Una vez implementé un filtro como el código anterior usando notifyDataSetChanged()
y no tuve problemas con él.
También he modificado las vistas de una lista sobre la marcha de forma manual. Ambos han funcionado bien. En algún caso prefiero modificar los datos manualmente porque es más rápido y porque no afecta a toda la lista.
De todos modos, las vistas son creados sobre la marcha cuando tienen que apear en la pantalla y se eliminan al salir de la pantalla, por lo que si modifica los datos utilizados para crear los puntos de vista, si el usuario se desplaza el ListView y las vistas salga de la pantalla, en teoría, las vistas se crearán con los nuevos datos una vez que vuelvan a aparecer en la pantalla.
Le recomendaría que pruebe el siguiente código para comprender cómo funciona notifyDataSetChanged()
y decida si le conviene.
public class ListText extends Activity {
private ListView lv1;
private Followed followedFriends[];
ListView lst;
EditText edt;
FollowedFilterableAdapter arrad;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
lv1=(ListView)findViewById(R.id.listView1);
edt = (EditText) findViewById(R.id.editText1);
followedFriends = new Followed[10];
followedFriends[0] = new Followed("Alan Walder", "", "1");
followedFriends[1] = new Followed("Alberto Levi", "123456789", "1");
followedFriends[2] = new Followed("David Rodan", "23456789", "1");
followedFriends[3] = new Followed("David Stern", "3456789", "1");
followedFriends[4] = new Followed("Elias Jawa", "456789", "1");
followedFriends[5] = new Followed("Elian Moreno", "56789", "1");
followedFriends[6] = new Followed("Jonathan Rodan", "6789", "1");
followedFriends[7] = new Followed("Klara Rodan", "789", "1");
followedFriends[8] = new Followed("Willy Rosales", "89", "1");
followedFriends[9] = new Followed("ZZZ ZZZ", "9", "1");
arrad = new FollowedFilterableAdapter(followedFriends);
lv1.setAdapter(arrad);
addTextChangeList();
}
private void addTextChangeList()
{
edt.addTextChangedListener(new TextWatcher()
{
public void onTextChanged(CharSequence arg0, int arg1, int arg2, int arg3)
{
// TODO Auto-generated method stub
}
public void beforeTextChanged(CharSequence arg0, int arg1, int arg2, int arg3)
{
// TODO Auto-generated method stub
}
public void afterTextChanged(Editable arg0)
{
// TODO Auto-generated method stub
ListText.this.arrad.getFilter().filter(arg0);
}
});
}
///////////////////////////////////Internal classes ////////////////////////
private class Followed
{
private String _name;
private String _id;
private boolean _followed;
private String _picToDelete = "http://images.wikia.com/tibia/en/images/7/72/Skeleton.gif";
private Followed(String name, String id, String followed)
{
this._name = name;
this._id = id;
this._followed = followed.equals("1");
}
public String toString(){return _name;}
public String getName(){return _name;}
public String getId(){return _id;}
public boolean idFollowed(){return _followed;}
public String getURL(){return _picToDelete;}
}
/////////////////////////////////////////Adapter//////////////////////////////////
private class FollowedFilterableAdapter extends BaseAdapter implements Filterable
{
/**
* Lock used to modify the content of {@link #mObjects}. Any write operation
* performed on the array should be synchronized on this lock. This lock is also
* used by the filter (see {@link #getFilter()} to make a synchronized copy of
* the original array of data.
*/
private final Object _Lock = new Object();
/*/**
* Indicates whether or not {@link #notifyDataSetChanged()} must be called whenever
* {@link #mObjects} is modified.
*/
//private boolean _NotifyOnChange = true;
private List<Followed> _Objects;
private ArrayList<Followed> _followedFriends;
private ArrayFilter _Filter;
public FollowedFilterableAdapter(Followed[] followedFriends)
{
_Objects = Arrays.asList(followedFriends);
}
public int getCount() {
return _Objects.size();
}
public Followed getItem(int position) {
return _Objects.get(position);
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
int px = 2;
//Creating the CategoryRow that represents the row
LinearLayout lstItem = new LinearLayout(ListText.this);
lstItem.setLayoutParams(new ListView.LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT,1));
lstItem.setOrientation(LinearLayout.HORIZONTAL);
//lstItem.setPadding(px,px,px,px);
lstItem.setGravity(Gravity.CENTER_VERTICAL);
/*<LinearLayout android:layout_width="fill_parent"
android:layout_height="wrap_content" android:orientation="horizontal"
android:padding="2dp" android:gravity="center_vertical">*/
//Adding the Image
ImageView icon = new ImageView(ListText.this);
icon.setLayoutParams(new LayoutParams(50,50));
icon.setImageResource(R.drawable.icon);
icon.setScaleType(ScaleType.CENTER_CROP);
//icon.setImage(tag.getId());
/*<ImageView android:layout_width="50dp" android:id="@+id/iconFollList"
android:src="@drawable/icon" android:layout_height="40dp"></ImageView>*/
//Adding the Linear Layout for the text
RelativeLayout lstTextx = new RelativeLayout(ListText.this);
lstTextx.setLayoutParams(new LinearLayout.LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT,1));
lstTextx.setGravity(Gravity.CENTER_VERTICAL);
lstTextx.setPadding(5, px, px, px);
/*<LinearLayout android:layout_width="fill_parent"
android:layout_height="wrap_content" android:orientation="vertical"
android:padding="2dp" android:paddingLeft="5dp">*/
//Adding the Name of the person who commented
TextView txtCommenter = new TextView(ListText.this);
txtCommenter.setLayoutParams(
new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT));
txtCommenter.setTextSize(10);
txtCommenter.setTypeface(Typeface.create("Sans Serif", Typeface.BOLD));
txtCommenter.setText(_Objects.get(position).getName());
/*<TextView android:text="TextView" android:id="@+id/FollListCategory"
android:layout_width="wrap_content" android:layout_height="wrap_content"></TextView>*/
ImageView btnFollowed = new ImageView(ListText.this);
RelativeLayout.LayoutParams params =
new RelativeLayout.LayoutParams(80,30);
params.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
btnFollowed.setLayoutParams(params);
btnFollowed.setImageResource(R.drawable.icon);
btnFollowed.setScaleType(ScaleType.FIT_XY);
//Arming the View
lstItem.addView(icon, 0);
lstTextx.addView(txtCommenter, 0);
lstTextx.addView(btnFollowed,1);
lstItem.addView(lstTextx,1);
return lstItem;
}
/**
* {@inheritDoc}
*/
@Override
public void notifyDataSetChanged() {
super.notifyDataSetChanged();
//_NotifyOnChange = true;
}
/*public void setNotifyOnChange(boolean notifyOnChange) {
_NotifyOnChange = notifyOnChange;
}*/
public Filter getFilter() {
if (_Filter == null) {
_Filter = new ArrayFilter();
}
return _Filter;
}
/////////////////////Second Level Internal classes //////////////////////////
private class ArrayFilter extends Filter {
@Override
protected FilterResults performFiltering(CharSequence prefix) {
FilterResults results = new FilterResults();
if (_followedFriends == null) {
synchronized (_Lock) {
_followedFriends = new ArrayList<Followed>(_Objects);
}
}
if (prefix == null || prefix.length() == 0) {
synchronized (_Lock) {
ArrayList<Followed> list = new ArrayList<Followed>(_followedFriends);
results.values = list;
results.count = list.size();
}
} else {
String prefixString = prefix.toString().toLowerCase();
final ArrayList<Followed> values = _followedFriends;
final int count = values.size();
final ArrayList<Followed> newValues = new ArrayList<Followed>(count);
for (int i = 0; i < count; i++) {
final Followed value = values.get(i);
final String valueText = value.toString().toLowerCase();
// First match against the whole, non-splitted value
if (valueText.startsWith(prefixString)) {
newValues.add(value);
} else {
final String[] words = valueText.split(" ");
final int wordCount = words.length;
for (int k = 0; k < wordCount; k++) {
if (words[k].startsWith(prefixString)) {
newValues.add(value);
break;
}
}
}
}
results.values = newValues;
results.count = newValues.size();
}
return results;
}
@Override
protected void publishResults(CharSequence constraint, FilterResults results) {
//no inspection unchecked
_Objects = (List<Followed>) results.values;
if (results.count > 0) {
notifyDataSetChanged();
} else {
notifyDataSetInvalidated();
}
}
}
}
xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<EditText android:text="" android:layout_height="wrap_content"
android:id="@+id/editText1" android:layout_width="match_parent"></EditText>
<ListView android:id="@+id/listView1" android:layout_height="fill_parent"
android:layout_width="match_parent" android:layout_weight="1"></ListView>
</LinearLayout>
Espero que esto ayude.
Un ListView no contiene una vista para cada objeto en su adaptador. Las vistas se vuelven a usar, por lo que las vistas visibles son las únicas que hay. Entonces su implementación no está optimizando nada. – pgsandstrom
Usted debe mirar en el patrón de adaptadores ViewHolder –