我是android新手。 我有一个XML文件，我试图使用Java进行搜索。 （问题出在编辑文本中）。
我如何进行从编辑文本中获取文本并在listview中过滤结果的搜索？ 这是我的代码：
package com.search.xmlParsing;
public class MainActivity extends ListActivity {
public static final String LOGTAG = "EXPLORECA";
public static final String USERNAME = "pref_username";
public static final String VIEWIMAGE = "pref_viewimages";
private static final int TOUR_DETAIL_ACTIVITY = 1001;
private SharedPreferences settings;
private OnSharedPreferenceChangeListener listener;
private List<Tour> tours;
boolean isMyTours;
ToursDataSource datasource;
ArrayAdapter<Tour> adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
/*
* ArrayAdapter<Tour> adapter = new TourListAdapter(this, tours);
* setListAdapter(adapter);
*/
final EditText editText = (EditText) findViewById(R.id.editTextSearch);
editText.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence cs, int arg1, int arg2,
int arg3) {
}
@Override
public void beforeTextChanged(CharSequence arg0, int arg1,
int arg2, int arg3) {
}
@Override
public void afterTextChanged(Editable arg0) {
MainActivity.this.adapter.getFilter().filter(arg0);
/*
* final Intent queryIntent = getIntent(); final String
* queryAction = queryIntent.getAction(); if
* (Intent.ACTION_SEARCH.equals(queryAction)) {
* doSearchQuery(queryIntent, "onNewIntent()"); } else { //
* mDeliveredByText
* .setText("onNewIntent(), but no ACTION_SEARCH intent"); }
*/
}
});
settings = PreferenceManager.getDefaultSharedPreferences(this);
listener = new OnSharedPreferenceChangeListener() {
@Override
public void onSharedPreferenceChanged(
SharedPreferences sharedPreferences, String key) {
MainActivity.this.refreshDisplay();
}
};
settings.registerOnSharedPreferenceChangeListener(listener);
datasource = new ToursDataSource(this);
datasource.open();
tours = datasource.findAll();
if (tours.size() == 0) {
createData();
tours = datasource.findAll();
}
isMyTours = false;
refreshDisplay();
}
public void refreshDisplay() {
boolean viewImages = settings.getBoolean(VIEWIMAGE, true);
if (viewImages) {
ArrayAdapter<Tour> adapter = new TourListAdapter(this, tours);
setListAdapter(adapter);
} else {
ArrayAdapter<Tour> adapter = new ArrayAdapter<Tour>(this,
android.R.layout.simple_list_item_1, tours);
setListAdapter(adapter);
}
}
@Override
protected void onResume() {
super.onResume();
datasource.open();
}
@Override
protected void onPause() {
super.onPause();
datasource.close();
}
private void createData() {
ToursPullParser parser = new ToursPullParser();
List<Tour> tours = parser.parseXML(this);
for (Tour tour : tours) {
datasource.create(tour);
}
}
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
super.onListItemClick(l, v, position, id);
Tour tour = tours.get(position);
Intent intent = new Intent(this, TourDetailActivity.class);
intent.putExtra(".model.Tour", tour);
intent.putExtra("isMyTours", isMyTours);
startActivityForResult(intent, TOUR_DETAIL_ACTIVITY);
}
/*
* @Override protected void onActivityResult(int requestCode, int
* resultCode, Intent data) { super.onActivityResult(requestCode,
* resultCode, data);
*
* if (requestCode == TOUR_DETAIL_ACTIVITY && resultCode == -1) {
* datasource.open(); tours = datasource.findMyTours(); refreshDisplay();
* isMyTours = true;
*
* } }
*/
/*
* private void doSearchQuery(final Intent queryIntent, final String
* entryPoint) {
*
* // The search query is provided as an "extra" string in the query intent
* final String queryString =
* queryIntent.getStringExtra(SearchManager.QUERY); //
* mQueryText.setText(queryString);
*
* // Record the query string in the recent queries suggestions provider. //
* SearchRecentSuggestions suggestions = new SearchRecentSuggestions(this,
* // SearchSuggestionSampleProvider.AUTHORITY,
* SearchSuggestionSampleProvider.MODE); //
* suggestions.saveRecentQuery(queryString, null); final Bundle appData =
* queryIntent.getBundleExtra(SearchManager.APP_DATA); if (appData == null)
* { // mAppDataText.setText("<no app data bundle>"); } if (appData != null)
* { String testStr = appData.getString("demo_key"); //
* mAppDataText.setText((testStr == null) ? "<no app data>" : testStr); }
*
* // mDeliveredByText.setText(entryPoint);
*
* }
*/
}
但它强行关闭!!!!
这是log cat：
08-04 07:10:51.045: E/AndroidRuntime(11234): FATAL EXCEPTION: main
08-04 07:10:51.045: E/AndroidRuntime(11234): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.search.xmlParse/com.search.xmlParsing.MainActivity2}: java.lang.NullPointerException
08-04 07:10:51.045: E/AndroidRuntime(11234): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1768)
08-04 07:10:51.045: E/AndroidRuntime(11234): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1784)
08-04 07:10:51.045: E/AndroidRuntime(11234): at android.app.ActivityThread.access$1500(ActivityThread.java:123)
08-04 07:10:51.045: E/AndroidRuntime(11234): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:939)
08-04 07:10:51.045: E/AndroidRuntime(11234): at android.os.Handler.dispatchMessage(Handler.java:99)
08-04 07:10:51.045: E/AndroidRuntime(11234): at android.os.Looper.loop(Looper.java:130)
08-04 07:10:51.045: E/AndroidRuntime(11234): at android.app.ActivityThread.main(ActivityThread.java:3835)
08-04 07:10:51.045: E/AndroidRuntime(11234): at java.lang.reflect.Method.invokeNative(Native Method)
08-04 07:10:51.045: E/AndroidRuntime(11234): at java.lang.reflect.Method.invoke(Method.java:507)
08-04 07:10:51.045: E/AndroidRuntime(11234): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:847)
08-04 07:10:51.045: E/AndroidRuntime(11234): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:605)
08-04 07:10:51.045: E/AndroidRuntime(11234): at dalvik.system.NativeStart.main(Native Method)
08-04 07:10:51.045: E/AndroidRuntime(11234): Caused by: java.lang.NullPointerException
08-04 07:10:51.045: E/AndroidRuntime(11234): at com.search.xmlParsing.MainActivity2.refreshDisplay(MainActivity2.java:63)
08-04 07:10:51.045: E/AndroidRuntime(11234): at com.search.xmlParsing.MainActivity2.onCreate(MainActivity2.java:58)
08-04 07:10:51.045: E/AndroidRuntime(11234): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
08-04 07:10:51.045: E/AndroidRuntime(11234): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1722)
08-04 07:10:51.045: E/AndroidRuntime(11234): ... 11 more
答案 0 :(得分：0)
我有另一种方法来搜索列表，我希望这对你有所帮助。
我看到了你的代码，我在两个类中进行了更改。在MainActivity我将ListActivity更改为Activity，代码为：
public class MainActivity2 extends Activity implements OnItemClickListener,
TextWatcher {
public static final String LOGTAG = "EXPLORECA";
public static final String USERNAME = "pref_username";
public static final String VIEWIMAGE = "pref_viewimages";
private static final int TOUR_DETAIL_ACTIVITY = 1001;
private SharedPreferences settings;
private OnSharedPreferenceChangeListener listener;
private List<Tour> tours;
boolean isMyTours;
ToursDataSource datasource;
private TourListAdapter2 mAdapter;
private ListView lviTours;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final EditText editText = (EditText) findViewById(R.id.editTextSearch);
lviTours = (ListView) findViewById(android.R.id.list);
lviTours.setOnItemClickListener(this);
editText.addTextChangedListener(this);
datasource = new ToursDataSource(this);
datasource.open();
settings = PreferenceManager.getDefaultSharedPreferences(this);
listener = new OnSharedPreferenceChangeListener() {
@Override
public void onSharedPreferenceChanged(
SharedPreferences sharedPreferences, String key) {
MainActivity.this.refreshDisplay();
}
};
settings.registerOnSharedPreferenceChangeListener(listener);
tours = datasource.findAll();
if (tours.size() == 0) {
createData();
tours = datasource.findAll();
}
isMyTours = false;
refreshDisplay();
}
public void refreshDisplay() {
boolean viewImages = settings.getBoolean(VIEWIMAGE, true);
if (viewImages) {
// ArrayAdapter<Tour> adapter = new TourListAdapter(this, tours);
// setListAdapter(adapter);
mAdapter = new TourListAdapter2(this, tours);
lviTours.setAdapter(mAdapter);
} else {
mAdapter = new TourListAdapter2(this, tours);
lviTours.setAdapter(mAdapter);
// ArrayAdapter<Tour> adapter = new ArrayAdapter<Tour>(this,
// android.R.layout.simple_list_item_1, tours);
// setListAdapter(adapter);
}
}
@Override
protected void onResume() {
super.onResume();
datasource.open();
}
@Override
protected void onPause() {
super.onPause();
datasource.close();
}
private void createData() {
ToursPullParser parser = new ToursPullParser();
List<Tour> tours = parser.parseXML(this);
for (Tour tour : tours) {
datasource.create(tour);
}
}
/*********** SEARCH ****************/
@Override
public void afterTextChanged(Editable arg0) {
}
@Override
public void beforeTextChanged(CharSequence arg0, int arg1, int arg2,
int arg3) {
}
@Override
public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) {
mAdapter.getFilter().filter(cs);
}
@Override
public void onItemClick(AdapterView<?> adapter, View view, int position,
long id) {
Tour tour = tours.get(position);
Intent intent = new Intent(this, TourDetailActivity.class);
intent.putExtra(".model.Tour", tour);
intent.putExtra("isMyTours", isMyTours);
startActivityForResult(intent, TOUR_DETAIL_ACTIVITY);
}
}
我创建了另一个类TourListAdapter2 扩展 BaseAdapter和实现 Filterable来搜索列表。代码是：
公共类TourListAdapter2扩展BaseAdapter实现Filterable {
private LayoutInflater mInflater;
List<Tour> mList;
List<Tour> mFilter;
List<Tour> tours;
private Context mContext;
public TourListAdapter2(Context context, List<Tour> tours) {
mContext = context;
mInflater = LayoutInflater.from(context);
mList = tours;
mFilter = tours;
}
@Override
public int getCount() {
return mFilter.size();
}
@Override
public Object getItem(int position) {
return mFilter.get(position);
}
@Override
public long getItemId(int position) {
return mFilter.get(position).getId();
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder;
Tour tour = (Tour) getItem(position);
if (convertView == null) {
convertView = mInflater.inflate(R.layout.listitem, null);
viewHolder = new ViewHolder();
viewHolder.tviName = (TextView) convertView
.findViewById(R.id.titleText);
viewHolder.iviImage = (ImageView) convertView
.findViewById(R.id.imageView1);
convertView.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
viewHolder.tviName.setText(tour.getTitle());
int imageResource = mContext.getResources().getIdentifier(
tour.getImage(), "drawable", mContext.getPackageName());
if (imageResource != 0) {
viewHolder.iviImage.setImageResource(imageResource);
}
return convertView;
}
class ViewHolder {
public TextView tviName;
public ImageView iviImage;
}
/*********** SEARCH **********/
@Override
public Filter getFilter() {
return new Filter() {
@SuppressWarnings("unchecked")
@Override
protected void publishResults(CharSequence constraint,
FilterResults results) {
mFilter = (List<Tour>) results.values;
notifyDataSetChanged();
}
@Override
protected FilterResults performFiltering(CharSequence charSequence) {
FilterResults results = new FilterResults();
if (charSequence == null || charSequence.length() == 0) {
results.values = mList;
results.count = mList.size();
} else {
ArrayList<Tour> filterResultsData = new ArrayList<Tour>();
for (Tour data : mList) {
if (data.getTitle().contains(charSequence)) {
filterResultsData.add(data);
}
}
results.values = filterResultsData;
results.count = filterResultsData.size();
}
return results;
}
};
}
}
答案 1 :(得分：0)
确保有一个带有id = editTextSearch
的EditText的xml文件 <EditText
android:id="@+id/editTextSearch"
...
/>