Benutzerdefinierte Filterung in Android mithilfe von ArrayAdapter

Ich versuche, meine ListView zu filtern, die mit diesem ArrayAdapter gefüllt ist:

package me.alxandr.android.mymir.adapters; import java.util.ArrayList; import java.util.Collection; import java.util.Collections; import java.util.HashMap; import java.util.Iterator; import java.util.Set; import me.alxandr.android.mymir.R; import me.alxandr.android.mymir.model.Manga; import android.content.Context; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.ArrayAdapter; import android.widget.Filter; import android.widget.SectionIndexer; import android.widget.TextView; public class MangaListAdapter extends ArrayAdapter implements SectionIndexer { public ArrayList items; public ArrayList filtered; private Context context; private HashMap alphaIndexer; private String[] sections = new String[0]; private Filter filter; private boolean enableSections; public MangaListAdapter(Context context, int textViewResourceId, ArrayList items, boolean enableSections) { super(context, textViewResourceId, items); this.filtered = items; this.items = filtered; this.context = context; this.filter = new MangaNameFilter(); this.enableSections = enableSections; if(enableSections) { alphaIndexer = new HashMap(); for(int i = items.size() - 1; i >= 0; i--) { Manga element = items.get(i); String firstChar = element.getName().substring(0, 1).toUpperCase(); if(firstChar.charAt(0) > 'Z' || firstChar.charAt(0) < 'A') firstChar = "@"; alphaIndexer.put(firstChar, i); } Set keys = alphaIndexer.keySet(); Iterator it = keys.iterator(); ArrayList keyList = new ArrayList(); while(it.hasNext()) keyList.add(it.next()); Collections.sort(keyList); sections = new String[keyList.size()]; keyList.toArray(sections); } } @Override public View getView(int position, View convertView, ViewGroup parent) { View v = convertView; if(v == null) { LayoutInflater vi = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); v = vi.inflate(R.layout.mangarow, null); } Manga o = items.get(position); if(o != null) { TextView tt = (TextView) v.findViewById(R.id.MangaRow_MangaName); TextView bt = (TextView) v.findViewById(R.id.MangaRow_MangaExtra); if(tt != null) tt.setText(o.getName()); if(bt != null) bt.setText(o.getLastUpdated() + " - " + o.getLatestChapter()); if(enableSections && getSectionForPosition(position) != getSectionForPosition(position + 1)) { TextView h = (TextView) v.findViewById(R.id.MangaRow_Header); h.setText(sections[getSectionForPosition(position)]); h.setVisibility(View.VISIBLE); } else { TextView h = (TextView) v.findViewById(R.id.MangaRow_Header); h.setVisibility(View.GONE); } } return v; } @Override public void notifyDataSetInvalidated() { if(enableSections) { for (int i = items.size() - 1; i >= 0; i--) { Manga element = items.get(i); String firstChar = element.getName().substring(0, 1).toUpperCase(); if(firstChar.charAt(0) > 'Z' || firstChar.charAt(0) < 'A') firstChar = "@"; alphaIndexer.put(firstChar, i); } Set keys = alphaIndexer.keySet(); Iterator it = keys.iterator(); ArrayList keyList = new ArrayList(); while (it.hasNext()) { keyList.add(it.next()); } Collections.sort(keyList); sections = new String[keyList.size()]; keyList.toArray(sections); super.notifyDataSetInvalidated(); } } public int getPositionForSection(int section) { if(!enableSections) return 0; String letter = sections[section]; return alphaIndexer.get(letter); } public int getSectionForPosition(int position) { if(!enableSections) return 0; int prevIndex = 0; for(int i = 0; i  position && prevIndex  0) { ArrayList filt = new ArrayList(); ArrayList lItems = new ArrayList(); synchronized (items) { Collections.copy(lItems, items); } for(int i = 0, l = lItems.size(); i < l; i++) { Manga m = lItems.get(i); if(m.getName().toLowerCase().contains(constraint)) filt.add(m); } result.count = filt.size(); result.values = filt; } else { synchronized(items) { result.values = items; result.count = items.size(); } } return result; } @SuppressWarnings("unchecked") @Override protected void publishResults(CharSequence constraint, FilterResults results) { // NOTE: this function is *always* called from the UI thread. filtered = (ArrayList)results.values; notifyDataSetChanged(); } } } 

Wenn ich filter (‘test’) auf dem Filter anrufe, passiert jedoch nichts (oder der Hintergrund-Thread wird ausgeführt, aber die Liste wird nicht gefiltert, so weit der Benutzer es merkt). Wie kann ich das beheben?

   

Das hat mein Problem behoben. Ich bin mir nicht sicher, ob es die beste Lösung ist, aber es funktioniert. Die Open-Source-Version meines Projekts, also können Sie den Code hier verwenden, sollte er sich als nützlich erweisen :-).

 package me.alxandr.android.mymir.adapters; import java.util.ArrayList; import java.util.Collection; import java.util.Collections; import java.util.HashMap; import java.util.Iterator; import java.util.Set; import me.alxandr.android.mymir.R; import me.alxandr.android.mymir.model.Manga; import android.content.Context; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.ArrayAdapter; import android.widget.Filter; import android.widget.SectionIndexer; import android.widget.TextView; public class MangaListAdapter extends ArrayAdapter implements SectionIndexer { public ArrayList items; public ArrayList filtered; private Context context; private HashMap alphaIndexer; private String[] sections = new String[0]; private Filter filter; private boolean enableSections; public Manga getByPosition(int position) { return items.get(position); } public MangaListAdapter(Context context, int textViewResourceId, ArrayList items, boolean enableSections) { super(context, textViewResourceId, items); this.filtered = items; this.items = ArrayList items.clone(); this.context = context; this.filter = new MangaNameFilter(); this.enableSections = enableSections; if(enableSections) { alphaIndexer = new HashMap(); for(int i = items.size() - 1; i >= 0; i--) { Manga element = items.get(i); String firstChar = element.getName().substring(0, 1).toUpperCase(); if(firstChar.charAt(0) > 'Z' || firstChar.charAt(0) < 'A') firstChar = "@"; alphaIndexer.put(firstChar, i); } Set keys = alphaIndexer.keySet(); Iterator it = keys.iterator(); ArrayList keyList = new ArrayList(); while(it.hasNext()) keyList.add(it.next()); Collections.sort(keyList); sections = new String[keyList.size()]; keyList.toArray(sections); } } @Override public View getView(int position, View convertView, ViewGroup parent) { View v = convertView; if(v == null) { LayoutInflater vi = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); v = vi.inflate(R.layout.mangarow, null); } Manga o = filtered.get(position); if(o != null) { TextView tt = (TextView) v.findViewById(R.id.MangaRow_MangaName); TextView bt = (TextView) v.findViewById(R.id.MangaRow_MangaExtra); if(tt != null) tt.setText(o.getName()); if(bt != null) bt.setText(o.getLastUpdated() + " - " + o.getLatestChapter()); if(enableSections && getSectionForPosition(position) != getSectionForPosition(position + 1)) { TextView h = (TextView) v.findViewById(R.id.MangaRow_Header); h.setText(sections[getSectionForPosition(position)]); h.setVisibility(View.VISIBLE); } else { TextView h = (TextView) v.findViewById(R.id.MangaRow_Header); h.setVisibility(View.GONE); } } return v; } @Override public void notifyDataSetInvalidated() { if(enableSections) { for (int i = items.size() - 1; i >= 0; i--) { Manga element = items.get(i); String firstChar = element.getName().substring(0, 1).toUpperCase(); if(firstChar.charAt(0) > 'Z' || firstChar.charAt(0) < 'A') firstChar = "@"; alphaIndexer.put(firstChar, i); } Set keys = alphaIndexer.keySet(); Iterator it = keys.iterator(); ArrayList keyList = new ArrayList(); while (it.hasNext()) { keyList.add(it.next()); } Collections.sort(keyList); sections = new String[keyList.size()]; keyList.toArray(sections); super.notifyDataSetInvalidated(); } } public int getPositionForSection(int section) { if(!enableSections) return 0; String letter = sections[section]; return alphaIndexer.get(letter); } public int getSectionForPosition(int position) { if(!enableSections) return 0; int prevIndex = 0; for(int i = 0; i < sections.length; i++) { if(getPositionForSection(i) > position && prevIndex < = position) { prevIndex = i; break; } prevIndex = i; } return prevIndex; } public Object[] getSections() { return sections; } @Override public Filter getFilter() { if(filter == null) filter = new MangaNameFilter(); return filter; } private class MangaNameFilter extends Filter { @Override protected FilterResults performFiltering(CharSequence constraint) { // NOTE: this function is *always* called from a background thread, and // not the UI thread. constraint = constraint.toString().toLowerCase(); FilterResults result = new FilterResults(); if(constraint != null && constraint.toString().length() > 0) { ArrayList filt = new ArrayList(); ArrayList lItems = new ArrayList(); synchronized (this) { lItems.addAll(items); } for(int i = 0, l = lItems.size(); i < l; i++) { Manga m = lItems.get(i); if(m.getName().toLowerCase().contains(constraint)) filt.add(m); } result.count = filt.size(); result.values = filt; } else { synchronized(this) { result.values = items; result.count = items.size(); } } return result; } @SuppressWarnings("unchecked") @Override protected void publishResults(CharSequence constraint, FilterResults results) { // NOTE: this function is *always* called from the UI thread. filtered = (ArrayList)results.values; notifyDataSetChanged(); clear(); for(int i = 0, l = filtered.size(); i < l; i++) add(filtered.get(i)); notifyDataSetInvalidated(); } } } 

Ich hatte nicht das Bedürfnis, irgendetwas von dem oben Gesagten zu tun. Override toString () Methode von POJO like …

 public String toString() { return this.getCallTitle() == null ? "" : this.getCallTitle().toLowerCase(); } 

TextWatcher filtert einfach und einfacher.

 adapter.getFilter().filter(chars.toString().toLowerCase()); 

Sofern Sie keine sehr benutzerdefinierte Filterung haben, funktioniert diese Lösung. Hoffe, dass dies anderen nützt.

Ich habe diese class geschrieben, die im Grunde eine Kopie von ArrayAdapter mit nur einer leichten Modifikation, ähnlich der Alxandr-Lösung, aber eleganter.

Alles, was ich tat, war, die ArrayAdapter.ArrayFilter von der verschachtelten class ArrayAdapter.ArrayFilter in die ArrayAdapter -class zu ziehen, um sie freizulegen (und dem Benutzer zu erlauben, sie zu überschreiben).

 package com.example; /* Copyright (C) 2006 The Android Open Source Project Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. You may obtain a copy of the License at * http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, * either express or implied. See the License for the specific language governing permissions and limitations under the * License. */ import java.util.ArrayList; import java.util.Arrays; import java.util.Collection; import java.util.Collections; import java.util.Comparator; import java.util.List; import android.content.Context; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.ArrayAdapter; import android.widget.BaseAdapter; import android.widget.Filter; import android.widget.Filterable; import android.widget.TextView; /** * Slightly adopted ArrayAdapter. Basically a simple copy of ArrayAdapter with an extracted method filterObject() to * allow easy change of the filtering-behaviour. * * A concrete BaseAdapter that is backed by an array of arbitrary objects. By default this class expects that the * provided resource id references a single TextView. If you want to use a more complex layout, use the constructors * that also takes a field id. That field id should reference a TextView in the larger layout resource. * * 

* However the TextView is referenced, it will be filled with the toString() of each object in the array. You can add * lists or arrays of custom objects. Override the toString() method of your objects to determine what text will be * displayed for the item in the list. * *

* To use something other than TextViews for the array display, for instance, ImageViews, or to have some of data * besides toString() results fill the views, override {@link #getView(int, View, ViewGroup)} to return the type of view * you want. * * @param The class, this adapter should hold */ public class OGArrayAdapter extends BaseAdapter implements Filterable { /** * Contains the list of objects that represent the data of this ArrayAdapter. The content of this list is referred * to as "the array" in the documentation. */ private List mObjects; /** * 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 mLock = new Object(); /** * The resource indicating what views to inflate to display the content of this array adapter. */ private int mResource; /** * The resource indicating what views to inflate to display the content of this array adapter in a drop down widget. */ private int mDropDownResource; /** * If the inflated resource is not a TextView, {@link #mFieldId} is used to find a TextView inside the inflated * views hierarchy. This field must contain the identifier that matches the one defined in the resource file. */ private int mFieldId = 0; /** * Indicates whether or not {@link #notifyDataSetChanged()} must be called whenever {@link #mObjects} is modified. */ private boolean mNotifyOnChange = true; private Context mContext; // A copy of the original mObjects array, initialized from and then used instead as soon as // the mFilter ArrayFilter is used. mObjects will then only contain the filtered values. private ArrayList mOriginalValues; private OGArrayFilter mFilter; private LayoutInflater mInflater; /** * Constructor * * @param context The current context. * @param textViewResourceId The resource ID for a layout file containing a TextView to use when instantiating * views. */ public OGArrayAdapter(Context context, int textViewResourceId) { init(context, textViewResourceId, 0, new ArrayList()); } /** * Constructor * * @param context The current context. * @param resource The resource ID for a layout file containing a layout to use when instantiating views. * @param textViewResourceId The id of the TextView within the layout resource to be populated */ public OGArrayAdapter(Context context, int resource, int textViewResourceId) { init(context, resource, textViewResourceId, new ArrayList()); } /** * Constructor * * @param context The current context. * @param textViewResourceId The resource ID for a layout file containing a TextView to use when instantiating * views. * @param objects The objects to represent in the ListView. */ public OGArrayAdapter(Context context, int textViewResourceId, T[] objects) { init(context, textViewResourceId, 0, Arrays.asList(objects)); } /** * Constructor * * @param context The current context. * @param resource The resource ID for a layout file containing a layout to use when instantiating views. * @param textViewResourceId The id of the TextView within the layout resource to be populated * @param objects The objects to represent in the ListView. */ public OGArrayAdapter(Context context, int resource, int textViewResourceId, T[] objects) { init(context, resource, textViewResourceId, Arrays.asList(objects)); } /** * Constructor * * @param context The current context. * @param textViewResourceId The resource ID for a layout file containing a TextView to use when instantiating * views. * @param objects The objects to represent in the ListView. */ public OGArrayAdapter(Context context, int textViewResourceId, List objects) { init(context, textViewResourceId, 0, objects); } /** * Constructor * * @param context The current context. * @param resource The resource ID for a layout file containing a layout to use when instantiating views. * @param textViewResourceId The id of the TextView within the layout resource to be populated * @param objects The objects to represent in the ListView. */ public OGArrayAdapter(Context context, int resource, int textViewResourceId, List objects) { init(context, resource, textViewResourceId, objects); } /** * Adds the specified object at the end of the array. * * @param object The object to add at the end of the array. */ public void add(T object) { synchronized (mLock) { if (mOriginalValues != null) { mOriginalValues.add(object); } else { mObjects.add(object); } } if (mNotifyOnChange) notifyDataSetChanged(); } /** * Adds the specified Collection at the end of the array. * * @param collection The Collection to add at the end of the array. */ public void addAll(Collection< ? extends T> collection) { synchronized (mLock) { if (mOriginalValues != null) { mOriginalValues.addAll(collection); } else { mObjects.addAll(collection); } } if (mNotifyOnChange) notifyDataSetChanged(); } /** * Adds the specified items at the end of the array. * * @param items The items to add at the end of the array. */ public void addAll(T... items) { synchronized (mLock) { if (mOriginalValues != null) { Collections.addAll(mOriginalValues, items); } else { Collections.addAll(mObjects, items); } } if (mNotifyOnChange) notifyDataSetChanged(); } /** * Inserts the specified object at the specified index in the array. * * @param object The object to insert into the array. * @param index The index at which the object must be inserted. */ public void insert(T object, int index) { synchronized (mLock) { if (mOriginalValues != null) { mOriginalValues.add(index, object); } else { mObjects.add(index, object); } } if (mNotifyOnChange) notifyDataSetChanged(); } /** * Removes the specified object from the array. * * @param object The object to remove. */ public void remove(T object) { synchronized (mLock) { if (mOriginalValues != null) { mOriginalValues.remove(object); } else { mObjects.remove(object); } } if (mNotifyOnChange) notifyDataSetChanged(); } /** * Remove all elements from the list. */ public void clear() { synchronized (mLock) { if (mOriginalValues != null) { mOriginalValues.clear(); } else { mObjects.clear(); } } if (mNotifyOnChange) notifyDataSetChanged(); } /** * Sorts the content of this adapter using the specified comparator. * * @param comparator The comparator used to sort the objects contained in this adapter. */ public void sort(Comparator< ? super T> comparator) { synchronized (mLock) { if (mOriginalValues != null) { Collections.sort(mOriginalValues, comparator); } else { Collections.sort(mObjects, comparator); } } if (mNotifyOnChange) notifyDataSetChanged(); } /** * {@inheritDoc} */ @Override public void notifyDataSetChanged() { super.notifyDataSetChanged(); mNotifyOnChange = true; } /** * Control whether methods that change the list ({@link #add}, {@link #insert}, {@link #remove}, {@link #clear}) * automatically call {@link #notifyDataSetChanged}. If set to false, caller must manually call * notifyDataSetChanged() to have the changes reflected in the attached view. * * The default is true, and calling notifyDataSetChanged() resets the flag to true. * * @param notifyOnChange if true, modifications to the list will automatically call {@link #notifyDataSetChanged} */ public void setNotifyOnChange(boolean notifyOnChange) { mNotifyOnChange = notifyOnChange; } private void init(Context context, int resource, int textViewResourceId, List objects) { mContext = context; mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); mResource = mDropDownResource = resource; mObjects = objects; mFieldId = textViewResourceId; } /** * Returns the context associated with this array adapter. The context is used to create views from the resource * passed to the constructor. * * @return The Context associated with this adapter. */ public Context getContext() { return mContext; } /** * {@inheritDoc} */ public int getCount() { return mObjects.size(); } /** * {@inheritDoc} */ public T getItem(int position) { return mObjects.get(position); } /** * Returns the position of the specified item in the array. * * @param item The item to retrieve the position of. * * @return The position of the specified item. */ public int getPosition(T item) { return mObjects.indexOf(item); } /** * {@inheritDoc} */ public long getItemId(int position) { return position; } /** * {@inheritDoc} */ public View getView(int position, View convertView, ViewGroup parent) { return createViewFromResource(position, convertView, parent, mResource); } private View createViewFromResource(int position, View convertView, ViewGroup parent, int resource) { View view; TextView text; if (convertView == null) { view = mInflater.inflate(resource, parent, false); } else { view = convertView; } try { if (mFieldId == 0) { // If no custom field is assigned, assume the whole resource is a TextView text = (TextView) view; } else { // Otherwise, find the TextView field within the layout text = (TextView) view.findViewById(mFieldId); } } catch (ClassCastException e) { Log.e("ArrayAdapter", "You must supply a resource ID for a TextView"); throw new IllegalStateException("ArrayAdapter requires the resource ID to be a TextView", e); } T item = getItem(position); if (item instanceof CharSequence) { text.setText((CharSequence) item); } else { text.setText(item.toString()); } return view; } /** *

* Sets the layout resource to create the drop down views. *

* * @param resource the layout resource defining the drop down views * @see #getDropDownView(int, android.view.View, android.view.ViewGroup) */ public void setDropDownViewResource(int resource) { this.mDropDownResource = resource; } /** * {@inheritDoc} */ @Override public View getDropDownView(int position, View convertView, ViewGroup parent) { return createViewFromResource(position, convertView, parent, mDropDownResource); } /** * Creates a new ArrayAdapter from external resources. The content of the array is obtained through * {@link android.content.res.Resources#getTextArray(int)}. * * @param context The application's environment. * @param textArrayResId The identifier of the array to use as the data source. * @param textViewResId The identifier of the layout used to create views. * * @return An ArrayAdapter. */ public static ArrayAdapter createFromResource(Context context, int textArrayResId, int textViewResId) { CharSequence[] strings = context.getResources().getTextArray(textArrayResId); return new ArrayAdapter(context, textViewResId, strings); } /** * {@inheritDoc} */ public Filter getFilter() { if (mFilter == null) { mFilter = new OGArrayFilter(); } return mFilter; } /** * Performs filtering on the provided object and returns true, if the object should be in the filtered collection, * or false if it shouldn't. * * @param myObject The object to be inspected * @param constraint Constraint, that the object has to fulfil * @return true, if the object should be in the filteredResult, false otherwise */ protected boolean filterObject(T myObject, String constraint) { final String valueText = myObject.toString().toLowerCase(); // First match against the whole, non-splitted value if (valueText.startsWith(constraint)) { return true; } else { final String[] words = valueText.split(" "); final int wordCount = words.length; // Start at index 0, in case valueText starts with space(s) for (int k = 0; k < wordCount; k++) { if (words[k].startsWith(constraint)) { return true; } } } // No match, so don't add to collection return false; } /** *

* An array filter constrains the content of the array adapter with a prefix. Each item that does not start with the * supplied prefix is removed from the list. *

*/ private class OGArrayFilter extends Filter { @Override protected FilterResults performFiltering(CharSequence prefix) { FilterResults results = new FilterResults(); if (mOriginalValues == null) { synchronized (mLock) { mOriginalValues = new ArrayList(mObjects); } } if (prefix == null || prefix.length() == 0) { ArrayList list; synchronized (mLock) { list = new ArrayList(mOriginalValues); } results.values = list; results.count = list.size(); } else { String prefixString = prefix.toString().toLowerCase(); ArrayList values; synchronized (mLock) { values = new ArrayList(mOriginalValues); } final int count = values.size(); final ArrayList newValues = new ArrayList(); for (int i = 0; i < count; i++) { final T value = values.get(i); if (filterObject(value, prefixString)) { newValues.add(value); } } results.values = newValues; results.count = newValues.size(); } return results; } @Override protected void publishResults(CharSequence constraint, FilterResults results) { //noinspection unchecked mObjects = (List) results.values; if (results.count > 0) { notifyDataSetChanged(); } else { notifyDataSetInvalidated(); } } } }

Der Vorteil dieser Lösung ist ihre Schönheit bei der Anwendung, einfach durch Überschreiben der filterObject-Methode, die aus der ArrayAdapter.ArrayFilter-class in den ArrayAdapter gezogen wurde:

 public class MyAdapter extends OGArrayAdapter { // Do the rest of your adapter @Override protected boolean filterObject(OGScene myObject, String constraint) { // If true, the object will be in the list, if false, it will be filtered. // Do your own filtering with myObject as you desire return myObject.fulfillsConstraint(constraint); } } 

Der beste Weg, um ArrayAdapter zu filtern, ist, eine eigene Filterklasse zu erstellen:

 private class MyFilter extends Filter 

Erstellen Sie dann in dieser function das neue Objekt-Array, das nach dem Filter angezeigt werden soll (Sie finden eine gute Implementierung im Quellcode der class ArrayAdapter )

 @Override protected FilterResults performFiltering(CharSequence prefix) 

jetzt ist der Trick in dieser Methode

 @Override protected void publishResults(CharSequence constraint, FilterResults results) 

Wenn Sie den Array-Adapter verwenden, können Sie dies nicht tun:

 myAdapterData = results.values 

Da Sie dann Ihre Daten von den Super-Daten trennen, müssen Sie dies tun, um Ihre Referenz auf den Super-Original-Daten-Array zu behalten:

 data.clear(); data.addAll((List) results.values); 

und dann überschreiben

getFilter ()

in Ihrem Adapter, zum Beispiel:

 @Override public Filter getFilter() { if (filter == null) { filter = new MyFilter(); } return filter; }