通过onTouchEvent判断是否为双击事件，通过前面一次up 跟本次down之间的时间差，并且点击的点的坐标偏移来确定是否为双击事件DOUBLE_TAP_TIMEOUT。

boolean isMove = false;        private final int DOUBLE_TAP_TIMEOUT = 200;        private MotionEvent mCurrentDownEvent;        private boolean mDoubleTapEnabled = false;        private MotionEvent mPreviousUpEvent;        @Override        public void onTouchEvent(MotionEvent event) {            Log.e(LOG_TAG, "MotionEvent="+ event.getAction()+",isMove="+isMove);            Log.e(LOG_TAG, "mPreviousUpEvent="+ mPreviousUpEvent+",mCurrentDownEvent="+mCurrentDownEvent);            if (event.getAction() == MotionEvent.ACTION_MOVE) {                                isMove = true;            }            else if (event.getAction() == MotionEvent.ACTION_DOWN) {                if (mPreviousUpEvent != null && mCurrentDownEvent != null                         && isConsideredDoubleTap(mCurrentDownEvent, mPreviousUpEvent, event)                        ) {                    if (mDoubleTapEnabled && Environment.getExternalStorageState().equals("mounted")) {                                                Toast.makeText(getApplicationContext(), getResources().getString(R.string.double_click), Toast.LENGTH_LONG).show();                                            }                }                mCurrentDownEvent = MotionEvent.obtain(event);            }else if (event.getAction() == MotionEvent.ACTION_UP){                mPreviousUpEvent = MotionEvent.obtain(event);                isMove = false;            }        }        private boolean isConsideredDoubleTap(MotionEvent firstDown, MotionEvent firstUp, MotionEvent secondDown){            if (secondDown.getEventTime() - firstUp.getEventTime() > DOUBLE_TAP_TIMEOUT) {                return false;            }                    int deltaX =(int) firstUp.getX() - (int)secondDown.getX();            int deltaY =(int) firstUp.getY()- (int)secondDown.getY();                         return deltaX * deltaX + deltaY * deltaY < 10000;        }