Fragment(Activity同理，我们 本文以Fragment为例，下同)：实现了LifecycleOwner接口，这意味着Fragment对象持有生命周期对象（Lifecycle），并可以通过Lifecycle getLifecycle()方法获取内部的Lifecycle对象：

Fragment：LifecycleOwnerSSC采集器修复，需要请搜索【大神源码论坛】客服企娥3393756370 V信17061863513，public class Fragment implements xxx, LifecycleOwner {

//...省略其他

LifecycleRegistry mLifecycleRegistry = new LifecycleRegistry(this);

@Overridepublic Lifecycle getLifecycle() {    return mLifecycleRegistry;}

}

public interface LifecycleOwner {

可以看到，实现的getLifecycle()方法，实际上返回的是 LifecycleRegistry 对象，LifecycleRegistry对象实际上继承了 Lifecycle，这个下文再讲。

持有Lifecycle有什么作用呢？实际上在Fragment对应的生命周期内，都会发送对应的生命周期事件给内部的 LifecycleRegistry对象处理：

public class Fragment implements xxx, LifecycleOwner {

//...void performCreate(Bundle savedInstanceState) { onCreate(savedInstanceState); //1.先执行生命周期方法//...省略代码//2.生命周期事件分发mLifecycleRegistry.handleLifecycleEvent(Lifecycle.Event.ON_CREATE);}

void performStart() {    onStart();    //...    mLifecycleRegistry.handleLifecycleEvent(Lifecycle.Event.ON_START);}void performResume() {     onResume();    //...    mLifecycleRegistry.handleLifecycleEvent(Lifecycle.Event.ON_RESUME);}void performPause() {    //3.注意，调用顺序变了    mLifecycleRegistry.handleLifecycleEvent(Lifecycle.Event.ON_PAUSE);    //...    onPause();}void performStop() {   mLifecycleRegistry.handleLifecycleEvent(Lifecycle.Event.ON_STOP);    //...    onStop();}void performDestroy() {    mLifecycleRegistry.handleLifecycleEvent(Lifecycle.Event.ON_DESTROY);    //...    onDestroy();}

}

随着Fragment不同走到不同的生命周期，除了暴露给我们的生命周期方法onCreate/onStart/…./onDestroy等，同时，Fragment内部的Lifecycle对象（就是mLifecycleRegistry）还将生命周期对应的事件作为参数传给了 handleLifecycleEvent() 方法。