Android判断是否在主线程

下面三个方法都可以判断当前线程是否在主线程

1public boolean isMainThread() {    return Looper.getMainLooper() == Looper.myLooper();}2public boolean isMainThread() {    return Looper.getMainLooper().getThread() == Thread.currentThread();}3public boolean isMainThread() {    return Looper.getMainLooper().getThread().getId() == Thread.currentThread().getId();}