Android 如何使用ArrayAdapter为ListView编写自定义筛选器

我有一个ListView，它连接到ArrayAdapter，其中Artist是我的一个简单类，它只有一个id和一个名称

现在我想筛选ListView，因此我调用：

artistAdapter.getFilter().filter("bla", new Filter.FilterListener() {
    public void onFilterComplete(int count) {
        Log.d(Config.LOG_TAG, "filter complete! count: " + count); // returns 8
        Log.d(Config.LOG_TAG, "adapter count: " + artistAdapter.getCount()); // return 1150
    }
});

第一条debug语句打印8的计数。这是以“bla”开头的listitems的正确计数，但适配器没有得到它。第二条debug语句打印1150个项目。这是列表中项目的完整数量

因此，过滤器不会告诉适配器它已经过滤了底层数据

---

我现在想知道：我是否在适配器中编写了一些代码，以便它从过滤器中获取更新？我必须编写自定义筛选器吗？我该怎么办？

我想你可以使用

notifyDataSetChanged（）。
实际上

我注意到我应该在performFiltering中使用“originalItems”列表来构建新的过滤列表

这将修复您看到的有关更改过滤器中文本的任何问题。例如，你搜索“面包”，然后退格到只有一个“B”，你应该看到所有的“B”。在我原来的帖子里，你不会有

    private class GlycaemicIndexItemAdapter extends ArrayAdapter<GlycaemicIndexItem> {

    private ArrayList<GlycaemicIndexItem> items;
    private ArrayList<GlycaemicIndexItem> originalItems = new ArrayList<GlycaemicIndexItem>();
    private GlycaemicIndexItemFilter filter;
    private final Object mLock = new Object();

    public GlycaemicIndexItemAdapter(Context context, int textViewResourceId, ArrayList<GlycaemicIndexItem> newItems) {
            super(context, textViewResourceId, newItems);
            this.items = newItems;
            cloneItems(newItems);
    }

    protected void cloneItems(ArrayList<GlycaemicIndexItem> items) {
        for (Iterator iterator = items.iterator(); iterator
        .hasNext();) {
            GlycaemicIndexItem gi = (GlycaemicIndexItem) iterator.next();
            originalItems.add(gi);
        }
    }

    @Override
    public int getCount() {
        synchronized(mLock) {
            return items!=null ? items.size() : 0;  

    }

    @Override
    public GlycaemicIndexItem getItem(int item) {
        GlycaemicIndexItem gi = null;
        synchronized(mLock) {
                gi = items!=null ? items.get(item) : null;

        }
        return gi;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
            View v = convertView;
            if (v == null) {
                LayoutInflater vi = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                v = vi.inflate(R.layout.row, null);
            }

            GlycaemicIndexItem i  = null;
            synchronized(mLock) {
                i = items.get(position);
            }

            if (i != null) {
                    TextView tt = (TextView) v.findViewById(R.id.rowText);
                    TextView bt = (TextView) v.findViewById(R.id.rowText2);
                    if (tt != null) {
                          tt.setText("Name: "+i.getName());                            
                    }
                    if(bt != null){
                          bt.setText("GI Value: " + i.getGlycaemicIndex());
                    }
            }
            return v;
    }
    /**
     * Implementing the Filterable interface.
     */
    public Filter getFilter() {
        if (filter == null) {
            filter = new GlycaemicIndexItemFilter();
        }
        return filter;
    }   

    /**
     * Custom Filter implementation for the items adapter.
     *
     */
    private class GlycaemicIndexItemFilter extends Filter {
        protected FilterResults performFiltering(CharSequence prefix) {
            // Initiate our results object
            FilterResults results = new FilterResults();

            // No prefix is sent to filter by so we're going to send back the original array
            if (prefix == null || prefix.length() == 0) {
                synchronized (mLock) {
                    results.values = originalItems;
                    results.count = originalItems.size();
                }
            } else {
                synchronized(mLock) {
                        // Compare lower case strings
                    String prefixString = prefix.toString().toLowerCase();
                    final ArrayList<GlycaemicIndexItem> filteredItems = new ArrayList<GlycaemicIndexItem>();
                    // Local to here so we're not changing actual array
                    final ArrayList<GlycaemicIndexItem> localItems = new ArrayList<GlycaemicIndexItem>();
                    localItems.addAll(originalItems);
                    final int count = localItems.size();

                    for (int i = 0; i < count; i++) {
                        final GlycaemicIndexItem item = localItems.get(i);
                        final String itemName = item.getName().toString().toLowerCase();

                        // First match against the whole, non-splitted value
                        if (itemName.startsWith(prefixString)) {
                            filteredItems.add(item);
                        } else {} /* This is option and taken from the source of ArrayAdapter
                            final String[] words = itemName.split(" ");
                            final int wordCount = words.length;

                            for (int k = 0; k < wordCount; k++) {
                                if (words[k].startsWith(prefixString)) {
                                    newItems.add(item);
                                    break;
                                }
                            }
                        } */
                    }

                    // Set and return
                    results.values = filteredItems;
                    results.count = filteredItems.size();
                }//end synchronized
            }

            return results;
        }

        @SuppressWarnings("unchecked")
        @Override
        protected void publishResults(CharSequence prefix, FilterResults results) {
            //noinspection unchecked
            synchronized(mLock) {
                final ArrayList<GlycaemicIndexItem> localItems = (ArrayList<GlycaemicIndexItem>) results.values;
                notifyDataSetChanged();
                clear();
                //Add the items back in
                for (Iterator iterator = localItems.iterator(); iterator
                        .hasNext();) {
                    GlycaemicIndexItem gi = (GlycaemicIndexItem) iterator.next();
                    add(gi);
                }
            }//end synchronized
        }
    }
}

private class GlycaemicIndexItemAdapter扩展了ArrayAdapter{
私有ArrayList项；
private ArrayList originalItems=new ArrayList（）；
私有血糖指数过滤器；
私有最终对象mLock=新对象（）；
public GlycaemicIndexItemAdapter（上下文、int-textViewResourceId、ArrayList-newItems）{
super（上下文、textViewResourceId、newItems）；
this.items=newItems；
克隆门（新项）；
}
受保护的空克隆项（ArrayList项）{
for（迭代器迭代器=items.Iterator（）；迭代器
.hasNext（）；）{
GlycaemicIndexItem gi=（GlycaemicIndexItem）迭代器.next（）；
添加（gi）；
}
}
@凌驾
public int getCount（）{
已同步（mLock）{
返回项！=null？项。大小（）：0；
}
@凌驾
公共血糖指数getItem（int项）{
血糖指数gi=null；
已同步（mLock）{
gi=items！=null？items.get（item）：null；
}
返回gi；
}
@凌驾
公共视图getView（int位置、视图转换视图、视图组父视图）{
视图v=转换视图；
如果（v==null）{
LayoutInflater vi=（LayoutInflater）getSystemService（Context.LAYOUT\u INFLATER\u SERVICE）；
v=vi.充气（R.布局.行，空）；
}
血糖指数i=null；
已同步（mLock）{
i=项目。获取（位置）；
}
如果（i！=null）{
TextView tt=（TextView）v.findViewById（R.id.rowText）；
TextView bt=（TextView）v.findViewById（R.id.rowText2）；
如果（tt！=null）{
tt.setText（“Name:+i.getName（））；
}
如果（bt！=null）{
bt.setText（“GI值：+i.getGlycaemicIndex（））；
}
}
返回v；
}
/**
*实现可过滤接口。
*/
公共过滤器getFilter（）{
if（filter==null）{
filter=新的血糖指数xitemfilter（）；
}
回流过滤器；
}   
/**
*items适配器的自定义筛选器实现。
*
*/
私有类GlycaemicIndexItemFilter扩展了筛选器{
受保护的筛选器结果执行筛选（字符序列前缀）{
//启动我们的结果对象
FilterResults results=新的FilterResults（）；
//没有前缀发送到筛选依据，因此我们将发送回原始数组
if（prefix==null | | prefix.length（）==0）{
已同步（mLock）{
结果。值=原始值；
results.count=originalItems.size（）；
}
}否则{
已同步（mLock）{
//比较小写字符串
字符串prefixString=prefix.toString（）.toLowerCase（）；
final ArrayList filteredItems=新的ArrayList（）；
//本地到这里，所以我们不改变实际数组
final ArrayList localItems=新的ArrayList（）；
localItems.addAll（originalItems）；
最终整数计数=localItems.size（）；
for（int i=0；i   package com.tilleytech.android.myhealthylife;

     import java.util.ArrayList;
     import java.util.Iterator;

     import android.app.ListActivity;
      import android.content.Context;
     import android.content.res.Resources;
     import android.os.Bundle;
     import android.text.Editable;
      import android.text.TextWatcher;
      import android.view.LayoutInflater;
        import android.view.View;
       import android.view.ViewGroup;
       import android.widget.ArrayAdapter;
       import android.widget.EditText;
       import android.widget.Filter;
       import android.widget.ListView;
       import android.widget.TextView;


        public class GlycaemicIndexAtoZActivity extends ListActivity {
          /** Called when the activity is first created. */
        private GlycaemicIndexItemAdapter giAdapter; 
        private TextWatcher filterTextWatcher;
        private EditText filterText = null;

        @Override
        public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.giatoz);            

        ListView lv = getListView();
        lv.setTextFilterEnabled(true);
        // By using setAdapter method in listview we an add string array in list.
        ArrayList<GlycaemicIndexItem> list = getListItems();

        giAdapter = new GlycaemicIndexItemAdapter(this, R.layout.row, list);
        giAdapter.notifyDataSetChanged();
        setListAdapter(giAdapter);

        filterText = (EditText)findViewById(R.id.GI_AtoZSearchEditText);
        filterTextWatcher = new TextWatcher() {

            public void afterTextChanged(Editable s) {
                giAdapter.getFilter().filter(s); //Filter from my adapter
                giAdapter.notifyDataSetChanged(); //Update my view

            }

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

            public void onTextChanged(CharSequence s, int start, int before,
                    int count) {

            }

        };
        filterText.addTextChangedListener(filterTextWatcher);
    }

    private ArrayList<GlycaemicIndexItem> getListItems() {
        ArrayList<GlycaemicIndexItem> result = new ArrayList<GlycaemicIndexItem>();

        Resources res = getResources();
        //Get our raw strings
        String[] array = res.getStringArray(R.array.GIList);
        for (int i = 0; i < array.length; i++) {
            GlycaemicIndexItem gi = new GlycaemicIndexItem();
            gi.setName(array[i]);
            gi.setGlycaemicIndex(1);
            result.add(gi);
        }

        return result;
    }

    private class GlycaemicIndexItemAdapter extends ArrayAdapter<GlycaemicIndexItem> {

        private ArrayList<GlycaemicIndexItem> items;
        private ArrayList<GlycaemicIndexItem> originalItems = new ArrayList<GlycaemicIndexItem>();
        private GlycaemicIndexItemFilter filter;
        private final Object mLock = new Object();

        public GlycaemicIndexItemAdapter(Context context, int textViewResourceId, ArrayList<GlycaemicIndexItem> newItems) {
                super(context, textViewResourceId, newItems);
                this.items = newItems;
                cloneItems(newItems);
        }

        protected void cloneItems(ArrayList<GlycaemicIndexItem> items) {
            for (Iterator iterator = items.iterator(); iterator
            .hasNext();) {
                GlycaemicIndexItem gi = (GlycaemicIndexItem) iterator.next();
                originalItems.add(gi);
            }
        }

        @Override
        public int getCount() {
            synchronized(mLock) {
                return items!=null ? items.size() : 0;  
            }
        }

        @Override
        public GlycaemicIndexItem getItem(int item) {
            GlycaemicIndexItem gi = null;
            synchronized(mLock) {
                    gi = items!=null ? items.get(item) : null;

            }
            return gi;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
                View v = convertView;
                if (v == null) {
                    LayoutInflater vi = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                    v = vi.inflate(R.layout.row, null);
                }

                GlycaemicIndexItem i  = null;
                synchronized(mLock) {
                    i = items.get(position);
                }

                if (i != null) {
                        TextView tt = (TextView) v.findViewById(R.id.rowText);
                        TextView bt = (TextView) v.findViewById(R.id.rowText2);
                        if (tt != null) {
                              tt.setText("Name: "+i.getName());                            
                        }
                        if(bt != null){
                              bt.setText("GI Value: " + i.getGlycaemicIndex());
                        }
                }
                return v;
        }
        /**
         * Implementing the Filterable interface.
         */
        public Filter getFilter() {
            if (filter == null) {
                filter = new GlycaemicIndexItemFilter();
            }
            return filter;
        }   

        /**
         * Custom Filter implementation for the items adapter.
         *
         */
        private class GlycaemicIndexItemFilter extends Filter {
            protected FilterResults performFiltering(CharSequence prefix) {
                // Initiate our results object
                FilterResults results = new FilterResults();

                // No prefix is sent to filter by so we're going to send back the original array
                if (prefix == null || prefix.length() == 0) {
                    synchronized (mLock) {
                        results.values = originalItems;
                        results.count = originalItems.size();
                    }
                } else {
                    synchronized(mLock) {
                            // Compare lower case strings
                        String prefixString = prefix.toString().toLowerCase();
                        final ArrayList<GlycaemicIndexItem> filteredItems = new ArrayList<GlycaemicIndexItem>();
                        // Local to here so we're not changing actual array
                        final ArrayList<GlycaemicIndexItem> localItems = new ArrayList<GlycaemicIndexItem>();
                        localItems.addAll(originalItems);
                        final int count = localItems.size();

                        for (int i = 0; i < count; i++) {
                            final GlycaemicIndexItem item = localItems.get(i);
                            final String itemName = item.getName().toString().toLowerCase();

                            // First match against the whole, non-splitted value
                            if (itemName.startsWith(prefixString)) {
                                filteredItems.add(item);
                            } else {} /* This is option and taken from the source of ArrayAdapter
                                final String[] words = itemName.split(" ");
                                final int wordCount = words.length;

                                for (int k = 0; k < wordCount; k++) {
                                    if (words[k].startsWith(prefixString)) {
                                        newItems.add(item);
                                        break;
                                    }
                                }
                            } */
                        }

                        // Set and return
                        results.values = filteredItems;
                        results.count = filteredItems.size();
                    }//end synchronized
                }

                return results;
            }

            @SuppressWarnings("unchecked")
            @Override
            protected void publishResults(CharSequence prefix, FilterResults results) {
                //noinspection unchecked
                synchronized(mLock) {
                    final ArrayList<GlycaemicIndexItem> localItems = (ArrayList<GlycaemicIndexItem>) results.values;
                    notifyDataSetChanged();
                    clear();
                    //Add the items back in
                    for (Iterator iterator = localItems.iterator(); iterator
                            .hasNext();) {
                        GlycaemicIndexItem gi = (GlycaemicIndexItem) iterator.next();
                        add(gi);
                    }
                }//end synchronized
            }
        }
    }
}