【发布时间】：2011-09-23 10:44:59
【问题描述】：
我是 Android 的初学者，但我尝试进行自定义列表视图过滤，但它以某种方式工作。我唯一的问题是我保留所有值的 ArrayList （“原始” ArrayList ）在每次过滤中的项目上越来越低。我无法解释这一点，但我认为您可以以某种方式帮助我。
无论如何这里是自定义 ArrayAdaptor：
public class PkmnAdapter extends ArrayAdapter<Pkmn> {
private ArrayList<Pkmn> original;
private ArrayList<Pkmn> fitems;
private Filter filter;
public PkmnAdapter(Context context, int textViewResourceId, ArrayList<Pkmn> items) {
super(context, textViewResourceId, items);
this.original = items;//new ArrayList<Pkmn>();
this.fitems = items;//new ArrayList<Pkmn>();
}
@Override
public void add(Pkmn item){
original.add(item);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View v = convertView;
if (v == null) {
LayoutInflater vi = (LayoutInflater)getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = vi.inflate(R.layout.row, null);
}
Pkmn pkmn = original.get(position);
if (pkmn != null) {
TextView tt = (TextView) v.findViewById(R.id.RlabPName);
TextView dex = (TextView)v.findViewById(R.id.RlabDex);
ImageView img = (ImageView)v.findViewById(R.id.RimgPkmn);
if (tt != null) { tt.setText(pkmn.getName()); }
if (dex != null){ dex.setText(CalcDex(pkmn.getId())); }
if (img != null){
int resId = getContext().getResources().getIdentifier("dex" + pkmn.getId(), "drawable", "com.compileguy.pokebwteam");
img.setImageResource(resId);
}
}
return v;
}
@Override
public Filter getFilter()
{
if (filter == null)
filter = new PkmnNameFilter();
return filter;
}
private class PkmnNameFilter extends Filter
{
@Override
protected FilterResults performFiltering(CharSequence constraint)
{
FilterResults results = new FilterResults();
String prefix = constraint.toString().toLowerCase();
if (prefix == null || prefix.length() == 0)
{
ArrayList<Pkmn> list = new ArrayList<Pkmn>(original);
results.values = list;
results.count = list.size();
}
else
{
final ArrayList<Pkmn> list = original;
int count = list.size();
final ArrayList<Pkmn> nlist = new ArrayList<Pkmn>(count);
for (int i=0; i<count; i++)
{
final Pkmn pkmn = list.get(i);
final String value = pkmn.getName().toLowerCase();
if (value.startsWith(prefix))
{
nlist.add(pkmn);
}
}
results.values = nlist;
results.count = nlist.size();
}
return results;
}
@SuppressWarnings("unchecked")
@Override
protected void publishResults(CharSequence constraint, FilterResults results) {
fitems = (ArrayList<Pkmn>)results.values;
clear();
int count = fitems.size();
for (int i=0; i<count; i++)
{
Pkmn pkmn = (Pkmn)fitems.get(i);
add(pkmn);
}
if (fitems.size() > 0)
notifyDataSetChanged();
else
notifyDataSetInvalidated();
}
}
private String CalcDex(int id){
String s = String.valueOf(id);
if (s.length() == 1)
s = "00"+s;
else if (s.length() == 2)
s = "0"+s;
return '#'+s;
}
}
注意：列表视图正确显示了项目，但是当我删除编辑框中的一个字母（触发过滤）时，这就是问题的开始。
--- 编辑 ---
@Janusz：非常感谢您的回答。这解决了我的问题。
这是对我有用的源代码，所以如果有人有同样的问题，他们可以试试这个：
private ArrayList<Pkmn> original;
private ArrayList<Pkmn> fitems;
private Filter filter;
public PkmnAdapter(Context context, int textViewResourceId, ArrayList<Pkmn> items) {
super(context, textViewResourceId, items);
this.original = new ArrayList<Pkmn>(items);
this.fitems = new ArrayList<Pkmn>(items);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View v = convertView;
if (v == null) {
LayoutInflater vi = (LayoutInflater)getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = vi.inflate(R.layout.row, null);
}
Pkmn pkmn = fitems.get(position);
if (pkmn != null) {
TextView tt = (TextView) v.findViewById(R.id.RlabPName);
TextView dex = (TextView)v.findViewById(R.id.RlabDex);
ImageView img = (ImageView)v.findViewById(R.id.RimgPkmn);
if (tt != null) { tt.setText(pkmn.getName()); }
if (dex != null){ dex.setText(CalcDex(pkmn.getId())); }
if (img != null){
int resId = getContext().getResources().getIdentifier("dex" + pkmn.getId(), "drawable", "com.compileguy.pokebwteam");
img.setImageResource(resId);
}
}
return v;
}
@Override
public Filter getFilter()
{
if (filter == null)
filter = new PkmnNameFilter();
return filter;
}
private class PkmnNameFilter extends Filter
{
@Override
protected FilterResults performFiltering(CharSequence constraint)
{
FilterResults results = new FilterResults();
String prefix = constraint.toString().toLowerCase();
if (prefix == null || prefix.length() == 0)
{
ArrayList<Pkmn> list = new ArrayList<Pkmn>(original);
results.values = list;
results.count = list.size();
}
else
{
final ArrayList<Pkmn> list = new ArrayList<Pkmn>(original);
final ArrayList<Pkmn> nlist = new ArrayList<Pkmn>();
int count = list.size();
for (int i=0; i<count; i++)
{
final Pkmn pkmn = list.get(i);
final String value = pkmn.getName().toLowerCase();
if (value.startsWith(prefix))
{
nlist.add(pkmn);
}
}
results.values = nlist;
results.count = nlist.size();
}
return results;
}
@SuppressWarnings("unchecked")
@Override
protected void publishResults(CharSequence constraint, FilterResults results) {
fitems = (ArrayList<Pkmn>)results.values;
clear();
int count = fitems.size();
for (int i=0; i<count; i++)
{
Pkmn pkmn = (Pkmn)fitems.get(i);
add(pkmn);
}
}
}
}
【问题讨论】：
-
'clear()' 和 'add()' 函数的作用是什么。
-
@compileGuy，“Pkmn”是什么意思？我无法运行此示例。你能完整上传代码吗？
-
优秀的实现@compileguy，添加和清除是适配器的功能，你不需要覆盖它们。 pkmn 是一个模型类，用于保存列表中的数据值
-
您的代码与我的 (stackoverflow.com/questions/20524417/…) 有何匹配？我还是有问题：/
-
如何在列表视图中设置适配器 @kkanellis
标签： android filter android-listview android-arrayadapter