android的popupwindow点击返回按钮关闭

今天想实现点击Popupwindow的外边不消失，点击返回键popupwindow自动关闭的效果，网上找了找，发现没有完整的，零碎的而且不准确，于是自己琢磨了一下，试了试效果。以下是实现效果的代码

[java]
View keyboardView = LayoutInflater.from(activity).inflate(R.layout.random_keyboard, null);
popupWindow = new PopupWindow(keyboardView,LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT,false);
//设置点击窗口外边窗口消失
popupWindow.setOutsideTouchable(false);
   // 设置此参数获得焦点，否则无法点击
popupWindow.setFocusable(true);

// popupWindow.setBackgroundDrawable(new BitmapDrawable()); //comment by danielinbiti,如果添加了这行，那么标注1和标注2那两行不用加，加上这行的效果是点popupwindow的外边也能关闭
keyboardView.setFocusable(true);//comment by danielinbiti,设置view能够接听事件，标注1
keyboardView.setFocusableInTouchMode(true); //comment by danielinbiti,设置view能够接听事件标注2
keyboardView.setOnKeyListener(new OnKeyListener(){
    @Override
    public boolean onKey(View arg0, int arg1, KeyEvent arg2) {
            if (arg1 == KeyEvent.KEYCODE_BACK){
            if(popupWindow != null) {
                close();
                }
            }
             return false;
    }
});

View keyboardView = LayoutInflater.from(activity).inflate(R.layout.random_keyboard, null);
popupWindow = new PopupWindow(keyboardView,LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT,false);
//设置点击窗口外边窗口消失
popupWindow.setOutsideTouchable(false);
   // 设置此参数获得焦点，否则无法点击
popupWindow.setFocusable(true);

// popupWindow.setBackgroundDrawable(new BitmapDrawable()); //comment by danielinbiti,如果添加了这行，那么标注1和标注2那两行不用加，加上这行的效果是点popupwindow的外边也能关闭
keyboardView.setFocusable(true);//comment by danielinbiti,设置view能够接听事件，标注1
keyboardView.setFocusableInTouchMode(true); //comment by danielinbiti,设置view能够接听事件标注2
keyboardView.setOnKeyListener(new OnKeyListener(){
@Override
public boolean onKey(View arg0, int arg1, KeyEvent arg2) {
       if (arg1 == KeyEvent.KEYCODE_BACK){
        if(popupWindow != null) {
         close();
        }
       }
        return false;
}
});

补充：移动开发 , Android ,