I wasn't able to get the AsyncTask to work (although I have used it
successfully in another app). What I did was use the Looper.prepare();
in my run() method:
public void run(){
Looper.prepare();
loadsongs(CURRENT_PLAYLIST);
mHandler = new Handler() {
@Override
public void handleMessage(Message msg){
// refresh the listing of playlists
}
};
Looper.loop();
}
It doesn't crash, but it doesn't show the refresh of the listview
either -- but I think the listview is being refreshed. I have to leave
the activity and return to it to see the update.
On Feb 18, 10:43 am, Frank Weiss <[email protected]> wrote:
> 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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