错误：can't toast on a thread that has not called looper.prepare()

https://*.com/questions/3875184/cant-create-handler-inside-thread-that-has-not-called-looper-prepare

1 activity.runOnUiThread(new Runnable() {
2   public void run() {
3     Toast.makeText(activity, "Hello", Toast.LENGTH_SHORT).show();
4   }
5 });