Popupwindow 触摸外部 消失

PopupWindow popupWindow = new PopupWindow(view,
        LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT, false);//focusable为false

// 如果不设置PopupWindow的背景，无论是点击外部区域还是Back键都无法dismiss弹框
// 我觉得这里是API的一个bug
popupWindow.setBackgroundDrawable(getResources().getDrawable(
        R.drawable.bgconfig_w));
popupWindow.setOutsideTouchable(true);

依据PopupWindow的源代码：

/**
 * 
Controls whether the pop-up will be informed of touch events outside
 * of its window.  This only makes sense for pop-ups that are touchable
 * but not focusable, which means touches outside of the window will
 * be delivered to the window behind.  The default is false.
 *
 * 
If the popup is showing, calling this method will take effect only
 * the next time the popup is shown or through a manual call to one of
 * the {@link #update()} methods.
 *
 * @param touchable true if the popup should receive outside
 * touch events, false otherwise
 *
 * @see #isOutsideTouchable()
 * @see #isShowing()
 * @see #update()
 */
public void setOutsideTouchable(boolean touchable) {
    mOutsideTouchable = touchable;
}