Android Spinner

• 新建一个Android工程，名字为SpinnerActy。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> <!– 定义一个下拉菜单–>  
  </LinearLayout> 

• 修改你的SpinnerActy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 SpinnerActy extends Activity { 
      /** Called when the activity is first created. */ 
      private List<String> list = new ArrayList<String>(); 
      private TextView myTextView; 
      private Spinner mySpinner; 
      private ArrayAdapter<String> 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<String>(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); 
          } 
          }); 
      } 
  }