Android开发（21）--有关Spinner控件的使用说明

下拉列表 Spinner，Spinner是一个每次只能选择所有项的一个项的控件。它的项来自于与之相关联的适配器中。
Spinner的使用，可以极大提高用户的体验性。当需要用户选择的时候，可以提供一个下拉列表将所有可选的项列出来。供用户选择。

一、使用数组作为数据源

布局文件：

<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/spinner1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true" />

</RelativeLayout>

MainActivity.java

package com.example.lesson16_spinner;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

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

public class MainActivity extends Activity {
	// 声明spinner对象
	private Spinner spinner;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		spinner = (Spinner) findViewById(R.id.spinner1);
		//使用数组作为数据源
		final String arr[] = new String[] { "周一", "周二", "周三", "周四", "周五", "周六",
				"周七" };
		// adpater对象
		 ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, arr);

		List<Map<String, Object>> data = new ArrayList<Map<String, Object>>();

		Map<String, Object> map = new HashMap<String, Object>();

		map.put("logo", R.drawable.ic_launcher);
		map.put("text", "xxxx说明操作");

		Map<String, Object> map2 = new HashMap<String, Object>();

		map2.put("logo", R.drawable.ic_launcher);
		map2.put("text", "xxx说明xxx");

		data.add(map);
		data.add(map2);

		SimpleAdapter simpleAdapter = new SimpleAdapter(this, data,
				R.layout.activity_item, new String[] { "logo", "text" },
				new int[] { R.id.imageView1, R.id.textView1 });
		// 设置显示的数据
		 spinner.setAdapter(arrayAdapter);

		//spinner.setAdapter(simpleAdapter);

		Toast.makeText(getApplicationContext(),"main Thread"+ spinner.getItemAtPosition(spinner.getSelectedItemPosition()), Toast.LENGTH_LONG).show();

		// 注册事件
		spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {

			@Override
			public void onItemSelected(AdapterView<?> parent, View view,
					int position, long id) {

				// String content = arr[position];

				Spinner spinner = (Spinner) parent;

				Toast.makeText(getApplicationContext(),
						"xxxx" + spinner.getItemAtPosition(position),
						Toast.LENGTH_LONG).show();

			}

			@Override
			public void onNothingSelected(AdapterView<?> parent) {
				Toast.makeText(getApplicationContext(), "没有改变的处理",
						Toast.LENGTH_LONG).show();

			}
		});

	}

	@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：

二、使用XML作为数据源（非本人代码）

布局文件：

<?xml version="1.0" encoding="utf-8"?>
<resources>
	<string-array name="plantes">
		<item>NOKIA</item>
		<item>MOTO</item>
		<item>HTC</item>
		<item>LG</item>
		<item>其他</item>
	</string-array>
</resources>

java代码：

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

public class SpinnerActivity extends Activity {

	private TextView view2;
	private Spinner spinner2;
	private ArrayAdapter adapter2;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		setContentView(R.layout.spinner);

		spinner2 = (Spinner) findViewById(R.id.spinner02);
		view2 = (TextView) findViewById(R.id.spinnerText02);

		//将可选内容与ArrayAdapter连接起来
		adapter2 = ArrayAdapter.createFromResource(this, R.array.plantes, android.R.layout.simple_spinner_item);

		//设置下拉列表的风格
 adapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

		//将adapter2 添加到spinner中
		spinner2.setAdapter(adapter2);

		//添加事件Spinner事件监听
		spinner2.setOnItemSelectedListener(new SpinnerXMLSelectedListener());

		//设置默认值
		spinner2.setVisibility(View.VISIBLE);

	}

	//使用XML形式操作
	class SpinnerXMLSelectedListener implements OnItemSelectedListener{
		public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2,
				long arg3) {
			view2.setText("你使用什么样的手机："+adapter2.getItem(arg2));
		}

		public void onNothingSelected(AdapterView<?> arg0) {

		}

	}
}