PopupWindow实现点击外部不消失

  View contentView = LayoutInflater.from(MainActivity.this).inflate(R.layout.alert_ip, null);
        final PopupWindow popupWindow = new PopupWindow(contentView,
                LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT, true);
             popupWindow.setTouchable(true);
        popupWindow.setBackgroundDrawable(new BitmapDrawable());
        popupWindow.setOutsideTouchable(true);

        popupWindow.setTouchInterceptor(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                return true;
            }
        });
        popupWindow.showAtLocation(getWindow().getDecorView(), Gravity.CENTER, 0, 0);