Xamarin

Native apps for multiple platforms (iOS, Android and Windows) on a shared C# codebase.

• Xamarin.Forms: Apps that require little platform-specific functionality (Code sharing is more important than custom UI).
• Xamarin.iOS & Xamarin.Android: Apps with interactions that require native behavior (Custom UI is more important than code sharing).

Templates:

• Xamarin.Android: https://github.com/proyecto26/Xamarin/tree/master/src/android/App

  A Xamarin.Android example using mocks.

• Xamarin.Android & Xamarin.iOS https://github.com/proyecto26/Xamarin/tree/master/src/crossplatform/App

  A template with a lot of examples of each platform.

Structure

Each type of project has its own structure:

• Xamarin Forms Project Structure (Cross-platform)

Path	Explanation
./App.xaml	Global resources in the app.
./App.xaml.cs	Extend the app.

• Android Project Structure

Path	Explanation
./MainActivity.cs	Main Class.
./Resources/layout/Main.axml	Graphic Interface using XAML.
./Components	Add new features and third-party services.

• iOS Project Structure

Path	Explanation
./ViewController.cs	Main Class. We can configure alerts about Memory, Storage, etc.
./Main.storyboard	Create screens like default.
./LaunchScreen.storyboard	Boot screen.
./Info.plist	Permissions.
./AppDelegate.cs	Validate the status of the application to know when the application is active, running or finished.
./Components	Add new features and third-party services.

Sharing Code

There are some strategies for sharing code between platforms:

• Shared Asset Project (SAP): Files and source code that are combined at compile time.
• Portable Class Library (PCL): A DLL library that encapsulates common code and can be referenced from other projects.

Xamarin.Forms

A Xamaring Forms project summary.

XAML

The design of the views is usually developed in XAML:

<ContentPage xmlns="..." xmlns:x="..." x:Class="App.MainPage" Title="My App">
  <Label Text="Hello World!" VerticalOptions="Center" HorizontalOptions="Center" FontSize="Large">
    <OnPlatform x:TypeArguments="Text"
                iOS="Hello iOS World!"
                Android="Hello Android World!"
                WinPhone="Hello Windows World!" />
  </Label>
</ContentPage>

Also you can modify the views from classes:

if(Device.OS == TargetPlatform.iOS){
  label.Text = "Hello iOS World!";
}

Xamarin.Android

A Xamarin Android project summary.

Alternative resources

Qualifier	Description
MCC and MNC	Mobile Country Code and Mobile Network Code. Example: mcc310-mnc026 (EEUU/T-Mobile). Check the list of codes here.
Language	The language code and optionally the region code. Example: es-rCO (Spanish/Colombia with 'r' character as separator).
Smaller width	The smallest width supported by the app. Example: sw320dp (Height and width of at least 320dp).
Width available	The minimum screen width, this value may change as the device rotates. Example: w720dp (Width of at least 720dp).
Height available	The minimum screen height, this value may change as the device rotates. Example: h720dp (Width of at least 720dp).
Screen size	Size for which resources are allocated. Values: small/normal/large/xlarge.
Screen aspect	It is based on the aspect ratio. Values: long/notlong.
Screen orientation	Portrait (Vertical) and Landscape (Horizontal). Values: port/land.
Dock mode	For devices in a Car Dock or Desk Dock. Values: car/desk.
Night mode	Manage different versions for day and night. Values: night/notnight.
Display pixel density	The number of pixels in a physical area of the screen. Values: ldpi/mdpi/hdpi/xhdpi/nodpi/tvdpi.
Touch screen type	Specifies the type of touchscreen that a device can have. Values: notouch/stylus/finger (Non-touch screens, optical pencil or touch screens).
Keyboard availability	The type of keyboard available. Values: keysexposed/keyshidden/keyssoft (Keyboard available, hardware keyboard or software keyboard).
Main text input method	Types of hardware keys available. Values: nokeys/qwerty/12key (No hardware keys, qwerty keyboard available or 12-key keyboard hardware).
Navigation key availability	When 5-way or d-pad navigation is available. Values: navexposed/navhidden (Available or unavailable).
Main non-touch navigation method	Type of navigation available on the device. Values: nonav/dpad/trackball/wheel (Touch screen only, d-pad available, Trackball available or wheels available).
Platform version (API Level)	The API level supported. Example: v11 (Level 11 - Android 3.0).

Create controls dynamically

//Find the layout
var viewGroup = Window.DecorView.FindViewById<ViewGroup>(Android.Resource.Id.Content);
var mainLayout = viewGroup.FindViewById<LinearLayout>(Resource.Id.main_content);

//Create an image
var headerImage = new ImageView(this);
headerImage.SetImageResource(Resource.Drawable.logo);
mainLayout.AddView(headerImage);

//Create a text area
var userNameTextView = new TextView(this);
userNameTextView.Text = GetString(Resource.String.UserName);
mainLayout.AddView(userNameTextView);

Xamarin.iOS

A Xamarin iOS project summary.

Tips

Check the support of the APIs at runtime - Xamarin.Android

We can detect the current version of Android to validate the APIs that we can use and support old Android platforms (Android fragmentation):

if(Android.OS.Build.VERSION.SdkInt >= BuildVersionCodes.Lollipop){
  var builder = new Notification.Builder(this);
  builder.SetCategory(Notification.CategoryMessage);
}
else{
  new AlertDialog.Builder(this).SetMessage("Your Android version doesn't support...")
}

Conditional Compilation for shared resources

We can identify some compilation symbols for shared projects:

• MOBILE (Android and iOS platforms)
• IOS (Xamarin.iOS)
• ANDROID (Xamarin.Android)
• WINDOWS_UWP (Windows)

#if __ANDROID__
    string libraryPath = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
#elif __IOS__
    string documentsPath = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
    string libraryPath = Path.Combine(documentsPath, "..", "Library");
#else
    string libraryPath = Windows.Storage.ApplicationData.Current.LocalFolder.Path;
#endif
var path = Path.Combine(libraryPath, fileName);

Note: You can specify platform versions, for example: __ANDROID_22__. Also you can create your own conditional compilation symbols from Project Properties/Build section.

Remote Login for Mac

• Enable Remote Login option on Mac:

  System Preferences => Sharing => Remote Login (Configure access)

• Connect to Mac:

  Visual Studio => Tools => Options => Xamarin => iOS Settings => Find Xamarin Mac Agent

Note: A SSH key will be created and registered in the file authorized_keys on the Mac.

Other projects

• Hack@Home - Xamarin 3.0.

Credits 👍

• TI Capacitación

Contributing ✨

When contributing to this repository, please first discuss the change you wish to make via issue, email, or any other method with the owners of this repository before making a change.
Contributions are what make the open-source community such an amazing place to learn, inspire, and create. Any contributions you make are greatly appreciated ❤️.
You can learn more about how you can contribute to this project in the contribution guide.

Supporting 🍻

I believe in Unicorns 🦄 Support me, if you do too.

Donate Ethereum, ADA, BNB, SHIBA, USDT/USDC, DOGE, etc:

Wallet address: jdnichollsc.eth

Please let us know your contributions! 🙏

License ⚖️

This repository is available under the MIT License.

Happy coding 💯

Made with <3