使用 arrayadapter 来 filter 一个 listview

原问题来自于CSDN问答频道，更多解决方案见：http://ask.csdn.net/questions/1679

问题描述：

我使用 arrayadapter 来 filter 一个 listview。Arraydapter 的参数是一个String[][]。但是没有成功，必须要重写 Filter interface吗？要是这样的话，如何重写呢？

filter 数组的每一个位置：

galleryValues[0][0] -> "tiulo" [0][1] -> "desc" [0][2] -> "etc"
lstContinente = (ListView)findViewById(R.id.list);
lstContinente.setTextFilterEnabled(true);
adapter = new PortaitArrayAdapter(cx,galleryValues);
lstContinente.setAdapter(adapter);

ed_busqueda.addTextChangedListener(new TextWatcher() {
public void afterTextChanged(Editable s) {}
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
// TODO Auto-generated method stub
}
public void onTextChanged(CharSequence s, int start, int before, int count) {
adapter.getFilter().filter(s.toString());
adapter.notifyDataSetChanged();
}
});

The adapter code:

public class PortaitArrayAdapter extends ArrayAdapter<String> {
private final Context context;
private final String[][] values;
private List<Imagen> imagenes = null;
private LayoutInflater mInflater;
public ImageLoader imageLoader;
public PortaitArrayAdapter(Context context, String[][] values) {
super(context, R.layout.gallery_row);
this.context = context;
this.values = values;
mInflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
imagenes = new ArrayList<Imagen>();
for (int i = 0; i < 20; i++) imagenes.add(new Imagen());
Bitmap def = BitmapFactory.decodeResource(this.context.getResources(),R.drawable.ic_launcher);
imageLoader=new ImageLoader(this.context,def, imagenes);
}
@Override
public int getCount (){
return this.values.length;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
holder = new ViewHolder();
convertView =  mInflater.inflate(R.layout.gallery_row, parent, false);
holder.txtTitulo = (TextView) convertView.findViewById(R.id.txt_gallery_titulo);
holder.txtDesc = (TextView) convertView.findViewById(R.id.txt_gallery_desc);
holder.txtFecha = (TextView) convertView.findViewById(R.id.txt_gallery_fecha);
holder.txtEst = (TextView) convertView.findViewById(R.id.txt_gallery_est);
holder.imageView    = (ImageView)convertView.findViewById(R.id.lst_img_gallery);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
/*LayoutInflater inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View rowView = inflater.inflate(R.layout.gallery_row, parent, false);*/

//ImageView imageView = (ImageView) rowView.findViewById(R.id.icon);
Bitmap bmp;
Log.v("Position --> ",String.valueOf(position));
try {
byte b[] = imagenes.get(position).getImageData();
if (b != null) {
bmp = BitmapFactory.decodeByteArray(b, 0, b.length);
if (bmp != null) holder.imageView.setImageBitmap(bmp);
} else {
String urlBase = galleryValues[position][0].substring(0, galleryValues[position][0].lastIndexOf("/")+1);
String urlToEncode = galleryValues[position][0].substring(galleryValues[position][0].lastIndexOf("/")+1, galleryValues[position][0].length());
urlToEncode = URLEncoder.encode(urlToEncode,"UTF-8");
String url = urlBase.concat(urlToEncode);
url = url.replace("+", "%20");
Log.v("UrlFinal --> ",url);
imageLoader.DisplayImage(String.valueOf(position),url,act,holder.imageView, position,null);
}
} catch (Exception e) {
Log.e(this.getClass().getName(),"Exception en pos = " + position + " error:" + e.getMessage());
e.printStackTrace();
}
holder.txtTitulo.setText(galleryValues[position][1] + ", " + galleryValues[position][2]);
String[] dates = galleryValues[position][4].split("/");
String date = dates [1] + "/" + dates[0] + "/" + dates[2];
Date d1 = new Date(date);
DateFormat df = DateFormat.getDateInstance(DateFormat.LONG);
holder.txtDesc.setText(galleryValues[position][3]);
holder.txtFecha.setText(df.format(d1));
holder.txtEst.setText(getText(R.string.num_fotos_gallery) + galleryValues[position][5] + " - " + getText(R.string.num_videos_gallery) + galleryValues[position][6] + " - " + getText(R.string.num_exp_gallery) + galleryValues[position][7]);
return convertView;
}
}
private static class ViewHolder {
TextView txtTitulo;
TextView txtDesc;
TextView txtFecha;
TextView txtEst;
ImageView imageView;
}

解决方案：

把字符串数组放在 ArrayList 中，然后把它传递到 Adapter。使用下面的代码或者用 String[]更改下面的代码。

需要在 Adapter 类中实现 Filterable ，重写 getFilter()。

参考下面的代码关于 Filtering custom Adapter.

public class ListFilterActivity extends ListActivity {

private List<String> list = new ArrayList<String>();
List<String> mOriginalValues;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

final MyAdapter adapter = new MyAdapter(this, getModel());
setListAdapter(adapter);

EditText filterEditText = (EditText) findViewById(R.id.filterText);

// Add Text Change Listener to EditText
filterEditText.addTextChangedListener(new TextWatcher() {

@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
// Call back the Adapter with current character to Filter
adapter.getFilter().filter(s.toString());
}

@Override
public void beforeTextChanged(CharSequence s, int start, int count,int after) {
}

@Override
public void afterTextChanged(Editable s) {
}
});
}

private List<String> getModel() {
list.add("Linux");
list.add("Windows7");
list.add("Suse");
list.add("Eclipse");
list.add("Ubuntu");
list.add("Solaris");
list.add("Android");
list.add("iPhone");
list.add("Windows XP");
return list;
}

// Adapter Class
public class MyAdapter extends BaseAdapter implements Filterable {

List<String> arrayList;
List<String> mOriginalValues; // Original Values
LayoutInflater inflater;

public MyAdapter(Context context, List<String> arrayList) {
this.arrayList = arrayList;
inflater = LayoutInflater.from(context);
}

@Override
public int getCount() {
return arrayList.size();
}

@Override
public Object getItem(int position) {
return position;
}

@Override
public long getItemId(int position) {
return position;
}

private class ViewHolder {
TextView textView;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {

ViewHolder holder = null;

if (convertView == null) {

holder = new ViewHolder();
convertView = inflater.inflate(R.layout.row, null);
holder.textView = (TextView) convertView
.findViewById(R.id.textview);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.textView.setText(arrayList.get(position));
return convertView;
}

@Override
public Filter getFilter() {
Filter filter = new Filter() {

@SuppressWarnings("unchecked")
@Override
protected void publishResults(CharSequence constraint,FilterResults results) {

arrayList = (List<String>) results.values; // has the filtered values
notifyDataSetChanged();  // notifies the data with new filtered values
}

@Override
protected FilterResults performFiltering(CharSequence constraint) {
FilterResults results = new FilterResults();        // Holds the results of a filtering operation in values
List<String> FilteredArrList = new ArrayList<String>();

if (mOriginalValues == null) {
mOriginalValues = new ArrayList<String>(arrayList); // saves the original data in mOriginalValues
}

/********
*
*  If constraint(CharSequence that is received) is null returns the mOriginalValues(Original) values
*  else does the Filtering and returns FilteredArrList(Filtered)
*
********/
if (constraint == null || constraint.length() == 0) {

// set the Original result to return
results.count = mOriginalValues.size();
results.values = mOriginalValues;
} else {
constraint = constraint.toString().toLowerCase();
for (int i = 0; i < mOriginalValues.size(); i++) {
String data = mOriginalValues.get(i);
if (data.toLowerCase().startsWith(constraint.toString())) {
FilteredArrList.add(data);
}
}
// set the Filtered result to return
results.count = FilteredArrList.size();
results.values = FilteredArrList;
}
return results;
}
};
return filter;
}
}
}