Mobile Development with C#

Chapter 5. Storing Data

Whether it is saving a user’s input or caching data pulled down from a web service, every application needs some way to persist its data for retrieval. There are various options available for storing data in your applications. This chapter will explore two of the primary methods for doing so: reading and writing files to the filesystem and making use of the device’s local database. Each platform provides different capabilities for both the filesystem and databases, but thanks to the shared usage of the .NET framework, there is still plenty of potential for code reuse across each of them.

In this chapter, we will be building a simple note-taking application where the user can save notes, each consisting of a title and body text. The user will also be able to view a list of his saved notes and have the option of viewing or deleting them. Before implementing the actual data persistence, we will first build the sample application, demonstrating how to leverage the abstraction pattern to allow the application to be ignorant of those implementations.

Following that, we will add an implementation to save the data to the local filesystem. In addition to that implementation, we will look at the differences in filesystem access across platforms, and what you can do on each of them. Finally, we will extend the application to use a local database to perform the same task, again discussing the important platform capabilities and differences to be aware of. While building ...