这应该是一件很简单的事情.用户将手指放在屏幕上并拖动屏幕. onTouch上有两个事件触发：
> MotionEvent.ACTION_DOWN
> MotionEvent.ACTION_MOVE
现在,如何计算ACTION_MOVE手势的速度？用户在手势时拖动手指的速度较慢或者更快,所以我想我需要计算两个中间触点之间的速度：lastTouchedPointX,lastTouchedPointY和event.getX(),event.getY().
以前有人做过吗？
解决方法
@Override
public boolean onTouchEvent(MotionEvent event,MapView mapView) {
if(event.getAction() == MotionEvent.ACTION_DOWN) {
oldX = event.getX();
oldY = event.getY();
//start timer
} else if (event.getAction() == MotionEvent.ACTION_UP) {
//long timerTime = getTime between two event down to Up
newX = event.getX();
newY = event.getY();
float distance = Math.sqrt((newX-oldX) * (newX-oldX) + (newY-oldY) * (newY-oldY));
float speed = distance / timerTime;
}
}