Spinner控件

示例：

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >

<TextView
android:id="@+id/textView"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
<Spinner
android:id="@+id/spinner"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
</LinearLayout>main.java
package com.example4.www;

import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.TextView;public class SpinnerActivity extends Activity {
private List<String> list = new ArrayList<String>();
private ArrayAdapter<String>adapter;
private TextView myTextView;
private Spinner mySpinner;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
myTextView = (TextView)findViewById(R.id.textView);
mySpinner = (Spinner)findViewById(R.id.spinner);
//1.添加下拉列表选项
list.add("apple");
list.add("orange");
list.add("pear");
//2.为下拉列表定义适配器
adapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,list);
//3.为适配器设置下拉列表样式
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
//4.将适配器添加到下拉列表上
mySpinner.setAdapter(adapter);
mySpinner.setPrompt("Choose you favourite fruit");
//5.设置相应事件
mySpinner.setOnItemSelectedListener(new Spinner.OnItemSelectedListener(){

public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
myTextView.setText("you favourite fruit is:" + adapter.getItem(arg2));
arg0.setVisibility(View.VISIBLE);
}
public void onNothingSelected(AdapterView<?> arg0) {
myTextView.setText("Choose you favourite fruit");
arg0.setVisibility(View.VISIBLE);
}
});
}
}知识点归纳：

1.添加下拉列表选项

2.为下拉列表定义适配器

3.为适配器设置下拉列表样式

4.将适配器添加到下拉列表上

5.设置相应事件