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public class TestFilter extends ListActivity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ArrayList<HashMap<String,String>> list = new
ArrayList <HashMap<String, String>>();
HashMap<String, String> map1 = new HashMap<String, String>();
HashMap<String, String> map2 = new HashMap<String, String>();
HashMap<String, String> map3 = new HashMap<String, String>();
map1.put("name", "henly");
map1.put("age", "22");
map2.put("name", "john");
map2.put("age", "23");
map3.put("name", "lilei");
map3.put("age", "22");
list.add(map1);
list.add(map2);
list.add(map3);
SimpleAdapter simpleAdapter = new SimpleAdapter(this, list, R.layout.user, new String[]{"name","age"}, new int[]{R.id.name,R.id.age});
String str = new String("22");
CharSequence constraint = str.subSequence(0, str.length());
Filter filter = simpleAdapter.getFilter(); //得到一个过滤器
filter.filter(constraint); //为该过滤器设置约束条件
setListAdapter(simpleAdapter);
}
}
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<LinearLayout android:id="@+id/listlinearlayout"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<ListView android:id="@id/android:list"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:drawSelectorOnTop="false"
android:scrollbars="vertical" />
</LinearLayout>
</LinearLayout>
user.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:paddingLeft="12dip"
android:paddingRight="12dip"
android:paddingTop="1dip"
android:paddingBottom="1dip"
>
<TextView android:id="@+id/name"
android:layout_width="150dip"
android:layout_height="30dip"
android:textSize="12pt"
/>
<TextView android:id="@+id/age"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="12pt"
/>
</LinearLayout>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<EditText
android:id="@+id/searchbox"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:drawableLeft="@drawable/searchbox"
android:hint="Search"
android:drawablePadding="5dp"
android:singleLine="true"
android:ems="10" >
<requestFocus />
</EditText>
<ListView
android:id="@android:id/list"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/searchbox">
</ListView>
</RelativeLayout>
要让数据有过滤功能，我们需要在继承的BaseAdapter的基础上再实现Filterable接口的getFilter方法，同时在Adapter内部写一个继承Filter的内部类来完成过滤功能：
private class ListAdapter extends BaseAdapter implements Filterable {
private List<Person> list;
private Context context;
private PersonFilter filter;
public ListAdapter(List<Person> list, Context context) {
this.list = list;
this.context = context;
}
@Override
public int getCount() {
return list.size();
}
@Override
public Object getItem(int position) {
return list.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (convertView == null) {
convertView = LayoutInflater.from(context).inflate(R.layout.list_item, null);
}
Person p = list.get(position);
TextView firstname = (TextView)convertView.findViewById(R.id.firstname);
TextView lastname = (TextView)convertView.findViewById(R.id.lastname);
TextView age = (TextView)convertView.findViewById(R.id.age);
firstname.setText(p.firstname);
lastname.setText(p.lastname);
age.setText(p.age + "");
return convertView;
}
@Override
public Filter getFilter() {
if (filter == null) {
filter = new PersonFilter(list);
}
return filter;
}
private class PersonFilter extends Filter {
private List<Person> original;
public PersonFilter(List<Person> list) {
this.original = list;
}
@Override
protected FilterResults performFiltering(CharSequence constraint) {
FilterResults results = new FilterResults();
if (constraint == null || constraint.length() == 0) {
results.values = original;
results.count = original.size();
} else {
List<Person> mList = new ArrayList<Person>();
for (Person p: original) {
if (p.firstname.toUpperCase().startsWith(constraint.toString().toUpperCase())
|| p.lastname.toUpperCase().startsWith(constraint.toString().toUpperCase())
|| new String(p.age + "").toUpperCase().startsWith(constraint.toString().toUpperCase())) {
mList.add(p);
}
}
results.values = mList;
results.count = mList.size();
}
return results;
}
@Override
protected void publishResults(CharSequence constraint,
FilterResults results) {
list = (List<Person>)results.values;
notifyDataSetChanged();
}
}
}
Filter类中的两个方法看名字就是知道一个是执行过滤的，一个刷新listview数据展现结果的。其中我采用了前缀匹配，就是用输入的字符串和ListView里的所有Person的各个属性的前缀做比较。也可以用更加复杂的匹配，例如正则表达式。
private class Person {
public String firstname;
public String lastname;
public int age;
public Person(String firtname, String lastname, int age) {
this.firstname = firtname;
this.lastname = lastname;
this.age = age;
}
}
<?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="horizontal" >
<TextView
android:id="@+id/firstname"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:text="Firstname" />
<TextView
android:id="@+id/lastname"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:text="Lastname" />
<TextView
android:id="@+id/age"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:text="Age" />
</LinearLayout>
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原文地址：http://blog.csdn.net/robertcpp/article/details/51523375
