在接android SDK的时候有时候为了方便debug调试查看,通过Toast输出相关信息,实际上这个是在子线程中输出的,在logcat里查看有如下报错java.lang.RuntimeException: Can't toast on a thread that has not called Looper.prepare()。解决办法为先调用Looper.prepare();再调用Toast.makeText().show();最后再调用Looper.loop();