Android中的搜索按钮功能

Question

My Android App is based on Job portal, i have parsed the info from website and got into listview, now the listview contains all categories of jobs, In the First activity there is a textbox and search button, what ever keyword for "Title" is given in the textbox only those categories of jobs should be displayed in the listview. To do this should i have to compare the elements in the "textbox" with website data or already parsed info in listview? for comparing the string in "textbox" and storing it separate array, where should i place the code, can anybody help?

public class Home extends ListActivity
{// url to make request
private static String url = "http://www.example.com/jobs/?json=get_recent_posts";

// JSON Node names
private static final String TAG_POSTS = "posts";
private static final String TAG_ID = "id";
private static final String TAG_TITLE = "title";
private static final String TAG_DATE = "date";
private static final String TAG_CONTENT = "content";
private static final String TAG_AUTHOR = "author";
private static final String TAG_NAME = "name";



// contacts JSONArray
JSONArray posts = null;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    // Hashmap for ListView
    ArrayList<HashMap<String, String>> contactList = new ArrayList<HashMap<String, String>>();

    // Creating JSON Parser instance
    JSONParser jParser = new JSONParser();

    // getting JSON string from URL
    JSONObject json = jParser.getJSONFromUrl(url);

    try {
        // Getting Array of Contacts
        posts = json.getJSONArray(TAG_POSTS);

        // looping through All Contacts
        for(int i = 0; i < posts.length(); i++){
            JSONObject c = posts.getJSONObject(i);

            // Storing each json item in variable
            String id = c.getString(TAG_ID);
            String title = c.getString(TAG_TITLE);
            String date = c.getString(TAG_DATE);
            String content = c.getString(TAG_CONTENT);

            content = content.replace("<br />", "");
            content = content.replace("<p>", "");
            content = content.replace("</p>", "");


            // Phone number is agin  JSON Object
            JSONObject author = c.getJSONObject(TAG_AUTHOR);
            String name = author.getString(TAG_NAME);


            // creating new HashMap
            HashMap<String, String> map = new HashMap<String, String>();

            // adding each child node to HashMap key => value
            map.put(TAG_ID, id);
            map.put(TAG_TITLE, title);
            map.put( TAG_DATE, date);
            map.put( TAG_NAME, name);
            map.put( TAG_CONTENT, content);
            // adding HashList to ArrayList
            contactList.add(map);
        }
    } catch (JSONException e) {
        e.printStackTrace();
    }


    /**
     * Updating parsed JSON data into ListView
     * */
    ListAdapter adapter = new SimpleAdapter(this, contactList,
            R.layout.activity_home,
            new String[] { TAG_TITLE, TAG_DATE, TAG_NAME, TAG_CONTENT }, new int[] {
                    R.id.name, R.id.email,R.id.mobile,R.id.content});

    setListAdapter(adapter);

    // selecting single ListView item
    ListView lv = getListView();

    // Launching new screen on Selecting Single ListItem
    lv.setOnItemClickListener(new OnItemClickListener() {

        public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {
            // getting values from selected ListItem
            String title = ((TextView) view.findViewById(R.id.name)).getText().toString();
            String date = ((TextView) view.findViewById(R.id.email)).getText().toString();
            String name = ((TextView) view.findViewById(R.id.mobile)).getText().toString();
            String content = ((TextView) view.findViewById(R.id.content)).getText().toString();

            // Starting new intent
            Intent in = new Intent(getApplicationContext(), Singlemenuitem.class);
            in.putExtra(TAG_TITLE, title);
            in.putExtra(TAG_DATE, date);
            in.putExtra(TAG_NAME, name);
            in.putExtra(TAG_CONTENT, content);
            startActivity(in);

        }
    });

Answer 1

There's alot of ways you can accomplish this, one pretty straight forward way would be to store the result of the json call in some sort of list structure. Now, introduce another datastructure which shows a subset of the results list, you could use an ArrayAdapter, with offers both clear(), add(), insert() and remove() methods to manipulate the underlying data-structure.

Then, a search would consist of

1. iterating over your results data structure
2. updating your visibleResults data structure as you go along
3. notify the view that the array adapter has changed using notifyDataSetChanged

Or, if you are feeling fancy, you could cache the results of the json query in a sqlite database, and use a CursorAdapter instead. Depending on the complexity of your queries, and the amount of data concerned, this might be overkill though.