Book Image

Xamarin Mobile Development for Android Cookbook

By : Matthew Leibowitz
Book Image

Xamarin Mobile Development for Android Cookbook

By: Matthew Leibowitz

Overview of this book

Xamarin is used by developers to write native iOS, Android, and Windows apps with native user interfaces and share code across multiple platforms not just on mobile devices, but on Windows, Mac OS X, and Linux. Developing apps with Xamarin.Android allows you to use and re-use your code and your skills on different platforms, making you more productive in any development. Although it’s not a write-once-run-anywhere framework, Xamarin provides native platform integration and optimizations. There is no middleware; Xamarin.Android talks directly to the system, taking your C# and F# code directly to the low levels. This book will provide you with the necessary knowledge and skills to be part of the mobile development era using C#. Covering a wide range of recipes such as creating a simple application and using device features effectively, it will be your companion to the complete application development cycle. Starting with installing the necessary tools, you will be guided on everything you need to develop an application ready to be deployed. You will learn the best practices for interacting with the device hardware, such as GPS, NFC, and Bluetooth. Furthermore, you will be able to manage multimedia resources such as photos and videos captured with the device camera, and so much more! By the end of this book, you will be able to create Android apps as a result of learning and implementing pro-level practices, techniques, and solutions. This book will ascertain a seamless and successful app building experience.
Table of Contents (20 chapters)
Xamarin Mobile Development for Android Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Selection alerts


Sometimes we have to ask the user to select one or more items from a larger collection. This may be necessary as normal dialogs only have up to three buttons, but a fully customized UI is unnecessary.

How to do it...

To provide a list of items in a dialog, we can specify the items in much the same way as a simple message:

  1. If we need to provide the user with a selection of items in a dialog, we can also use the AlertDialog instance and the SetItems() method:

    string[] items = new string[] { ... }
    using (var dialog = new AlertDialog.Builder(this)) {
      dialog.SetTitle("Alert Title");
      dialog.SetPositiveButton("Close", delegate { 
      });
      dialog.SetItems(items, (s, e) => {
        int index = e.Which;
      });
      dialog.Show();
    } 
  2. We can also use data adapters in a dialog, through the SetAdapter() method:

    var adapter = new ArrayAdapter(
      this, Android.Resource.Layout.SimpleListItem1, items);
    dialog.SetAdapter(adapter, (s, e) => {
      var index = e.Which;
    });
  3. If we want to support a single...