Migrate to Xamarin.IOS Unified API

Question

Recently i got a project which was build on Xamarin on Mac.Now, when i try to open this project on visual studio for MAC (As you all know Xamarin is now visual studio for MAC) it shows some errors regarding Monotouch.

The question is : Do i really need to convert app to unified API ? i know there is tutorial on official Xamarin doc to change app to unified API, but if there is any other way to open app without migrating to unified api.And what will be advantages and disadvantages of migration?

Answer 1

There are quite a few reasons why you might consider updating, but I will highlight some of the more important ones. Firstly consider that Apple as a manufacturer of hardware and software have always striven to keep their devices upto date, as such lagging behind as an iOS app developer can absolutely effect the demand for your app.

Firstly it already became a push or jump situation, as Xamarin stopped updating or supporting feature additions to their 'classic api' (As of writing we are on iOS 10.3).

The complete removal of classic support is scheduled for next fall with the release of Xamarin.iOS 10.0.

Secondly the unified API is required to meet apples desire to support 64bit architecture:

The new Unified APIs are required to support 64 bit device architectures from a Xamarin.iOS mobile application. As of February 1st, 2015 Apple requires that all new app submissions to the iTunes App Store support 64 bit architectures.

As to your concern regarding the dissadvantages, I will simply say that the migration can either go smoothly, or not so smoothly. It's worth bearing in mind that the 'unified api' uses different native data types which may require some work arounds depending on the current structure of your original code.

The biggest point is what I mentioned earlier, in Apples App Store if you linger behind in terms of keeping your app up to date with the latest SDK, API, or anything else Apple decide to upgrade, then it is akin to giving up on that application.

I've put together some links below that may aid you in the migration process:

Native Types - Describes the new native data types that you will need to use in a Unified API app.

32/64 bit Platform Considerations - Considerations in choosing 32-bit and 64-bit modes for your application.

Updating Existing iOS Apps - Follow these steps to update an existing Xamarin.iOS app to use the Unified API.

Binding Objective-C Libraries - This document describes the process used to create C# bindings of Objective-C APIs and how the idioms in Objective-C are mapped to the idioms used in .NET.If you are binding just C APIs, you should use the standard .NET mechanism for this, the P/Invoke framework.

Binding Definition Reference Guide - This is the reference guide that describes all of the attributes available to binding authors to drive the binding generation process.

Updating UI Components - This is a guide to the process for updating UI componenets to the latest versions within the unified api.