搜索 xml 解析

Question

我是安卓新手。 我有一个试图使用 Java 搜索的 XML 文件。 （问题出在编辑文本中）。

my code need edit

如何进行从编辑文本中获取文本并在列表视图中过滤结果的搜索？ 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);
 * 
 * }
 */
}

但它强制关闭!!!!

这是日志猫：

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

Answer 1

我有另一种搜索列表的方法，希望对您有所帮助。

我看到了您的代码，并在两个类中进行了更改。在MainActivity 中，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，它扩展 BaseAdapter 和实现 Filterable 以在列表中搜索。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;
        }
    };
}

}

Answer 2

确保有一个带有 id=editTextSearch 的 EditText 的 xml 文件

    <EditText
        android:id="@+id/editTextSearch"
        ...
    />