Can't create handler inside thread that has not called Looper.prepare()
Crach描述:在子线程中调用了这句:Toast.makeText(this,"",Toast.LENGTH_LONG).show();然后就崩溃了:java.lang.RuntimeException:Can'tcreatehandlerinsidethreadthathasnotcalledLooper.prepare()//atandroid.os.Handler.(Handler.java