Android,ListView的使用

package com.example.atest25;import android.os.Bundle;import android.app.Activity;import android.view.Menu;import android.widget.ArrayAdapter;import android.widget.ListView;public class MainActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);String[] str1 = {"aaa","bbb","ccc","ddd","eee","fff","ggg","hhh","iii","jjj","kkk","lll","mmm","nnn","ooo"};ListView list1 = (ListView)findViewById(R.id.listView1);ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(MainActivity.this, android.R.layout.simple_list_item_1,str1);list1.setAdapter(arrayAdapter);}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:id="@+id/LinearLayout1"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical"    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" >    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content" >                <TextView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="按类型查询" />        <Spinner            android:id="@+id/spinner1"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_weight="1" />        <Button            android:id="@+id/button1"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="Button" />                    </LinearLayout>        <ListView        android:id="@+id/listView1"        android:layout_width="match_parent"        android:layout_height="wrap_content" >    </ListView></LinearLayout>