Book Image

Xamarin 4.x Cross-Platform Application Development - Third Edition

By : Jonathan Peppers
Book Image

Xamarin 4.x Cross-Platform Application Development - Third Edition

By: Jonathan Peppers

Overview of this book

Xamarin is a leading cross-platform application development tool used by top companies such as Coca-Cola, Honeywell, and Alaska Airlines to build apps. Version 4 features significant updates to the platform including the release of Xamarin.Forms 2.0 and improvements have been made to the iOS and Android designers. Xamarin was acquired by Microsoft so it is now a part of the Visual Studio family. This book will show you how to build applications for iOS, Android, and Windows. You will be walked through the process of creating an application that comes complete with a back-end web service and native features such as GPS location, camera, push notifications, and other core features. Additionally, you’ll learn how to use external libraries with Xamarin and Xamarin.Forms to create user interfaces. This book also provides instructions for Visual Studio and Windows. This edition has been updated with new screenshots and detailed steps to provide you with a holistic overview of the new features in Xamarin 4.
Table of Contents (19 chapters)
Xamarin 4.x Cross-Platform Application Development - Third Edition
About the Author
About the Reviewer
Customer Feedback

Composing messages

For the final piece of our application, we need to implement some custom functionality that Apple doesn't provide with their APIs. We need to add a text field with a button that appears to be attached to the bottom of the table view. Most of this will require writing some simple C# code and wiring up events.

Let's begin by adding some new member variables to our MessagesController class, as follows:

UIToolbar toolbar; 
UITextField message; 
UIBarButtonItem send; 

We will place the text field and bar buttons inside the toolbar, as in the following code in ViewDidLoad:

public override void ViewDidLoad() 
  //Text Field 
  message = new UITextField( 
    new CGRect(0, 0, TableView.Frame.Width - 88, 32)) 
    BorderStyle = UITextBorderStyle.RoundedRect, 
    ReturnKeyType = UIReturnKeyType.Send, 
    ShouldReturn = _ => 
        return false...