Showing posts with label ArrayAdapter. Show all posts
Showing posts with label ArrayAdapter. Show all posts

Sunday, November 25, 2012

ListView with Objects

Let's say you have just parsed some JSON data and you want to display them to a ListView.
For Simplicity sake I will assign all the properties of each item to only one TextView so we won't need to create a custom ArrayAdapter.

Assume that's our JSON data :

[  {"id":"1","title":"Homeland"},{"id":"2","title":"Breaking Bad"}{"id":"3","title":"Dexter"},{"id":"4","title":"Californication"}  ]

There's a JSON Array and that's everything in between [, ] and there are four  JSON Objects all of them with id and title properties.

First of all we are gonna create a class for our Objects :

public class TvShow() {
int id;
String title;
     public TvShow( int id, String title) { = id;
    this.title = title;
     public int getID() {
    return id;
        public String getTitle() {
    return title;
    public String toString(){
String toReturn = "ID = "+id + " Title= " +title ;
    return  toReturn;
Note that we need to Override the toString method for the Object TvShow so that every TextView in the list will display strings.

Initialize an ArrayList of  <TvShow> Obejcts :

     ArrayList<TvShow> alist = new ArrayList<TvShow>();

 So finally we store our data to a JSONArray object :

   JSONArray jArray = new JSONArray(result); //result is the String response we got from our web service

and get the length of the array. int len = jArray.length();

All we need to do now is a for statement to run the array for each item.

   for (int i = 0; i < len; i++) {
JSONObject jObj = jArray.getJSONObject(i);
            int _id = jObj.getInt("id");
String _title = jObj.getString("title");
                            JSONData jData = new JSONData(_id, _title);
   } catch (Exception e) {
// TODO: handle exception
return alist;

Now we have our ArrayList alist with TvShow Object's data.

            ArrayList<TvShow> results = GetResults(); //assuming the GetResults returns the alist from above

In our XML file we create a ListView and grab its id to the ListView item :

        ListView lv= (ListView)findViewById( );

Next we need to define our Adapter :
            ArrayAdapter<TvShow> arrayAdapter = new ArrayAdapter<TvShow>(this, android.R.layout.simple_list_item_1 , results );
The constructor is : 

public ArrayAdapter (Context context, int textViewResourceId, T[] objects)

The last thing we need to do is to assign the adapter to the ListView :

Now our ListView assings to an Object for every TextView item in the list.