Download Tutorial22.tarThis tutorial builds on tutorial 21. We take our JSON result array to build an ArrayList with our custom class, rather than a String. This allows us to do more useful things with the structured data our remote url returns to our application. We also bring back our ArrayAdapter and ViewHolder technique, with a slight modification to work with our new ArrayList.
Download Tutorial21.tarThis tutorial is our first tutorial that deals JSON handling in an Android application. We pull a json encoded array from a URL, and display it in our textview, using the JSONArray and JSONOBject Classes. This tutorial is very similar to 20, as we use the same basic series of classes to get our data from the internet.
Download Tutorial20.tarThis tutorial is our first tutorial that deals with accessing information over the internet. This tutorial creates an activity with a single textview, the uses a series of classes to make a request from a URL, and then display the contents of that URL in our TextView.
Download Tutorial19.tarThis tutorial is a re-implementation of number 13 using the AlertDialog. This is a list with the ability to insert, update, and delete entries. This tutorial illustrates how to save a list to a database. We use a custom adapter class, the holder technique, and a custom database helper class….and also the AlertDialog and DialogInterface 😉
Download Tutorial18.tarBy Request, this tutorial is a very simple variation on number 11. We create a simple list of notes, which we can add to using an AlertDialog and DialogInterface.
Download Tutorial17.tarThis tutorial shows you how to overwrite a database file with another database file using the onUpgrade method. This is NOT the prefered way to do this, as you will lose any data your application’s users have put in their database (DUH) BUT…If your application does not write to the database, you can get away with this.
Download Tutorial16.tarBy request, this is an extension on example 15. This tutorial shows how to create a list from a database, click on an item from that list, then pass the result of that click to another activity, AND THEN ANOTHER LIST in the new activity based on the passed variable.
This tutorial shows how to create a list from a database, click on an item from that list, then pass the result of that click to another activity. We do this using Intent Extras. This tutorial uses Tutorial 10 as its base. We add a second activity and an onItemClickListener to it.
This is a quick update to Tutorial 7. In this tutorial, we fully abstract our ViewHolder class. We implement a constructor and a populateFrom method, so that all future modifications can be done to the viewHolder class, without having to touch the Adapter. This is the basic ViewHolder that we will be using in all future tutorials, as needed, so it is a good idea to understand what it does.
In this video, we introduce the ViewHolder class, and why we like it. The ViewHolder class is used in conjunction with an ArrayAdapter, to cache the results of all findViewById calls. This speeds up our lists by up to 30 percent when we start dealing with very large lists.