CODEWITHSUNDEEP
androidlistviewscrolladapter
peppermcknight
peppermcknight

Reputation: 85

Android ListView Only Showing Items after Scrolling

I am building an Android app, and as part of it I am displaying a list on songs with checkboxes to allow for selection. I am using a custom list adapter to do this. The code seems to load and works with the checkboxes, but the only problem I am having is that only the very top item in the listview shows the text until I scroll down the list, then the other items render the text.

I am aware that it might be a problem with the listview not refreshing or something like that but I can't figure out how to fix it.

Heres the code for my adapter:

private class PlaylistDetailsAdapter extends ArrayAdapter<Song> {

    boolean[] checkBoxState;
    ViewHolder viewHolder;

    public PlaylistDetailsAdapter(Context context, int textViewResourceId, ArrayList<Song> songs) {
        super(context, textViewResourceId, songs);
        checkBoxState = new boolean[songs.size()];
    }

    private class ViewHolder {
        TextView songName;
        CheckBox checkBox;
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        if (convertView == null) {
            convertView = inflater.inflate(R.layout.activity_playlist_details_row, null);
            viewHolder = new ViewHolder();

            viewHolder.songName = (TextView)convertView.findViewById(R.id.playlist_details_song_name);
            viewHolder.checkBox = (CheckBox)convertView.findViewById(R.id.playlist_details_checkbox);
            convertView.setTag(viewHolder);
        }
        else {
            viewHolder = (ViewHolder)convertView.getTag();
            Song song = playlistSongs.get(position);
            viewHolder.songName.setText(song.getTitle() + " - " + song.getArtist());
            viewHolder.checkBox.setChecked(checkBoxState[position]);
            viewHolder.checkBox.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    if (((CheckBox)v).isChecked()) {
                        checkBoxState[position] = true;
                    }
                    else {
                        checkBoxState[position] = false;
                    }
                }
            });

        }

        return convertView;
    }

}

This is the code to set up the list view:

playlistSongs = db.getPlaylistTracks(getIntent().getLongExtra("id", 0));

    TextView playlistName = (TextView)findViewById(R.id.playlist_details_name);
    playlistName.setText(getIntent().getStringExtra("name"));

    final PlaylistDetailsAdapter adapter = new PlaylistDetailsAdapter(this, R.layout.activity_playlist_details_row, playlistSongs);

    ListView playlistSongList = (ListView)findViewById(R.id.listview_playlist_details);

    playlistSongList.setAdapter(adapter);

Any help would be greatly appreciated.

Thanks

Upvotes: 3

Views: 6301

Answers (3)

Brajendra Pandey
Brajendra Pandey

Reputation: 2274

Hi friend you can use horizontal or vertical scroll view to remove this problem as you know that list-view is recycled every time.

I am also faced this problem before than i use scroll in comparison to listview

then create a Boolean arrayList of as the size of your list item and set all the value false first. after that u can use your code

           @Override
            public void onClick(View v) {
                if (((CheckBox)v).isChecked()) {
                    checkBoxState[position] = true;
                }
                else {
                    checkBoxState[position] = false;
                }
            }
        });

Upvotes: 0

android developer
android developer

Reputation: 116332

The problem is that you don't put the data into the views when the convertView==null , You only set how to find them .

What you need to do is to remove from the "else" part , the code that actually change the views , and put it right after the whole if-else area .

example :

@Override
public View getView(final int position, View convertView, ViewGroup parent) {
    if (convertView == null) {
     ...
    }
    else 
        viewHolder = (ViewHolder)convertView.getTag();
    // now we have the views ready to be changed , so change them :
    Song song = playlistSongs.get(position);
    ...
    return convertView;
}

Upvotes: 5

Tom Mekken
Tom Mekken

Reputation: 1039

call: 

adapter.notifyDataSetChanged()

when your list contains new data

Upvotes: 0

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