android实战教程--控件篇（Spinner下拉框）

Spinner是android系统提供的一个弹出式下拉框，以下是使用Spinner控件的一个实例：

修改activity_main.xml文件：

<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=".MainActivity" >

    <Spinner 
        android:id="@+id/vocation"
        android:prompt="@string/vocation"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
    <Spinner 
        android:id="@+id/sex"
        android:prompt="@string/sex"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/vocation"/>

</RelativeLayout>

修改string.xml文件：

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">Demo</string>
    <string name="action_settings">Settings</string>
    <string name="hello_world">Hello world!</string>
	<string name="vocation">您的职业</string>
	<string name="sex">您的性别</string>
	<string-array name="vacationList">
	    <item>学生</item>
	    <item>技工</item>
	    <item>前台</item>
		<item >工程师</item>	    
	</string-array>
	<string-array name="sexList">
	    <item >男</item>
	    <item>女</item>
	</string-array>
</resources>

修改MainActivity.java文件：

package com.example.demo;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.ArrayAdapter;
import android.widget.Spinner;

public class MainActivity extends Activity {
	private Spinner sp1;
	private Spinner sp2;
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		sp1=(Spinner) this.findViewById(R.id.vocation);
		sp2=(Spinner) this.findViewById(R.id.sex);
		
		ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this, R.array.vacationList, android.R.layout.simple_spinner_dropdown_item);
		adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
		sp1.setAdapter(adapter);
		
		sp1.setOnItemSelectedListener(new OnItemSelectedListener() {

			@Override
			public void onItemSelected(AdapterView<?> parent, View v,
					int position, long id) {
				// TODO Auto-generated method stub
				setTitle("选择了"+sp1.getSelectedItem().toString());
			}

			@Override
			public void onNothingSelected(AdapterView<?> arg0) {
				// TODO Auto-generated method stub
				setTitle("还没选中");
			}
		});
		
		adapter=ArrayAdapter.createFromResource(this, R.array.sexList, android.R.layout.simple_spinner_dropdown_item);
		adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
		sp2.setAdapter(adapter);
		sp2.setOnItemSelectedListener(new OnItemSelectedListener() {

			@Override
			public void onItemSelected(AdapterView<?> parent, View v,
					int position, long id) {
				// TODO Auto-generated method stub
				setTitle("选择了"+sp2.getSelectedItem().toString());
			}

			@Override
			public void onNothingSelected(AdapterView<?> arg0) {
				// TODO Auto-generated method stub
				setTitle("还没选中");
			}
		});
		
	}

	@Override
	public 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;
	}

}

效果如下：