点击空白，键盘退出

@Override
    public boolean onTouchEvent(MotionEvent event) {
        InputMethodManager manager = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
        if (event.getAction() == MotionEvent.ACTION_DOWN) {
            if (getCurrentFocus() != null
                    && getCurrentFocus().getWindowToken() != null) {
                manager.hideSoftInputFromWindow(getCurrentFocus()
                        .getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);
            }
        }
        return super.onTouchEvent(event);
    }