struct ifreq ifr; 
int fd; 
fd=socket(AF_INET,SOCK_DGRAM,0); 
strcpy(ifr.ifr_name,"eth0"); 
ifr.ifr_addr.sa_family=AF_INET; 
ioctl(fd,SIOCGIFHWADDR,&ifr); 
puts(ifr.ifr_hwaddr.sa_data); 

      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
		}

		@Override
		public void bindView(View view, Context context, Cursor cursor) {
			((TextView)view).setText(cursor.getString(5));
			Toast.makeText(getApplicationContext(), "bindView", Toast.LENGTH_SHORT).show();
		}

		@Override
		public 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;
		}

		@Override
		public 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;
		}
    	
    	
    }
}