Xamarin.Forms is renowned for its ability to create cross-platform applications that run seamlessly on multiple platforms. However, when it comes to managing application preferences, developers often face challenges due to the varying file systems and storage mechanisms used by each platform. In this article, we'll explore how Xamarin.Essentials can simplify the process of storing and retrieving application preferences using a key-value store.

Xamarin.Essentials is a powerful plugin that provides 20+ cross-platform APIs for mobile app development. With Xamarin.Essentials, developers can access native platform APIs using C#, eliminating the need for multiple plugins or workarounds. By leveraging Xamarin.Essentials, you can create robust and efficient applications that cater to diverse user preferences.

Platform Support

Xamarin.Essentials supports a wide range of platforms and operating systems, including:

  • Android: 4.4 (API 19) or earlier
  • iOS: 10.0 or higher
  • UWP: 10.0.16299.0 or earlier

Application Storage

When it comes to storing application preferences, each platform has its unique approach. On Android, developers can utilize the Shared Preferences mechanism, which allows for saving and retrieving data in a key-value pair format. On iOS, the NSUserDefaults class provides a way for apps and extensions to interact with the system-wide Default System, enabling users to configure app behavior or styling based on their preferences.

In contrast, UWP applications can rely on the ApplicationDataContainer class, which represents a container for app settings. This allows developers to create, delete, enumerate, and traverse the container hierarchy.

Xamarin.Forms applications, on the other hand, can utilize the Properties dictionary, which is accessible from anywhere in the code using Application.Current.Properties.

Preferences Class

The Preferences class in Xamarin.Essentials provides a key-value store for storing application preferences. This class supports a range of data types, including:

  • String
  • Int
  • Bool
  • Double
  • Float
  • Long
  • DateTime

With Xamarin.Essentials, developers can easily store and retrieve application preferences using a simple API.

Getting Started

To get started with Xamarin.Essentials, follow these steps:

  1. Create a new Xamarin.Forms project in Visual Studio 2017 (Windows or Mac).
  2. Choose the Xamarin.Forms App Project type under Cross-platform/App.
  3. Name your app and select "Use Portable Class Library" for shared code.
  4. Target both Android and iOS.

Setting Up the User Interface

To set up the user interface, open MainPage.xaml and add the following code:

`xml

xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"

xmlns:local="clr-namespace:XamarinEssentials"

x:Class="XamarinEssentials.MainPage">

`

Adding Xamarin Essentials

To add Xamarin.Essentials to your project, follow these steps:

  1. Go to Solution Explorer and select your solution.
  2. Right-click and select "Manage NuGet Packages for Solution".
  3. Search for "Xamarin.Essentials" and install the package.

Remember to install it for each project (PCL, Android, iOS, and UWP).

Platform-Specific Setup

For Android, you'll need to perform additional setup:

  1. Target Android version for compiling must be 8.1, API level 27.
  2. Initialize Xamarin.Essentials in the OnCreate method of your MainActivity:

`csharp

Xamarin.Essentials.Platform.Init(this, bundle);

`

  1. Handle runtime permissions by writing the following code:

`csharp

public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Android.Content.PM.Permission[] grantResults)

{

Xamarin.Essentials.Platform.OnRequestPermissionsResult(requestCode, permissions, grantResults);

base.OnRequestPermissionsResult(requestCode, permissions, grantResults);

}

`

No additional setup is required for iOS or UWP platforms.

By leveraging Xamarin.Essentials, you can create robust and efficient applications that cater to diverse user preferences. With its powerful APIs and seamless integration with Xamarin.Forms, you'll be able to develop cross-platform apps that meet the needs of your users.