天天记录 - 使用VelocityTracker计算滑动速率

来源：互联网发布：淘宝开店过程心得体会编辑：程序博客网时间：2024/06/05 11:58

先看看效果图

使用比较简单，直接贴代码

/** * 计算滑动速率 *  */public class VelocityTrackerDemoActivity extends Activity {private static final String INFO = "手指在屏幕上滑动";    private int mMaximumVelocity;private VelocityTracker mVelocityTracker;private TextView mTextView;@Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);                mTextView = (TextView) findViewById(R.id.textView);        mTextView.setText(INFO);                final ViewConfiguration configuration = ViewConfiguration.get(this);        mMaximumVelocity = configuration.getScaledMaximumFlingVelocity();    }@Overridepublic boolean onTouchEvent(MotionEvent event) {int action = event.getAction();if (mVelocityTracker == null) {// 获得VelocityTracker类的一个实例对象mVelocityTracker = VelocityTracker.obtain();} // 添加跟踪// 将当前的移动事件传递给VelocityTracker对象mVelocityTracker.addMovement(event);switch (action) {case MotionEvent.ACTION_MOVE://mTracker.addMovement(event);// 计算当前的速度// 1000,初始化速率的单位 表示每秒多少像素（pix/second),1代表每微秒多少像素（pix/millisecond)。final VelocityTracker velocityTracker = mVelocityTracker;            velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);mTextView.setText(INFO + " \n横向速率是 ： "+mVelocityTracker.getXVelocity());    mTextView.append("\n 纵向速率是： "+mVelocityTracker.getYVelocity());break;case MotionEvent.ACTION_CANCEL:// 这里可以获取滑动的速率if (mVelocityTracker != null) {mVelocityTracker.recycle();mVelocityTracker = null;}break;}return true;}}