Android的UI组件不是线程安全的，不应该在worker线程操纵UI

Additionally, the Andoid UI toolkit is not thread-safe. So, you must not manipulate your UI from a worker thread—you must do all manipulation to your user interface from the UI thread. Thus, there are simply two rules to Android's single thread model:Do not block the UI thread
Do not access the Android UI toolkit from outside the UI thread

UI组件不是线程安全的，所以不应该在worker线程操纵UI。