I am trying to access a list-activity using custom adapter.I have tried it directly without using any custom adapter it was working good but because I want to add more functions in list-view I want to implement a custom adapter.Now I have tried it but I am getting an empty list-view with no data visible. List-Activity
public class MainActivity extends ListActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String selection = MediaStore.Audio.Media.IS_MUSIC + " != 0";
String[] projection = {
MediaStore.Audio.Media._ID,
MediaStore.Audio.Media.ARTIST,
MediaStore.Audio.Media.TITLE,
MediaStore.Audio.Media.DATA,
MediaStore.Audio.Media.DISPLAY_NAME,
MediaStore.Audio.Media.DURATION,
};
//query
musiccursor = this.managedQuery(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,projection,selection,null,sortOrder);
music_column_index = musiccursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DATA);
int a[]= new int[]{R.id.TitleSong,R.id.Artist};
Custom_Adapter adapter = new Custom_Adapter(this,R.layout.music_items, musiccursor, new String[]{MediaStore.Audio.Media.TITLE,MediaStore.Audio.Media.ARTIST} ,a);
this.setAdapter(adapter);
}
}
Custom-Adapter
public class Custom_Adapter extends SimpleCursorAdapter {
private Context mContext;
private Context appContext;
private int layout;
private Cursor cr;
private final LayoutInflater inflater;
public Custom_Adapter(Context context,int layout, Cursor c,String[] from,int[] to) {
super(context,layout,c,from,to);
this.layout=layout;
this.mContext = context;
this.inflater=LayoutInflater.from(context);
this.cr=c;
}
@Override
public void bindView(View view, Context context, Cursor cursor) {
// TODO Auto-generated method stub
super.bindView(view, context, cursor);
view=inflater.inflate(layout, null, false);
TextView titleS=(TextView)view.findViewById(R.id.TitleSong);
TextView artistS=(TextView)view.findViewById(R.id.Artist);
int Title_index;
int Artist_index;
cursor.moveToFirst();
while(cursor.isLast()){
Title_index=cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DISPLAY_NAME);
Artist_index=cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.ARTIST);
titleS.setText(cursor.getString(Title_index));
artistS.setText(cursor.getString(Artist_index));
cr.moveToNext();
}
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
return convertView;
}
}
1) CursorAdapterIn BaseAdapter, view is created in getView method; in CursorAdapter, however, view is created in newView() method and elements are populated in bindView(). In the newView() method, you simply inflate the view your custom xml and return it. In the bindView() method, you set the elements of your view.
An easy adapter to map columns from a cursor to TextViews or ImageViews defined in an XML file. You can specify which columns you want, which views you want to display the columns, and the XML file that defines the appearance of these views.
In Android, Adapter is a bridge between UI component and data source that helps us to fill data in UI component. It holds the data and send the data to an Adapter view then view can takes the data from the adapter view and shows the data on different views like as ListView, GridView, Spinner etc.
You can use this adapter to provide views for an AdapterView , Returns a view for each object in a collection of data objects you provide, and can be used with list-based user interface widgets such as ListView or Spinner .
When extending a cursor adapter you should override the methods bindView and newView. The bindView method is used to bind all data to a given view such as setting the text on a TextView. The newView method is used to inflate a new view and return it, you don't bind any data to the view at this point. Most adapters use the getView function but when extending a cursor adapter you should use bindView and newView.
public class Custom_Adapter extends SimpleCursorAdapter {
private Context mContext;
private Context appContext;
private int layout;
private Cursor cr;
private final LayoutInflater inflater;
public Custom_Adapter(Context context,int layout, Cursor c,String[] from,int[] to) {
super(context,layout,c,from,to);
this.layout=layout;
this.mContext = context;
this.inflater=LayoutInflater.from(context);
this.cr=c;
}
@Override
public View newView (Context context, Cursor cursor, ViewGroup parent) {
return inflater.inflate(layout, null);
}
@Override
public void bindView(View view, Context context, Cursor cursor) {
super.bindView(view, context, cursor);
TextView titleS=(TextView)view.findViewById(R.id.TitleSong);
TextView artistS=(TextView)view.findViewById(R.id.Artist);
int Title_index=cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DISPLAY_NAME);
int Artist_index=cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.ARTIST);
titleS.setText(cursor.getString(Title_index));
artistS.setText(cursor.getString(Artist_index));
}
}
you better write these lines of code in your customadapter
getview
function. It work for me and will work for you, it's simple.
if (convertView == null) {
music_column_index = myCursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DISPLAY_NAME);
myCursor.moveToPosition(position);
id = myCursor.getString(music_column_index);
music_column_index = myCursor.getColumnIndexOrThrow(MediaStore.Audio.Media.SIZE);
myCursor.moveToPosition(position);
id += " Size(KB):" + myCursor.getString(music_column_index);
Log.d("TAG", "id::" + id);
tv.setText(id);
} else
tv = (TextView) convertView;
return tv;
}
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