popupwindow 的问题
popupwindow 显示后，当触屏点击非popupwindow显示区域，如何让这个popupwindow窗口消失？请帮忙，谢谢！！
[最优解释]

  if (pop == null) {
                  pop = new PopupWindow(menuview, screenWidth/2, screenHeight/2, true); 
                  pop.setBackgroundDrawable(this.getResources().getDrawable(R.drawable.select_device_bg));
                  pop.setTouchInterceptor(new OnTouchListener(){

public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub

if(event.getAction() == MotionEvent.ACTION_OUTSIDE)
{
pop.dismiss();
}
return false;
}
                  
                  });
                //  pop.setAnimationStyle(R.style.PopupAnimation); 
                  pop.setOutsideTouchable(true);  
                  pop.showAsDropDown(view, Gravity.CENTER_HORIZONTAL, 0);
                  pop.update();  
        } else {  
        if (pop.isShowing()) {
                  pop.dismiss();  
                  pop = null; 

[其他解释]
谢谢楼上。主要是没有设置setBackgroundDrawable，设置以后点击非PopupWindow就可以消失了。