Search icon CANCEL
Arrow left icon
Explore Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Conferences
Free Learning
Arrow right icon
Mastering Xamarin.Forms
Mastering Xamarin.Forms

Mastering Xamarin.Forms: Build rich, maintainable, multi-platform, native mobile apps with Xamarin.Forms , Second Edition

eBook
€13.98 €19.99
Paperback
€24.99
Subscription
Free Trial
Renews at €18.99p/m

What do you get with Print?

Product feature icon Instant access to your digital eBook copy whilst your Print order is Shipped
Product feature icon Paperback book shipped to your preferred address
Product feature icon Download this book in EPUB and PDF formats
Product feature icon Access this title in our online reader with advanced features
Product feature icon DRM FREE - Read whenever, wherever and however you want
Table of content icon View table of contents Preview book icon Preview Book

Mastering Xamarin.Forms

MVVM and Data Binding

In this chapter, we will take a look at the Model-View-ViewModel (MVVM) pattern, the MVVM elements that are offered with the Xamarin.Forms toolkit, and how we can expand on them to truly take advantage of the power of the pattern. As we dig into these topics, we will apply what we have learned to the TripLog app that we started building in Chapter 1, Getting Started.

In this chapter, we will cover the following topics:

  • Understanding the MVVM pattern and data binding
  • MVVM in the Xamarin.Forms toolkit
  • Adding the MVVM pattern and data binding to the Xamarin.Forms mobile app created in Chapter 1, Getting Started

Understanding the MVVM pattern

At its core, MVVM is a presentation pattern designed to control the separation between user interfaces and the rest of an application. The key elements of the MVVM pattern are as follows:

  • Models: Models represent the business entities of an application. When responses come back from an API, they are typically deserialized to models.
  • Views: Views represent the actual pages or screens of an application, along with all of the elements that make them up, including custom controls. Views are very platform-specific and depend heavily on platform APIs to render the application's user interface (UI).
  • ViewModels: ViewModels control and manipulate the Views by serving as their data context. ViewModels are made up of a series of properties represented by Models. These properties are part of what is bound to the Views to provide the data that is displayed...

Adding MVVM to the app

The first step of introducing MVVM into an app is to set up the structure by adding folders that will represent the core tenants of the pattern, such as Models, ViewModels, and Views. Traditionally, the Models and ViewModels live in a core library (usually, a portable class library or .NET standard library), whereas the Views live in a platform-specific library. Thanks to the power of the Xamarin.Forms toolkit and its abstraction of platform-specific UI APIs, the Views in a Xamarin.Forms app can also live in the core library.

Just because the Views can live in the core library with the ViewModels and Models, this doesn't mean that separation between the user interface and the app logic isn't important.

When implementing a specific structure to support a design pattern, it is helpful to have your application namespaces organized in a similar structure...

Summary

In this chapter, we updated the app that we started creating in Chapter 1, Getting Started, by removing data and data-related logic from the Pages, offloading it to a series of ViewModels, and then binding the Pages to those ViewModels. In the next chapter, we will expand on the Xamarin.Forms navigation service so that we can also move navigation code from the Pages to the ViewModels.

Left arrow icon Right arrow icon

Key benefits

  • Packed with real-world scenarios and solutions to help you build professional grade mobile apps with Xamarin.Forms
  • Build an effective mobile app architecture with the Xamarin.Forms toolkit
  • Maximize the overall quality of your Xamarin.Forms apps

Description

Discover how to extend and build upon the components of the Xamarin.Forms toolkit to develop effective, robust mobile app architecture. Starting with an app built with the basics of the Xamarin.Forms toolkit, we'll go step by step through several advanced topics to create a solution architecture rich with the benefits of good design patterns and best practices. We'll start by introducing a core separation between the app's user interface and the app's business logic by applying the MVVM pattern and data-binding. Then we will focus on building out a layer of plugin-like services that handle platform-specific utilities such as navigation and geo-location, as well as how to loosely use these services in the app with inversion of control and dependency injection. Next we'll connect the app to a live web-based API and set up offline synchronization. Then, we'll dive into testing the app logic through unit tests. Finally, we will setup Visual Studio App Center to automate building, testing, distributing and monitoring the app.

Who is this book for?

This book is intended for C# developers who are familiar with the Xamarin platform and the Xamarin.Forms toolkit. If you have already started working with Xamarin.Forms and want to take your app to the next level with higher quality, maintainability, testability, and flexibility, then this book is for you.

What you will learn

  • Find out how, when, and why you should use architecture patterns and get best practices with Xamarin.Forms
  • Implement the Model-View-ViewModel (MVVM) pattern and data-binding in Xamarin.Forms mobile apps
  • Extend the Xamarin.Forms navigation API with a custom ViewModel-centric navigation service
  • Leverage the inversion of control and dependency injection patterns in Xamarin.Forms mobile apps
  • Work with online and offline data in Xamarin.Forms mobile apps
  • Test business logic in Xamarin.Forms mobile apps
  • Use platform-specific APIs to build rich custom user interfaces in Xamarin.Forms mobile apps
  • Explore how to improve mobile app quality using Visual Studio App Center
Estimated delivery fee Deliver to Cyprus

Premium delivery 7 - 10 business days

€32.95
(Includes tracking information)

Product Details

Country selected
Publication date, Length, Edition, Language, ISBN-13
Publication date : Mar 27, 2018
Length: 192 pages
Edition : 2nd
Language : English
ISBN-13 : 9781788290265
Vendor :
Microsoft
Category :
Languages :
Tools :

What do you get with Print?

Product feature icon Instant access to your digital eBook copy whilst your Print order is Shipped
Product feature icon Paperback book shipped to your preferred address
Product feature icon Download this book in EPUB and PDF formats
Product feature icon Access this title in our online reader with advanced features
Product feature icon DRM FREE - Read whenever, wherever and however you want
Estimated delivery fee Deliver to Cyprus

Premium delivery 7 - 10 business days

€32.95
(Includes tracking information)

Product Details

Publication date : Mar 27, 2018
Length: 192 pages
Edition : 2nd
Language : English
ISBN-13 : 9781788290265
Vendor :
Microsoft
Category :
Languages :
Tools :

Packt Subscriptions

See our plans and pricing
Modal Close icon
€18.99 billed monthly
Feature tick icon Unlimited access to Packt's library of 7,000+ practical books and videos
Feature tick icon Constantly refreshed with 50+ new titles a month
Feature tick icon Exclusive Early access to books as they're written
Feature tick icon Solve problems while you work with advanced search and reference features
Feature tick icon Offline reading on the mobile app
Feature tick icon Simple pricing, no contract
€189.99 billed annually
Feature tick icon Unlimited access to Packt's library of 7,000+ practical books and videos
Feature tick icon Constantly refreshed with 50+ new titles a month
Feature tick icon Exclusive Early access to books as they're written
Feature tick icon Solve problems while you work with advanced search and reference features
Feature tick icon Offline reading on the mobile app
Feature tick icon Choose a DRM-free eBook or Video every month to keep
Feature tick icon PLUS own as many other DRM-free eBooks or Videos as you like for just €5 each
Feature tick icon Exclusive print discounts
€264.99 billed in 18 months
Feature tick icon Unlimited access to Packt's library of 7,000+ practical books and videos
Feature tick icon Constantly refreshed with 50+ new titles a month
Feature tick icon Exclusive Early access to books as they're written
Feature tick icon Solve problems while you work with advanced search and reference features
Feature tick icon Offline reading on the mobile app
Feature tick icon Choose a DRM-free eBook or Video every month to keep
Feature tick icon PLUS own as many other DRM-free eBooks or Videos as you like for just €5 each
Feature tick icon Exclusive print discounts

Frequently bought together


Stars icon
Total 94.97
Mastering Xamarin UI Development
€36.99
Mastering Xamarin.Forms
€24.99
Xamarin.Forms Projects
€32.99
Total 94.97 Stars icon

Table of Contents

10 Chapters
Getting Started Chevron down icon Chevron up icon
MVVM and Data Binding Chevron down icon Chevron up icon
Navigation Chevron down icon Chevron up icon
Platform Specific Services and Dependency Injection Chevron down icon Chevron up icon
User Interface Chevron down icon Chevron up icon
API Data Access Chevron down icon Chevron up icon
Authentication Chevron down icon Chevron up icon
Testing Chevron down icon Chevron up icon
App Monitoring Chevron down icon Chevron up icon
Other Books You May Enjoy Chevron down icon Chevron up icon

Customer reviews

Top Reviews
Rating distribution
Full star icon Full star icon Full star icon Full star icon Half star icon 4.4
(15 Ratings)
5 star 66.7%
4 star 6.7%
3 star 26.7%
2 star 0%
1 star 0%
Filter icon Filter
Top Reviews

Filter reviews by




Amazon Customer Apr 11, 2018
Full star icon Full star icon Full star icon Full star icon Full star icon 5
This book is an essential resource for anyone building cross platform apps with Xamarin.Forms. It is practical, straightfoward and well written and replete with good examples.
Amazon Verified review Amazon
Richard Taylor Jun 19, 2018
Full star icon Full star icon Full star icon Full star icon Full star icon 5
Great information and read on Xamarin.Forms!
Amazon Verified review Amazon
Amazon Customer Apr 18, 2018
Full star icon Full star icon Full star icon Full star icon Full star icon 5
This is an excellent book. The author presents the information in a clear and concise manner. As a novice in Xamarin I was able to gain a great deal of understanding of Xamarin Forms.
Amazon Verified review Amazon
Amazon-klant May 23, 2018
Full star icon Full star icon Full star icon Full star icon Full star icon 5
Good, succinct and quite to the point, clearly written and well explained code samples complete the explanations. A good introduction
Amazon Verified review Amazon
Amz Buyer Oct 08, 2019
Full star icon Full star icon Full star icon Full star icon Full star icon 5
For beginners who are starting up with Xamarin, this is a good book. This helped me kick start.
Amazon Verified review Amazon
Get free access to Packt library with over 7500+ books and video courses for 7 days!
Start Free Trial

FAQs

What is the delivery time and cost of print book? Chevron down icon Chevron up icon

Shipping Details

USA:

'

Economy: Delivery to most addresses in the US within 10-15 business days

Premium: Trackable Delivery to most addresses in the US within 3-8 business days

UK:

Economy: Delivery to most addresses in the U.K. within 7-9 business days.
Shipments are not trackable

Premium: Trackable delivery to most addresses in the U.K. within 3-4 business days!
Add one extra business day for deliveries to Northern Ireland and Scottish Highlands and islands

EU:

Premium: Trackable delivery to most EU destinations within 4-9 business days.

Australia:

Economy: Can deliver to P. O. Boxes and private residences.
Trackable service with delivery to addresses in Australia only.
Delivery time ranges from 7-9 business days for VIC and 8-10 business days for Interstate metro
Delivery time is up to 15 business days for remote areas of WA, NT & QLD.

Premium: Delivery to addresses in Australia only
Trackable delivery to most P. O. Boxes and private residences in Australia within 4-5 days based on the distance to a destination following dispatch.

India:

Premium: Delivery to most Indian addresses within 5-6 business days

Rest of the World:

Premium: Countries in the American continent: Trackable delivery to most countries within 4-7 business days

Asia:

Premium: Delivery to most Asian addresses within 5-9 business days

Disclaimer:
All orders received before 5 PM U.K time would start printing from the next business day. So the estimated delivery times start from the next day as well. Orders received after 5 PM U.K time (in our internal systems) on a business day or anytime on the weekend will begin printing the second to next business day. For example, an order placed at 11 AM today will begin printing tomorrow, whereas an order placed at 9 PM tonight will begin printing the day after tomorrow.


Unfortunately, due to several restrictions, we are unable to ship to the following countries:

  1. Afghanistan
  2. American Samoa
  3. Belarus
  4. Brunei Darussalam
  5. Central African Republic
  6. The Democratic Republic of Congo
  7. Eritrea
  8. Guinea-bissau
  9. Iran
  10. Lebanon
  11. Libiya Arab Jamahriya
  12. Somalia
  13. Sudan
  14. Russian Federation
  15. Syrian Arab Republic
  16. Ukraine
  17. Venezuela
What is custom duty/charge? Chevron down icon Chevron up icon

Customs duty are charges levied on goods when they cross international borders. It is a tax that is imposed on imported goods. These duties are charged by special authorities and bodies created by local governments and are meant to protect local industries, economies, and businesses.

Do I have to pay customs charges for the print book order? Chevron down icon Chevron up icon

The orders shipped to the countries that are listed under EU27 will not bear custom charges. They are paid by Packt as part of the order.

List of EU27 countries: www.gov.uk/eu-eea:

A custom duty or localized taxes may be applicable on the shipment and would be charged by the recipient country outside of the EU27 which should be paid by the customer and these duties are not included in the shipping charges been charged on the order.

How do I know my custom duty charges? Chevron down icon Chevron up icon

The amount of duty payable varies greatly depending on the imported goods, the country of origin and several other factors like the total invoice amount or dimensions like weight, and other such criteria applicable in your country.

For example:

  • If you live in Mexico, and the declared value of your ordered items is over $ 50, for you to receive a package, you will have to pay additional import tax of 19% which will be $ 9.50 to the courier service.
  • Whereas if you live in Turkey, and the declared value of your ordered items is over € 22, for you to receive a package, you will have to pay additional import tax of 18% which will be € 3.96 to the courier service.
How can I cancel my order? Chevron down icon Chevron up icon

Cancellation Policy for Published Printed Books:

You can cancel any order within 1 hour of placing the order. Simply contact customercare@packt.com with your order details or payment transaction id. If your order has already started the shipment process, we will do our best to stop it. However, if it is already on the way to you then when you receive it, you can contact us at customercare@packt.com using the returns and refund process.

Please understand that Packt Publishing cannot provide refunds or cancel any order except for the cases described in our Return Policy (i.e. Packt Publishing agrees to replace your printed book because it arrives damaged or material defect in book), Packt Publishing will not accept returns.

What is your returns and refunds policy? Chevron down icon Chevron up icon

Return Policy:

We want you to be happy with your purchase from Packtpub.com. We will not hassle you with returning print books to us. If the print book you receive from us is incorrect, damaged, doesn't work or is unacceptably late, please contact Customer Relations Team on customercare@packt.com with the order number and issue details as explained below:

  1. If you ordered (eBook, Video or Print Book) incorrectly or accidentally, please contact Customer Relations Team on customercare@packt.com within one hour of placing the order and we will replace/refund you the item cost.
  2. Sadly, if your eBook or Video file is faulty or a fault occurs during the eBook or Video being made available to you, i.e. during download then you should contact Customer Relations Team within 14 days of purchase on customercare@packt.com who will be able to resolve this issue for you.
  3. You will have a choice of replacement or refund of the problem items.(damaged, defective or incorrect)
  4. Once Customer Care Team confirms that you will be refunded, you should receive the refund within 10 to 12 working days.
  5. If you are only requesting a refund of one book from a multiple order, then we will refund you the appropriate single item.
  6. Where the items were shipped under a free shipping offer, there will be no shipping costs to refund.

On the off chance your printed book arrives damaged, with book material defect, contact our Customer Relation Team on customercare@packt.com within 14 days of receipt of the book with appropriate evidence of damage and we will work with you to secure a replacement copy, if necessary. Please note that each printed book you order from us is individually made by Packt's professional book-printing partner which is on a print-on-demand basis.

What tax is charged? Chevron down icon Chevron up icon

Currently, no tax is charged on the purchase of any print book (subject to change based on the laws and regulations). A localized VAT fee is charged only to our European and UK customers on eBooks, Video and subscriptions that they buy. GST is charged to Indian customers for eBooks and video purchases.

What payment methods can I use? Chevron down icon Chevron up icon

You can pay with the following card types:

  1. Visa Debit
  2. Visa Credit
  3. MasterCard
  4. PayPal
What is the delivery time and cost of print books? Chevron down icon Chevron up icon

Shipping Details

USA:

'

Economy: Delivery to most addresses in the US within 10-15 business days

Premium: Trackable Delivery to most addresses in the US within 3-8 business days

UK:

Economy: Delivery to most addresses in the U.K. within 7-9 business days.
Shipments are not trackable

Premium: Trackable delivery to most addresses in the U.K. within 3-4 business days!
Add one extra business day for deliveries to Northern Ireland and Scottish Highlands and islands

EU:

Premium: Trackable delivery to most EU destinations within 4-9 business days.

Australia:

Economy: Can deliver to P. O. Boxes and private residences.
Trackable service with delivery to addresses in Australia only.
Delivery time ranges from 7-9 business days for VIC and 8-10 business days for Interstate metro
Delivery time is up to 15 business days for remote areas of WA, NT & QLD.

Premium: Delivery to addresses in Australia only
Trackable delivery to most P. O. Boxes and private residences in Australia within 4-5 days based on the distance to a destination following dispatch.

India:

Premium: Delivery to most Indian addresses within 5-6 business days

Rest of the World:

Premium: Countries in the American continent: Trackable delivery to most countries within 4-7 business days

Asia:

Premium: Delivery to most Asian addresses within 5-9 business days

Disclaimer:
All orders received before 5 PM U.K time would start printing from the next business day. So the estimated delivery times start from the next day as well. Orders received after 5 PM U.K time (in our internal systems) on a business day or anytime on the weekend will begin printing the second to next business day. For example, an order placed at 11 AM today will begin printing tomorrow, whereas an order placed at 9 PM tonight will begin printing the day after tomorrow.


Unfortunately, due to several restrictions, we are unable to ship to the following countries:

  1. Afghanistan
  2. American Samoa
  3. Belarus
  4. Brunei Darussalam
  5. Central African Republic
  6. The Democratic Republic of Congo
  7. Eritrea
  8. Guinea-bissau
  9. Iran
  10. Lebanon
  11. Libiya Arab Jamahriya
  12. Somalia
  13. Sudan
  14. Russian Federation
  15. Syrian Arab Republic
  16. Ukraine
  17. Venezuela