The content of the adapter has changed but ListView did not receive a notification.

java.lang.IllegalStateException: The content of the adapter has changed but ListView did not receive a notification. Make sure the content of your adapter is not modified from a background thread, but only from the UI thread. Make sure your adapter calls notifyDataSetChanged() when its content changes.出现此错误的原因是，adapter的数据改变了但是没有调用adapter的notifyDataSetChanged()方法通知数据已改变造成的。