Android jetPack 组件摸索学习->Lifecycle

俺啥也不晓得,莫得基础.看着怪新鲜的,就zun备试一哈

首先是这样

生命周期

可以看到 是通过注解 的

---

public class MyObserver implements LifecycleObserver  {
    @OnLifecycleEvent(Lifecycle.Event.ON_ANY)
    public void OnAnyListener() {
        System.out.println("ON_ANY");

    }

    @OnLifecycleEvent(Lifecycle.Event.ON_CREATE)
    public void OnCreateListener() {
        System.out.println("ON_CREATE");
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_START)
    public void OnStartListener() {
        System.out.println("ON_START");
    }
    
    @OnLifecycleEvent(Lifecycle.Event.ON_RESUME)
    public void OnResumeListener() {
        System.out.println("ON_RESUME");
    }
    
    
    @OnLifecycleEvent(Lifecycle.Event.ON_PAUSE)
    public void OnPauseListener() {
        System.out.println("ON_PAUSE");
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_STOP)
    public void OnStopListener() {
        System.out.println("ON_STOP");
    }
    
    @OnLifecycleEvent(Lifecycle.Event.ON_DESTROY)
    public void OnDestoryListener() {
        System.out.println("ON_DESTROY");
    }

}

---

然而当我点进这个枚举

然后是这样

@SuppressWarnings("WeakerAccess")
    public enum Event {
        /**
         * Constant for onCreate event of the {@link LifecycleOwner}.
         */
        ON_CREATE,
        /**
         * Constant for onStart event of the {@link LifecycleOwner}.
         */
        ON_START,
        /**
         * Constant for onResume event of the {@link LifecycleOwner}.
         */
        ON_RESUME,
        /**
         * Constant for onPause event of the {@link LifecycleOwner}.
         */
        ON_PAUSE,
        /**
         * Constant for onStop event of the {@link LifecycleOwner}.
         */
        ON_STOP,
        /**
         * Constant for onDestroy event of the {@link LifecycleOwner}.
         */
        ON_DESTROY,
        /**
         * An {@link Event Event} constant that can be used to match all events.
         */
        ON_ANY
    }

---

接着就那样

看的出来,也是需要先绑定的,然后关联

public class MainActivity extends AppCompatActivity  implements LifecycleOwner {

    private LifecycleRegistry lifecycleRegistry;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        lifecycleRegistry = new LifecycleRegistry(this);
        lifecycleRegistry.addObserver(new MyObserver());
        lifecycleRegistry.markState(Lifecycle.State.CREATED);
    }

    @Override
    protected void onStart() {
        super.onStart();
        lifecycleRegistry.markState(Lifecycle.State.STARTED);

    }

    @Override
    protected void onResume() {
        super.onResume();
        lifecycleRegistry.markState(Lifecycle.State.RESUMED);
    }


    @Override
    protected void onPause() {
        super.onPause();
    }


    @Override
    protected void onStop() {
        super.onStop();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        lifecycleRegistry.markState(Lifecycle.State.DESTROYED);
    }


    @Override
    public Lifecycle getLifecycle() {
        return lifecycleRegistry;
    }
}

---

然而他的第二个枚举

明显少几个

public enum State {
        /**
         * Destroyed state for a LifecycleOwner. After this event, this Lifecycle will not dispatch
         * any more events. For instance, for an {@link android.app.Activity}, this state is reached
         * <b>right before</b> Activity's {@link android.app.Activity#onDestroy() onDestroy} call.
         */
        DESTROYED,

        /**
         * Initialized state for a LifecycleOwner. For an {@link android.app.Activity}, this is
         * the state when it is constructed but has not received
         * {@link android.app.Activity#onCreate(android.os.Bundle) onCreate} yet.
         */
        INITIALIZED,

        /**
         * Created state for a LifecycleOwner. For an {@link android.app.Activity}, this state
         * is reached in two cases:
         * <ul>
         *     <li>after {@link android.app.Activity#onCreate(android.os.Bundle) onCreate} call;
         *     <li><b>right before</b> {@link android.app.Activity#onStop() onStop} call.
         * </ul>
         */
        CREATED,

        /**
         * Started state for a LifecycleOwner. For an {@link android.app.Activity}, this state
         * is reached in two cases:
         * <ul>
         *     <li>after {@link android.app.Activity#onStart() onStart} call;
         *     <li><b>right before</b> {@link android.app.Activity#onPause() onPause} call.
         * </ul>
         */
        STARTED,

        /**
         * Resumed state for a LifecycleOwner. For an {@link android.app.Activity}, this state
         * is reached after {@link android.app.Activity#onResume() onResume} is called.
         */
        RESUMED;

        /**
         * Compares if this State is greater or equal to the given {@code state}.
         *
         * @param state State to compare with
         * @return true if this State is greater or equal to the given {@code state}
         */
        public boolean isAtLeast(@NonNull State state) {
            return compareTo(state) >= 0;
        }
    }

---

只开启Ac 打印结果  长的那些是 我退出了Ac

2019-03-07 11:16:22.225 21985-21985/? I/System.out: ON_CREATE
2019-03-07 11:16:22.225 21985-21985/? I/System.out: ON_ANY
2019-03-07 11:16:22.227 21985-21985/? I/System.out: ON_START
2019-03-07 11:16:22.227 21985-21985/? I/System.out: ON_ANY
2019-03-07 11:16:22.230 21985-21985/? I/System.out: ON_RESUME
2019-03-07 11:16:22.230 21985-21985/? I/System.out: ON_ANY
2019-03-07 11:16:36.976 21985-21985/com.as.lifecycle I/System.out: ON_PAUSE
2019-03-07 11:16:36.977 21985-21985/com.as.lifecycle I/System.out: ON_ANY
2019-03-07 11:16:37.213 21985-21985/com.as.lifecycle I/System.out: ON_STOP
2019-03-07 11:16:37.213 21985-21985/com.as.lifecycle I/System.out: ON_ANY
2019-03-07 11:16:37.214 21985-21985/com.as.lifecycle I/System.out: ON_DESTROY
2019-03-07 11:16:37.214 21985-21985/com.as.lifecycle I/System.out: ON_ANY

推测:这可能是观察者模式 给封了一个库 专门提供 组件 之间进行  沟通的 

ON_ANY  会在每个方法之后在走一遍   然而  pause stop 是自动的 没有在Activty里mark 怪不得;俩个枚举少参数

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