Use AsyncTask instead od Java threads. I'm not kidding, it's that simple.
On Thu, Feb 18, 2010 at 10:21 AM, Ken H <[email protected]> wrote:
> What am I doing wrong here? I have a listview of items (songs on the
> sd card). The user has an option to load all the songs on the sd card
> to into a current playlist -- those songs are what is displayed in the
> listview. Because this can take few seconds to load if they have a lot
> of songs on the card, I want to display a progress dialog to just tell
> the user "One moment..." until the list refresh is done.
>
> I launch a thread to do this. I've done this successfully on another
> app I have (which just updates a database in the background but
> doesn't update any display), but this one fails with this error
> message, "Can't create handler inside thread that has not called
> Looper.prepare()". I chopped down the activity and pasted it below.
> What am I doing wrong here? I have just a vague idea of what might be
> happening.
>
> By the way, everything works when I take out the threaded stuff, it
> just looks like the app freezes for a couple seconds.
>
> Ken
>
> /
>
> ************************************************************************************************/
>
> public class ListingThing extends ListActivity implements Runnable {
> public static final String PREF_NAME = "PlaylistAlarmPreferences";
> static final private int CONFIGURE_PLAYLIST = Menu.FIRST;
> static final private int DELETE_LIST = Menu.FIRST+1;
> static final private int DELETE_SONG = Menu.FIRST;
> static final private int LOAD_ALL = Menu.FIRST+2;
> String playlistName, CURRENT_PLAYLIST;
> SharedPreferences settings;
> String[] items, subitems, fullpath;
> int DRILL_DOWN_LEVEL, resultCount;
> MediaPlayer mMediaPlayer;
> ProgressDialog myProgressDialog;
>
> /** Called when the activity is first created. */
> @Override
> public void onCreate(Bundle savedInstanceState) {
> super.onCreate(savedInstanceState);
>
> mMediaPlayer = new MediaPlayer();
>
> getListOfPlaylists();
> setListAdapter(new MySpecialAdapter(this));
> // you need this for the contextmenu
> registerForContextMenu(getListView());
> }
>
> public void getListOfPlaylists(){
> // query db for list of songs
> }
>
> class MySpecialAdapter extends ArrayAdapter {
> Activity context;
>
> MySpecialAdapter(Activity context) {
> super(context, R.layout.double_list_item, items);
> this.context=context;
> }
>
> public View getView(int position, View convertView, ViewGroup
> parent) {
> View row=convertView;
>
> if (row==null) {
> LayoutInflater inflater=context.getLayoutInflater();
> row=inflater.inflate(R.layout.double_list_item,
> null);
> }
>
> TextView text1 = (TextView)row.findViewById(R.id.maintext);
> text1.setText(items[position]);
> TextView text2 = (TextView)row.findViewById(R.id.subtext);
> text2.setText(subitems[position]);
> row.setSoundEffectsEnabled(true);
>
> return row;
> }
> }
>
> // This handles a context menu item click
> @Override
> public boolean onContextItemSelected(MenuItem item) {
> AdapterContextMenuInfo info = (AdapterContextMenuInfo)
> item.getMenuInfo();
> Object n = this.getListAdapter().getItemId((int)info.id);
> final String pos = n.toString(); // get the item number of
> selection
>
> myProgressDialog = ProgressDialog.show(this,
> "One moment...", "Refreshing list of songs in
> playlist.", true);
> CURRENT_PLAYLIST = items[Integer.parseInt(pos)];
> Thread t = new Thread(this);
> t.start();
>
> return super.onContextItemSelected(item);
> }
>
> public void run(){
> loadsongs(CURRENT_PLAYLIST);
> handler.sendEmptyMessage(0);
> }
>
> private Handler handler = new Handler() {
> @Override
> public void handleMessage(Message msg){
> myProgressDialog.dismiss();
> // refresh the listing of playlists
> getListOfPlaylists();
> setListAdapter(new MySpecialAdapter(ListingThing.this));
>
> }
> };
>
> // delete all songs in playlist and then reload all songs into it
> private void loadsongs(String pl){
> try{
> Uri media =
> MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
> DBAdapter db_songs = new
> DBAdapter(ListingThing.this);
>
> String[] projection = {
> // The columns we want
> MediaStore.Audio.Media._ID,
> // 0
> MediaStore.Audio.Media.ARTIST,
> // 1 artist
> MediaStore.Audio.Media.TITLE,
> // 2 song
> MediaStore.Audio.Media.DATA,
> // 3 full path of file "/sdcard/In
> Da Club.mp3"
> MediaStore.Audio.Media.DISPLAY_NAME, // 4
> "In Da Club.mp3"
> MediaStore.Audio.Media.DURATION};
> // 5 time in milliseconds
>
> String selection = MediaStore.Audio.Media.IS_MUSIC +
> " != 0";
> Cursor c = this.managedQuery(media, projection,
> selection, null,
> null);
>
> db_songs.open();
> db_songs.deletePlaylist(pl); // delete all songs
> in playlist first
> if (c.moveToFirst()){
> do {
> db_songs.insertPoint(
> pl,
> c.getString(1),
> c.getString(2),
> c.getString(3),
> c.getString(4),
> c.getString(5),
> 0);
> }while (c.moveToNext());
> }
> resultCount = c.getCount();
> db_songs.close();
> c.close();
> Toast.makeText(ListingThing.this,
> "All songs on the SD card where
> added to the playlist
> '"+playlistName+"'",
> Toast.LENGTH_LONG).show();
>
> }catch(Exception e){
> Toast.makeText(ListingThing.this,
> "Error loading all songs to playlist.\n:
> "+e,
> Toast.LENGTH_LONG).show();
> }
>
> }
> }
>
>
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