Unable to add window -- token null is not valid

如果在 onCreate 中创建该问题，就会报如上异常

【如果activity已经finish掉了。在handlerMessage中调用的时候 也会报异常】

解决办法：在onCreate中执行：

mHandler.sendEmptyMessageDelayed(SHOWWINDOW, 200); private Handler mHandler = new Handler() { public void handleMessage(Message msg) { switch (msg.what) { case SHOWWINDOW: popupWindow = new PopupWindow(popView, LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT); popupWindow.showAtLocation(popView, Gravity.BOTTOM, 0, 0); Log.debug(TAG, "init popupWindow and showing!"); break; case ClOSEWINDOW: if (popupWindow != null) { popupWindow.dismiss(); } Log.debug(TAG, "close popupWindow and destory!"); break; } } };