xamarin-forms-book-samples

This repo has been archived. The samples are no longer current, or updated. However, they still make a great learning resource.

Sample code for the book Creating Mobile Apps with Xamarin.Forms. The book can be downloaded from https://docs.microsoft.com/xamarin/xamarin-forms/creating-mobile-apps-xamarin-forms/.

A handful of F# samples in this repo are available via the Microsoft code sample browser, but there are over 1,000 projects and the majority of them are only available by cloning the repo.

Notes

Loading the NuGet Packages

The Xamarin.Forms NuGet packages are not part of these projects. They must be downloaded for each project.

To avoid hassles, download the NuGet packages for the solutions in the Libraries directory first. You'll want to load each library solutions into Visual Studio, right-click the solution name in the Solution List and select Manage NuGet Packages for Solution. A notice might appear at the top of the Manage NuGet Packages dialog that says "Some NuGet packages are missing from this solution. Click to restore from you online package sources." If so, click the Restore button and then the Close button. Build the library.

Do the same thing with the other library solutions in the Libraries directory.

You can then load any of the application projects. For each project, again right-click the solution name, select Manage NuGet Packages for Solution and go through the same process.

The Branches

The original-code-from-book branch of this repository contains the code as it appeared in the Creating Mobile Apps with Xamarin.Forms book. The only change is that the projects have been updated to the latest Xamarin.Forms version.

The projects in the master branch reflect changes in C# and Xamarin.Forms since the writing of the book. These changes are:

• In code files, the deprecated Device.OnPlatform calls have been replaced with logic using the Device.RuntimePlatform property.
• In XAML files, deprecated properties of the OnPlatform class have been replaced with On objects.
• The use of the deprecated Device.TargetPlatform property have been replaced with Device.RuntimePlatform.
• Calls to the deprecated VisualElement.GetSizeRequest method have been replaced with calls to Measure.
• Overrides of the deprecated VisualElement.OnSizeRequest method have been replaced with overrides of OnMeasure.
• Calls to and implementations of the deprecated TypeConverter.ConvertFrom method have been replaced with ConvertFromInvariantString.
• The NamedColor class is now based on the Color structure rather than its own static fields.
• The Android projects have been upgraded to use AppCompat and Material Design. This is consistent with recent Xamarin.Forms project templates.
• The blank bitmaps in the Assets folder of the UWP projects have been replaced with Xamagon images.
• Event firing uses the null-conditional operator (?.) and the Invoke method.

The Projects

These solutions contain three application projects:

• iOS: iPhone and iPads
• Droid: Android phones and tablets
• UWP: The Universal Windows Platform, targeting Windows 10 tablets and desktop computers, and Windows 10 Mobile

The original-code-from-book branch also contains the following two applicatin projects:

• Windows: Windows 8.1 tablets and desktop computers using the Windows Runtime API
• WinPhone: Windows Phone 8.1 devices using the Windows Phone API.

You can deploy the UWP project to devices or emulators. However, you must select the correct platform for the deployment target. You generally do this by selecting a platform for the solution in the Solution Platform dropdown on the Standard toolbar. Or, you can invoke the Configuration Manager dialog form the Build | Configuration Manager menu item, and select an item from the Active solution platform dropdown at the top right.

The six possible Solution Platform options are listed below. Each is associated with a particular platform for the UWP project. This platform refers to processor architectures:

• Any CPU: UWP platform is x86
• ARM: UWP platform is ARM
• iPhone: UWP platform is x86
• iPhone Simulator: UWP platform is x86
• x86: UWP platform is x86
• x64: UWP platform is x64

These reflect the only three possibilities for the UWP project. As you can see, x86 (32-bit Intel architecture) is considered to be the default.

Currently, you can deploy the UWP project in several different ways based on a selection in the dropdown on the Standard toolbar.

• Select Local Machine to deploy directly to the Windows 10 desktop. The UWP platform must be x86 or x64.

• Select Simulator to deploy to a Windows 10 simulator window. The UWP platform must be x86.

• Select one of the items beginning with the words Mobile Emulator 10.0 to deploy to a Windows 10 Mobile emulator. The UWP platform must be x86.

• Select Device to deploy to a Windows 10 Mobile device. The UWP platform must be ARM.

Version upgrades

As of August 12, 2016, all sample code has been upgraded to Xamarin.Forms version 2.3.1.114.

As of November 23, 2016, all sample code has been upgraded to Xamarin.Forms version 2.3.3.168.

As of May 2, 2017, all sample code has been upgraded to Xamarin.Forms version 2.3.4.231.

As of November 3, 2017, all sample code has been upgraded to Xamarin.Forms version 2.4.0.38779.

As of April 13, 2018, all sample code has been upgraded to Xamarin.Forms version 2.5.0.280555.

Removing Obsolete Project Types

As of April 17, 2018, all Windows (Windows 8.1) and WinPhone (Windows Phone 8.1) projects have been removed from the samples. The Windows and WinPhone projects can still be found in the original-code-from-book branch.

.NET Standard

As of May 3, 2018, all solutions in the master branch have been converted from using Portable Class Libraries (PCL) to .NET Standard 2.0 libraries. In addition, the application projects have been converted to a new format using PackageReference. This conversion makes the solutions much closer to what Visual Studio 2017 creates today as a new Xamarin.Forms solution.

The new features of the .csproj files simplify the references to NuGet libraries. There are no longer any packages.config files in any of the projects, and the references to NuGet libraries in the .csproj files are greatly reduced in bulk. The .NET Standard Library project no longer has an AssemblyInfo.cs file, and the UWP project no longer has any project.json or project.lock.json files.

The solutions using PCL's have been archived in the archive-pcl branch. That branch will not be updated.

It is recommended that all new Xamarin.Forms projects be created with Visual Studio 2017, and that Visual Studio 2017 also be used for existing Xamarin.Forms projects.

As of May 4, 2018, all solutions in the master branch have been upgraded to Xamarin.Forms 2.5.1.527436.

As of May 9, 2018, all solutions in the master branch have been upgraded to Xamarin.Forms 3.0.0.446417.

As of July 17, 2018, all solutions in the master branch have been upgraded to Xamarin.Forms 3.1.0.637273.

As of September 4, 2018, all iOS projects in the master branch have been restricted to 64-bit architectures.

As of September 10, 2018, the deprecated AndroidUseLastestPlatformSdk element has been removed from all Android project files in the master branch.

As of September 14, 2018, another PropertyGroup has been added to the .NET Standard library with a DebugType element. This is required for setting breakpoints when deploying to the UWP.