowsUniversal project to install the ControlGallery application onto your system.

You should now be able to run any of the UWP UI Tests.

We follow the style used by the .NET Foundation, with a few exceptions:

• We do not use the private keyword as it is the default accessibility level in C#.
• We use hard tabs over spaces. You can change this setting in VS 2015 via Tools > Options and navigating to Text Editor > C# and selecting the "Keep tabs" radio option. In Visual Studio for Mac it's set via preferences in Source Code > Code Formatting > C# source code and disabling the checkbox for Convert tabs to spaces.
• Lines should be limited to a max of 120 characters (or as close as possible within reason). This may be set in Visual Studio for Mac via preferences in Source Code > Code Formatting > C# source code and changing the Desired file width to 120.

• How to Contribute

We use GitHub Issues to track issues. If at all possible, please submit a reproduction of your bug along with your bug report.