① 新建项目，在 res 目录下新建一个 anim 文件夹，存放动画效果用，在其中新建一个 my_anim.xml 文 件
② 在 res 目录下的 layout 文件夹中新建一个 myspinner_dropdown.xml 文件，用来存放下拉菜单弹出内 容的布局
③ 修改 main.xml，添加 UI 元素
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<translate
android:fromXDelta="0"
android:toXDelta="-100%p"
android:duration="300">
</translate><!--位置转换动画效果 -->
<alpha
android:fromAlpha="3.0"
android:toAlpha="6.0"
android:duration="300">
</alpha><!--透明度转换动画效果 -->
</set>
<?xml version="1.0" encoding="utf-8"?>
<TextView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/text1"
android:layout_width="wrap_content"
android:layout_height="24sp"
android:singleLine="true"
style="?android:attr/spinnerDropDownItemStyle"
/>
<?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"
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④ 定义一个下拉菜单
⑤ 定义一个字符串数组和一个 ArrayAdepter
⑥ 给下拉菜单内容设置样式
⑦ 给下拉菜单设置内容适配器
⑧ 给下拉菜单添加动画
⑨ mainActivity.java 完整代码 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>
private private private
private Spinner mySpinner;
/* 以 findViewById() 取得对象 */
mySpinner = (Spinner) findViewById(R.id.spinner_City);
private private private
private staticstaticstaticstatic finalfinalfinalfinal String[] countriesStr = { " 北京市 ", " 上海市 ", " 天津市 ", " 重庆市 " };
private private private
private ArrayAdapter<String> adapter;
adapter=newnewnewnew ArrayAdapter<String>(thisthisthisthis,
android.R.layout.simple_spinner_item, countriesStr);
/* myspinner_dropdown 为自定义下拉菜单样式定义在 res/layout 目录下 */
adapter.setDropDownViewResource(R.layout.myspinner_dropdown);
/* 将 ArrayAdapter 添加 Spinner 对象中 */
mySpinner.setAdapter(adapter);
/* 取得Animation 定义在res/anim 目录下*/
myAnimation = AnimationUtils.loadAnimation(thisthisthisthis, R.anim.my_anim);
/* 将mySpinner 运行Animation */
mySpinner.startAnimation(myAnimation);
package package package
package zyf.Ex_Ctrl_8;
import import import
import android.app.Activity;
import import import
import android.os.Bundle;
9
import import import
import android.view.MotionEvent;
import import import
import android.view.View;
import import import
import android.view.animation.Animation;
import import import
import android.view.animation.AnimationUtils;
import import import
import android.widget.AdapterView;
import import import
import android.widget.ArrayAdapter;
import import import
import android.widget.Spinner;
import import import
import android.widget.TextView;
public public public
public classclassclassclass Ex_Ctrl_8 extendsextendsextendsextends Activity {
/** Called when the activity is first created. */
private private private
private staticstaticstaticstatic finalfinalfinalfinal String[] countriesStr = { " 北京市 ", " 上海市 ", " 天津市 ", " 重庆市 " };
private private private
private TextView myTextView;
private private private
private Spinner mySpinner;
private private private
private ArrayAdapter<String> adapter;
Animation myAnimation;
@Override public public public
public voidvoidvoidvoid onCreate(Bundle savedInstanceState) { super
super super
super.onCreate(savedInstanceState);
/* 载入 main.xml Layout */
setContentView(R.layout.main);
/* 以 findViewById() 取得对象 */
myTextView = (TextView) findViewById(R.id.TextView_Show);
mySpinner = (Spinner) findViewById(R.id.spinner_City);
/* 取得Animation 定义在res/anim 目录下*/
myAnimation = AnimationUtils.loadAnimation(thisthisthisthis, R.anim.my_anim);
adapter=newnewnewnew ArrayAdapter<String>(thisthisthisthis, android.R.layout.simple_spinner_item, countriesStr);
/* myspinner_dropdown 为自定义下拉菜单样式定义在 res/layout 目录下 */
adapter.setDropDownViewResource(R.layout.myspinner_dropdown);
/* 将 ArrayAdapter 添加 Spinner 对象中 */
mySpinner.setAdapter(adapter);
/*下拉菜单弹出的内容选项被选中事件处理*/
mySpinner.setOnItemSelectedListener(newnewnewnew
Spinner.OnItemSelectedListener(){
public public public
public voidvoidvoidvoid onItemSelected(AdapterView<?> arg0, View arg1, int
int int
int arg2, longlonglonglong arg3) { // TODOTODOTODOTODO Auto-generated method stub
/* 将所选mySpinner 的值带入myTextView 中*/
myTextView.setText("您选择的是："+ countriesStr[arg2]);
/* 将mySpinner 显示*/
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⑩ 结果 }
public public public
public voidvoidvoidvoid onNothingSelected(AdapterView<?> arg0) { // TODOTODOTODOTODO Auto-generated method stub
myTextView.setText("NONE");
} });
/*下拉菜单弹出的内容选项 触屏事件处理*/
mySpinner.setOnTouchListener(newnewnewnew Spinner.OnTouchListener(){
public public public
public booleanbooleanbooleanboolean onTouch(View v, MotionEvent event) { // TODOTODOTODOTODO Auto-generated method stub
/* 将mySpinner 运行Animation */
v.startAnimation(myAnimation);
/* 将mySpinner 隐藏*/
v.setVisibility(View.INVISIBLE);
return return return
return falsefalsefalsefalse;
} });
/*下拉菜单弹出的内容选项 焦点改变事件处理*/
mySpinner.setOnFocusChangeListener(newnewnewnew Spinner.OnFocusChangeListener(){
public public public
public voidvoidvoidvoid onFocusChange(View v, booleanbooleanbooleanboolean hasFocus) { // TODOTODOTODOTODO Auto-generated method stub
} });
} }