Android 列表单选对话框

<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="com.example.test10.MainActivity" >

    <Button 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button1"
        android:onClick="btnOnclick"/>

</RelativeLayout>

package com.example.test10;

import android.support.v7.app.ActionBarActivity;
import android.app.AlertDialog;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;

public class MainActivity extends ActionBarActivity {
	private AlertDialog dlg;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		createSingle();
	}
	public void createSingle(){
		final String[] items={"AAA","BBB","CCC","DDD"}; 
		dlg=new AlertDialog.Builder(this)
		.setIcon(R.drawable.ic_launcher)
		.setTitle("列表对话框")
		.setSingleChoiceItems(items, 0, null)
		.setPositiveButton("确定", null)
		.create();
	}
	public void btnOnclick(View view){
		dlg.show();
	}
}