Android之实现“抽奖大轮盘” _Android

一年好景君须记，最是橙黄橘绿时。这篇文章主要讲述Android之实现“抽奖大轮盘”相关的知识，希望能为你提供帮助。
这个实例能够帮助我们学习旋转动画和计时器这两个知识点，废话不多说，上主程序：

package com.bear.lotterywheel; import java.util.Timer; import java.util.TimerTask; import android.app.Activity; import android.os.Bundle; import android.os.Handler; import android.view.Menu; import android.view.View; import android.view.View.OnClickListener; import android.view.animation.Animation.AnimationListener; import android.view.animation.Animation; import android.view.animation.RotateAnimation; import android.widget.ImageView; import android.widget.Toast; public class MainActivity extends Activity { //设置一个时间常量，此常量有两个作用，1.圆灯视图显示与隐藏中间的切换时间；2.指针转一圈所须要的时间。现设置为500毫秒 private static final long ONE_WHEEL_TIME = 500; //记录圆灯视图是否显示的布尔常量 private boolean lightsOn = true; //開始转动时候的角度，初始值为0 private int startDegree = 0; private ImageView lightIv; private ImageView pointIv; private ImageView wheelIv; //指针转圈圈数数据源 private int[] laps = { 5, 7, 10, 15 }; //指针所指向的角度数据源，由于有6个选项，全部此处是6个值 private int[] angles = { 0, 60, 120, 180, 240, 300 }; //转盘内容数组 private String[] lotteryStr = { "索尼PSP", "10元红包", "谢谢參与", "DNF钱包", "OPPO MP3", "5元红包", }; //子线程与UI线程通信的handler对象 private Handler mHandler = new Handler() {public void handleMessage(android.os.Message msg) { switch (msg.what) { case 0: if (lightsOn) { // 设置lightIv不可见 lightIv.setVisibility(View.INVISIBLE); lightsOn = false; } else { // 设置lightIv可见 lightIv.setVisibility(View.VISIBLE); lightsOn = true; } break; default: break; } }; }; //监听动画状态的监听器 private AnimationListener al = new AnimationListener() {@Override public void onAnimationStart(Animation animation) { // TODO Auto-generated method stub}@Override public void onAnimationRepeat(Animation animation) { // TODO Auto-generated method stub}@Override public void onAnimationEnd(Animation animation) { String name = lotteryStr[startDegree % 360 / 60]; Toast.makeText(MainActivity.this, name, Toast.LENGTH_LONG).show(); } }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); setupViews(); flashLights(); pointIv.setOnClickListener(new OnClickListener() {@Override public void onClick(View v) { int lap = laps[(int) (Math.random() * 4)]; int angle = angles[(int) (Math.random() * 6)]; //每次转圈角度增量 int increaseDegree = lap * 360 + angle; //初始化旋转动画，后面的四个參数是用来设置以自己的中心点为圆心转圈 RotateAnimation rotateAnimation = new RotateAnimation( startDegree, startDegree + increaseDegree, RotateAnimation.RELATIVE_TO_SELF, 0.5f, RotateAnimation.RELATIVE_TO_SELF, 0.5f); //将最后的角度赋值给startDegree作为下次转圈的初始角度 startDegree += increaseDegree; //计算动画播放总时间 long time = (lap + angle / 360) * ONE_WHEEL_TIME; //设置动画播放时间 rotateAnimation.setDuration(time); //设置动画播放完后，停留在最后一帧画面上 rotateAnimation.setFillAfter(true); //设置动画的加速行为，是先加速后减速 rotateAnimation.setInterpolator(MainActivity.this, android.R.anim.accelerate_decelerate_interpolator); //设置动画的监听器 rotateAnimation.setAnimationListener(al); //開始播放动画 pointIv.startAnimation(rotateAnimation); } }); } private void setupViews(){ lightIv = (ImageView) findViewById(R.id.light); pointIv = (ImageView) findViewById(R.id.point); wheelIv = (ImageView) findViewById(R.id.main_wheel); } //控制灯圈动画的方法 private void flashLights() {Timer timer = new Timer(); TimerTask tt = new TimerTask() {@Override public void run() { // 向UI线程发送消息 mHandler.sendEmptyMessage(0); } }; // 每隔ONE_WHEEL_TIME毫秒执行tt对象的run方法 timer.schedule(tt, 0, ONE_WHEEL_TIME); } @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; }}

【Android之实现“抽奖大轮盘”】

效果图例如以下：