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) {

}

}
}