private PopupWindow mPopupWindow;  //popup window 一般popuowindow 要都个显示view,本例子中view模拟菜单.
private View mMenu;                //popup window 里的view

mMenu.setFocusableInTouchMode(true);
mMenu.setOnKeyListener(this);
mMenu.setOnTouchListener(this);

mPopupWindow.setFocusable(true);
mPopupWindow.setOutsideTouchable(true);

@Override
    public boolean onKey(View v, int keyCode, KeyEvent event) {
        // TODO Auto-generated method stub
        switch (keyCode) {
        case KeyEvent.KEYCODE_BACK:
        case KeyEvent.KEYCODE_MENU:
            if (mPopupWindow != null && mPopupWindow.isShowing()) {
                mPopupWindow.dismiss();
            }
            break;
        }
        return true;
    }
    @Override
    public boolean onTouch(View v, MotionEvent event) {
        // TODO Auto-generated method stub
        mPopupWindow.dismiss();
        return false;
    }

　　　　　/*
         * setBackgroundDrawable很重要,没有这个函数 back键和menu键关闭popwindow 很麻烦,
         * 有了它以后,就不用为popwindow内的控件分别设置setOnKeyListener和setOnTouchListener了
         * 可以同时支持back,menu键和点popwindow外面关闭popwindow,
         */
        mPopupWindow.setBackgroundDrawable(new ColorDrawable(-00000));
        mPopupWindow.setFocusable(true);
        mPopupWindow.setOutsideTouchable(true);