// ignore some codes
final Looper me = myLooper();
if (me == null) {
?throw new RuntimeException("No Looper; Looper.prepare() wasn't called on this thread.");
}
final MessageQueue queue = me.mQueue;
// ignore some codes
看了些Android源碼微饥，看到很多這種情況吝岭，當(dāng)他們想用一個(gè)變量時(shí)，不是直接去用牙勘，而是換一個(gè)臨時(shí)變量并且用 final 修飾论泛。這是為什么呢揩尸？會(huì)提高性能嗎？
