Spinner 讲解

该网页将的比较详细

     http://wenku.baidu.com/view/1810e330ee06eff9aef807d8.html

下面比较简单的讲解：

    

 package com.ghg.Spinner;

 import android.app.Activity;
 import android.os.Bundle;
 import android.widget.ArrayAdapter;
 import android.widget.Spinner;

 public class Day0607_SpinnerActivity extends Activity {
     /** Called when the activity is first created. */
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.main);
         initView();
     }
     Spinner spinner;
     String[] arr=new String[] {"左对齐","右对齐","上对齐","下对齐","局中对齐"};
     private void initView() {
         // TODO Auto-generated method stub
         spinner=(Spinner) findViewById(R.id.spinner);
         ArrayAdapter<String> adapter=new ArrayAdapter<String>(this, android.R.layout.simple_dropdown_item_1line, arr);
         spinner.setAdapter(adapter);
     }
 }

在Android的UI开发中，Spinner(下拉列表)总是可以用到的，一个简单的自定义Spinner制作我们只需要记住这重要的五步，一个Spinner就可以应用而生了。

(1)新建一个Android工程，名字为SpinnerTest1。修改layout下的main.xml，添加一个Textview和一个Spinner，文件内容如下：

  xml   version = "1.0"   encoding = "utf-8" ?>
 < LinearLayout
     android:id = "@+id/widget28"
     android:layout_width = "fill_parent"
     android:layout_height = "fill_parent"
     android:orientation = "vertical"
     xmlns:android = "http://schemas.android.com/apk/res/android"   >
     < TextView
         android:id = "@+id/TextView_Show"
         android:layout_width = "fill_parent"
         android:layout_height = "wrap_content"
         android:text = "你选择的是"
         android:textSize = "25sp" >
      TextView >
     < Spinner
         android:id = "@+id/spinner_City"
         android:layout_width = "fill_parent"
         android:layout_height = "wrap_content" >
      Spinner >
  LinearLayout >

 xml version="1.0" encoding="utf-8"?>
 <LinearLayout
     android:id="@+id/widget28"
     android:layout_width="fill_parent"
     android:layout_height="fill_parent"
     android:orientation="vertical"
     xmlns:android="http://schemas.android.com/apk/res/android" >
     <TextView
         android:id="@+id/TextView_Show"
         android:layout_width="fill_parent"
         android:layout_height="wrap_content"
         android:text="你选择的是"
         android:textSize="25sp">
     TextView>
     <Spinner
         android:id="@+id/spinner_City"
         android:layout_width="fill_parent"
         android:layout_height="wrap_content">
     Spinner>
 LinearLayout>

 (2)修改你的SpinnerTest1类，在这里我们就要记住五步 来自定义一个Spinner了，完整代码及五步注释如下：

 package  com.xtlh.spinner;

 import  java.util.ArrayList;
 import  java.util.List;

 import  android.app.Activity;
 import  android.os.Bundle;
 import  android.view.MotionEvent;
 import  android.view.View;
 import  android.view.View.OnTouchListener;
 import  android.view.animation.Animation;
 import  android.view.animation.AnimationUtils;
 import  android.widget.AdapterView;
 import  android.widget.ArrayAdapter;
 import  android.widget.Spinner;
 import  android.widget.TextView;

 public   class  SpinnerTest1  extends  Activity {
     /** Called when the activity is first created. */
     private  List list =  new  ArrayList();
     private  TextView myTextView;
     private  Spinner mySpinner;
     private  ArrayAdapter adapter;
     private  Animation myAnimation;
     @Override
     public   void  onCreate(Bundle savedInstanceState) {
         super .onCreate(savedInstanceState);
         setContentView(R.layout.main);
         //第一步：添加一个下拉列表项的list，这里添加的项就是下拉列表的菜单项
         list.add("北京" );
         list.add("上海" );
         list.add("深圳" );
         list.add("南京" );
         list.add("重庆" );
         myTextView = (TextView)findViewById(R.id.TextView_Show);
         mySpinner = (Spinner)findViewById(R.id.spinner_City);
         //第二步：为下拉列表定义一个适配器，这里就用到里前面定义的list。
         adapter = new  ArrayAdapter( this ,android.R.layout.simple_spinner_item, list);
         //第三步：为适配器设置下拉列表下拉时的菜单样式。
         adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
         //第四步：将适配器添加到下拉列表上
         mySpinner.setAdapter(adapter);
         //第五步：为下拉列表设置各种事件的响应，这个事响应菜单被选中
         mySpinner.setOnItemSelectedListener(new  Spinner.OnItemSelectedListener(){
             public   void  onItemSelected(AdapterView arg0, View arg1,  int  arg2,  long  arg3) {
                 // TODO Auto-generated method stub
                 /* 将所选mySpinner 的值带入myTextView 中*/
                 myTextView.setText("您选择的是：" + adapter.getItem(arg2));
                 /* 将mySpinner 显示*/
                 arg0.setVisibility(View.VISIBLE);
             }
             public   void  onNothingSelected(AdapterView arg0) {
                 // TODO Auto-generated method stub
                 myTextView.setText("NONE" );
                 arg0.setVisibility(View.VISIBLE);
             }
         });
         /*下拉菜单弹出的内容选项触屏事件处理*/
         mySpinner.setOnTouchListener(new  Spinner.OnTouchListener(){
             public   boolean  onTouch(View v, MotionEvent event) {
                 // TODO Auto-generated method stub
                 /* 将mySpinner 隐藏，不隐藏也可以，看自己爱好*/
                 v.setVisibility(View.INVISIBLE);
                 return   false ;
             }
         });
         /*下拉菜单弹出的内容选项焦点改变事件处理*/
         mySpinner.setOnFocusChangeListener(new  Spinner.OnFocusChangeListener(){
         public   void  onFocusChange(View v,  boolean  hasFocus) {
         // TODO Auto-generated method stub
             v.setVisibility(View.VISIBLE);
         }
         });
     }
 }

 package com.xtlh.spinner;

 import java.util.ArrayList;
 import java.util.List;

 import android.app.Activity;
 import android.os.Bundle;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.View.OnTouchListener;
 import android.view.animation.Animation;
 import android.view.animation.AnimationUtils;
 import android.widget.AdapterView;
 import android.widget.ArrayAdapter;
 import android.widget.Spinner;
 import android.widget.TextView;

 public class SpinnerTest1 extends Activity {
     /** Called when the activity is first created. */
     private List list = new ArrayList();
     private TextView myTextView;
     private Spinner mySpinner;
     private ArrayAdapter adapter;
     private Animation myAnimation;
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.main);
         //第一步：添加一个下拉列表项的list，这里添加的项就是下拉列表的菜单项
         list.add("北京");
         list.add("上海");
         list.add("深圳");
         list.add("南京");
         list.add("重庆");
         myTextView = (TextView)findViewById(R.id.TextView_Show);
         mySpinner = (Spinner)findViewById(R.id.spinner_City);
         //第二步：为下拉列表定义一个适配器，这里就用到里前面定义的list。
         adapter = new ArrayAdapter(this,android.R.layout.simple_spinner_item, list);
         //第三步：为适配器设置下拉列表下拉时的菜单样式。
         adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
         //第四步：将适配器添加到下拉列表上
         mySpinner.setAdapter(adapter);
         //第五步：为下拉列表设置各种事件的响应，这个事响应菜单被选中
         mySpinner.setOnItemSelectedListener(new Spinner.OnItemSelectedListener(){
             public void onItemSelected(AdapterView arg0, View arg1, int arg2, long arg3) {
                 // TODO Auto-generated method stub
                 /* 将所选mySpinner 的值带入myTextView 中*/
                 myTextView.setText("您选择的是："+ adapter.getItem(arg2));
                 /* 将mySpinner 显示*/
                 arg0.setVisibility(View.VISIBLE);
             }
             public void onNothingSelected(AdapterView arg0) {
                 // TODO Auto-generated method stub
                 myTextView.setText("NONE");
                 arg0.setVisibility(View.VISIBLE);
             }
         });
         /*下拉菜单弹出的内容选项触屏事件处理*/
         mySpinner.setOnTouchListener(new Spinner.OnTouchListener(){
             public boolean onTouch(View v, MotionEvent event) {
                 // TODO Auto-generated method stub
                 /* 将mySpinner 隐藏，不隐藏也可以，看自己爱好*/
                 v.setVisibility(View.INVISIBLE);
                 return false;
             }
         });
         /*下拉菜单弹出的内容选项焦点改变事件处理*/
         mySpinner.setOnFocusChangeListener(new Spinner.OnFocusChangeListener(){
         public void onFocusChange(View v, boolean hasFocus) {
         // TODO Auto-generated method stub
             v.setVisibility(View.VISIBLE);
         }
         });
     }
 }