AutoCompleteTextView和自定义的CursorAdapter
? ? ? AutoCompleteTextView配合自定义的CursorAdapter（setAdapter()）,可以帮助我们完成查找的功能.关键就在于类CursorAdapter.
????? CursorAdapter是继承自BaseAdapter并且实现了接口Filterable?。所以在我们自己定义的CursorAdapter子类中就不需要在继承Filterable，但对于JRE是1.5以下的虚拟机来说。是要重写方法getFilter()的；
????? 要继承CursorAdapter类。必须实现的方法有：
?????? 1）首先执行的是public Cursor runQueryOnBackgroundThread(CharSequence constraint),constraint就是我们输入的要查询的关键字；此方法产生查询到的所有数据的cursor.并将其返回给下一个函数；
?????? 2）接下来执行方法public View newView(Context context, Cursor cursor, ViewGroup parent)，cursor就是有第一种方法产生的.这个方法主要是产生一个个具体的承载cursor指向的数据的view类，最常见的是TextView;
?????? 3）接下来执行方法public void bindView(View view, Context context, Cursor cursor) 。view就是第2步产生的。cursor是第一步产生的。显而易见，就是将两者进行绑定。
??????? 但要注意的是，2和3是反复交替执行的。产生多少条数据（cursor.getcount()）就执行多少轮。还有一点容易忽视的就是在xml文件中定义AutoCompleteTextView片段中一定要加入以下代码android:completionThreshold="1"，他表示你最少要输入关键字的个数；
??????? 下面的代码以查询联系人为例：
package com.zymic.home;import android.app.Activity;import android.content.ContentResolver;import android.content.Context;import android.database.Cursor;import android.os.Bundle;import android.provider.Contacts;import android.provider.Contacts.People;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.AutoCompleteTextView;import android.widget.CursorAdapter;import android.widget.Filterable;import android.widget.TextView;import android.widget.Toast;public class AutoTextViewEx extends Activity { private AutoCompleteTextView autoTextView; private Cursor cursor; // private static final String[] PEOPLE_PROJECTION = new String[] { Contacts.People._ID, Contacts.People.PRIMARY_PHONE_ID, Contacts.People.TYPE, Contacts.People.NUMBER, Contacts.People.LABEL, Contacts.People.NAME, }; // @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); // autoTextView=(AutoCompleteTextView)findViewById(R.id.autotextview); cursor=getApplicationContext().getContentResolver().query(People.CONTENT_URI, PEOPLE_PROJECTION, null, null, null); MyAdapter adapter=new MyAdapter(this,cursor); autoTextView.setAdapter(adapter); } // public class MyAdapter extends CursorAdapter implements Filterable{ Cursor cursor;public MyAdapter(Context context, Cursor c) {super(context, c);// TODO Auto-generated constructor stub}@Overridepublic void bindView(View view, Context context, Cursor cursor) {((TextView)view).setText(cursor.getString(5));Toast.makeText(getApplicationContext(), "bindView", Toast.LENGTH_SHORT).show();}@Overridepublic View newView(Context context, Cursor cursor, ViewGroup parent) {LayoutInflater inflater = (LayoutInflater)context.getSystemService ( Context.LAYOUT_INFLATER_SERVICE);TextView view=(TextView) inflater.inflate(android.R.layout.simple_dropdown_item_1line, null);//view.setText(cursor.getString(5));Toast.makeText(getApplicationContext(), "newView", Toast.LENGTH_SHORT).show();return view;}@Overridepublic Cursor runQueryOnBackgroundThread(CharSequence constraint) {//UPPER(Contacts.People.NAME)String where="UPPER("+Contacts.People.NAME+") GLOB ?";String[]to=new String[]{"*"+constraint.toString().toUpperCase()+"*"};cursor=getApplicationContext().getContentResolver().query(People.CONTENT_URI, PEOPLE_PROJECTION,where, to, null);//System.out.println(cursor);Toast.makeText(getApplicationContext(), "runQuery", Toast.LENGTH_SHORT).show();return cursor;} }}?