我怎样才能使用baseadapter过滤listview

Question

我试图过滤listview,但getfilter方法不起作用,

这是代码:

@Override
public void afterTextChanged(Editable s) {
}

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

@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
    mHistoryAdapter.getFilter().filter(s);   
}

我已经在baseadapter中添加了该方法

public Filter getFilter() {
    return null;
}

但它没有用......可以有人帮帮我.. @谢谢

Answer 1

MainActivity.java

public class MainActivity extends Activity {

private ListView mListView;
private CustomAdapter mCustomAdapter;
private EditText mEditText;
private ArrayList<Contacts> _Contacts = new ArrayList<Contacts>();

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

    for (int i = 0; i < 100; i++) {
        Contacts contacts = new Contacts();
        contacts.setId(""+i);
        contacts.setName("Name "+i);
        _Contacts.add(contacts);
    }


    mListView = (ListView) findViewById(R.id.listView1);
    mEditText = (EditText) findViewById(R.id.editText1);

    mCustomAdapter = new CustomAdapter(MainActivity.this, _Contacts);
    mListView.setAdapter(mCustomAdapter);

    mEditText.addTextChangedListener(new TextWatcher() {

        @Override
        public void onTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) {
            mCustomAdapter.getFilter().filter(arg0);
        }

        @Override
        public void beforeTextChanged(CharSequence arg0, int arg1, int arg2,
                int arg3) {
        }

        @Override
        public void afterTextChanged(Editable arg0) {

        }
    });
}

}

CustomAdapter.java

public class CustomAdapter extends BaseAdapter implements Filterable{

private ArrayList<Contacts> _Contacts;
private Activity context;
private LayoutInflater inflater;
private ValueFilter valueFilter;
private ArrayList<Contacts> mStringFilterList;

public CustomAdapter(Activity context, ArrayList<Contacts> _Contacts) {
    super();
    this.context = context;
    this._Contacts = _Contacts;
    mStringFilterList =  _Contacts;
    this.inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
     getFilter();
}

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

@Override
public Object getItem(int position) {
    return _Contacts.get(position).getName();
}

@Override
public long getItemId(int position) {
    return 0;
}

public class ViewHolder {
    TextView tname, tplace;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    ViewHolder holder;
    if (convertView == null) {
        holder = new ViewHolder();
        convertView = inflater.inflate(R.layout.activity_main, null);
        holder.tname = (TextView) convertView.findViewById(R.id.textView1);
        holder.tplace = (TextView) convertView.findViewById(R.id.textView2);
        convertView.setTag(holder);
    } else
        holder = (ViewHolder) convertView.getTag();
    holder.tname.setText("" + _Contacts.get(position).getName());
    holder.tplace.setText("" + "" + _Contacts.get(position).getId());
    return convertView;
}

@Override
public Filter getFilter() {
    if(valueFilter==null) {

        valueFilter=new ValueFilter();
    }

    return valueFilter;
}
private class ValueFilter extends Filter {

    //Invoked in a worker thread to filter the data according to the constraint.
    @Override
    protected FilterResults performFiltering(CharSequence constraint) {
        FilterResults results=new FilterResults();
        if(constraint!=null && constraint.length()>0){
            ArrayList<Contacts> filterList=new ArrayList<Contacts>();
            for(int i=0;i<mStringFilterList.size();i++){
                if((mStringFilterList.get(i).getName().toUpperCase())
                        .contains(constraint.toString().toUpperCase())) {
                    Contacts contacts = new Contacts();
                    contacts.setName(mStringFilterList.get(i).getName());
                    contacts.setId(mStringFilterList.get(i).getId());
                    filterList.add(contacts);
                }
            }
            results.count=filterList.size();
            results.values=filterList;
        }else{
            results.count=mStringFilterList.size();
            results.values=mStringFilterList;
        }
        return results;
    }


    //Invoked in the UI thread to publish the filtering results in the user interface.
    @SuppressWarnings("unchecked")
    @Override
    protected void publishResults(CharSequence constraint,
            FilterResults results) {
        _Contacts=(ArrayList<Contacts>) results.values;
        notifyDataSetChanged();
    }
}
}

Contacts.java

public class Contacts {

private String name;
private String id;

public String getName() {
    return name;
}
public void setName(String name) {
    this.name = name;
}
public String getId() {
    return id;
}
public void setId(String id) {
    this.id = id;
}
}

main.xml中

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >

<EditText
    android:id="@+id/editText1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:ems="10" >

    <requestFocus />
</EditText>

<ListView
    android:id="@+id/listView1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" >
</ListView>

activity_main.xml中

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="2dp"
android:layout_marginLeft="1dp"
android:layout_marginRight="1dp"
android:layout_marginTop="2dp"
android:background="@android:color/black"
android:gravity="center_vertical"
android:paddingBottom="2dp"
android:paddingTop="2dp"
tools:context=".MainActivity" >


<TextView
    android:id="@+id/textView1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginLeft="8dp"
    android:text="Large Text"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:textColor="@android:color/white" />

<TextView
    android:id="@+id/textView2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginLeft="8dp"
    android:text="Small Text"
    android:textAppearance="?android:attr/textAppearanceSmall"
    android:textColor="@android:color/white" />

这是一个示例项目代码.使用此代码,这将真正帮助您

Answer 2

干得好.一个简单的baseadapter(没有视图回收),它将显示和过滤一些自定义任意对象的列表.在此示例中,Object.name是我们将用于过滤的字段.

1)在您创建ListView的活动(或)中,启用文本过滤:

class MyObject {
    public String name;
}
List<MyObject> myData = ArrayList<>();

listview.setTextFilterEnabled(true);

2)正如你已经注意到,在EDITTEXT的textwatcher,触发该过滤器ListAdapter:

public void onTextChanged(CharSequence s, int start, int before, int count) {
    listadapter.getFilter().filter(s);   
}

3)在你的baseadapter中implement Filterable.并存储两个数据副本,一个原始数据和一个过滤数据.确保访问整个BaseAdapter中的过滤数据,而不是未过滤的数据

public class FilterableListAdapterExample extends BaseAdapter implements Filterable {

private List<MyObject> mData; //the original data
private List<MyObject> mDataFiltered;//the filtered data
private LayoutInflater mLayoutInflater;

public FilterableListAdapterExample(Context context, List<MyObject> data) {
    mData = data;
    mDataFiltered=data;
    mLayoutInflater = LayoutInflater.from(context);
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    convertView= mLayoutInflater.inflate(R.layout.listview_item, null);
    TextView textview=(TextView)convertView.findViewById(R.id.listitem_textview);
    //note: we access mDataFiltered, not mData
    textview.setText(mDataFiltered.get(position).name); 
    return convertView;
}

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

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

@Override
public Filter getFilter() {
    return new Filter() {
        @Override
        protected FilterResults performFiltering(CharSequence constraint) {
            FilterResults results = new FilterResults();
            if (constraint == null || constraint.length() == 0) {
                //no constraint given, just return all the data. (no search)
                results.count = mData.size();
                results.values = mData;
            } else {//do the search
                List<MyObject> resultsData = new ArrayList<>();
                String searchStr = constraint.toString().toUpperCase();
                for (MyObject o : mData)
                    if (o.name.toUpperCase().startsWith(searchStr)) resultsData.add(o);
                results.count = resultsData.size();
                results.values = resultsData;
            }
            return results;
        }

        @Override
        protected void publishResults(CharSequence constraint, FilterResults results) {
            mDataFiltered = (ArrayList<MyObject>) results.values;
            notifyDataSetChanged();
        }
    };
}

}