用Activity的onTouchEvent方法实现监听手指上下左右滑动

    float x1 = 0;    float x2 = 0;    float y1 = 0;    float y2 = 0;    int move=100;//移动距离  View.OnTouchListener onTouch=new View.OnTouchListener() {        @Override        public boolean onTouch(View v, MotionEvent event) {            if(event.getAction() == MotionEvent.ACTION_DOWN) {//当手指按下的时候                x1 = event.getX();                y1 = event.getY();            }            if(event.getAction() == MotionEvent.ACTION_UP) {//当手指离开的时候                x2 = event.getX();                y2 = event.getY();                if (y1 - y2 > move && (y1 - y2) > (x1 - x2) && (y1 - y2) > (x2 - x1)) {                    Toast.makeText(MainActivity.this, "向上滑", Toast.LENGTH_SHORT).show();                } else if (y2 - y1 > move && (y2 - y1) > (x1 - x2) && (y2 - y1) > (x2 - x1)) {                    Toast.makeText(MainActivity.this, "向下滑", Toast.LENGTH_SHORT).show();                } else if (x1 - x2 > move) {                    Toast.makeText(MainActivity.this, "向左滑", Toast.LENGTH_SHORT).show();                } else if (x2 - x1 > move) {                    Toast.makeText(MainActivity.this, "向右滑", Toast.LENGTH_SHORT).show();                }            }            return true;        }    };