PopupWindow實現點擊外部不消失

  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);