MainActivity如下:

package cc.testautocompletetextview;

import cc.testautocompletetextview1.R;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;
import android.app.Activity;
/**
 * Demo描述
 * AutoCompleteTextView基本使用完整示例
 * 
 * 注意参数:
 * android:completionThreshold="2"
 * 
 * 参考资料:
 * 《疯狂Android讲义》 作者李刚
 *  Thank you very much
 */
public class MainActivity extends Activity {
	private AutoCompleteTextView mAutoCompleteTextView;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		init();
	}
   
	private void init(){
		mAutoCompleteTextView=(AutoCompleteTextView) findViewById(R.id.autoCompleteTextView);
		String [] emails=new String []{"111@126.com","111@sina.com","111@sohu.cn","111@qq.com"};
		ArrayAdapter<String> arrayAdapter
		=new ArrayAdapter<String>(this, android.R.layout.simple_dropdown_item_1line, emails);
		mAutoCompleteTextView.setAdapter(arrayAdapter);
	}
	

}

main.xml如下:

<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"
     >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="AutoCompleteTextView使用示例" 
        android:layout_centerHorizontal="true"/>
    
    <AutoCompleteTextView 
        android:id="@+id/autoCompleteTextView"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="30dip"
        android:completionHint="请选择:"
        android:dropDownVerticalOffset="2dip"
        android:dropDownHorizontalOffset="2dip"
        android:completionThreshold="2"
    />

</RelativeLayout>

Android中AutoCompleteTextView完整示例(一)