半夜三更不小心看了一个公众号。
不小心发现了这个Lifecycle...

Lifecycle-Aware 思想是Google官方提出来的概念：赋予普通类自动感知生命周期的能力。
Lifecycle实现的一个重要目的，是实现Android的与Activity和Fragment生命周期相关的逻辑控制进一步的解耦。

优化一：当Activity进入onDestroy时，自动取消网络请求返回
优化二：自动将网络请求时机提前到View渲染之前，提高页面打开速度
优化三：MVP改进，让Presenter和View自动bind/unBind

用法很简单

maven

allprojects {
    repositories {
        maven { url 'https://maven.google.com' }  //添加此行
        jcenter()
    }
}

    //For Lifecycles, LiveData, and ViewModel
    compile "android.arch.lifecycle:runtime:1.0.3"
    compile "android.arch.lifecycle:extensions:1.0.0"
    annotationProcessor "android.arch.lifecycle:compiler:1.0.0"

    //For Room
    compile "android.arch.persistence.room:runtime:1.0.0"
    annotationProcessor "android.arch.persistence.room:compiler:1.0.0"

public class HttpRequest implements LifecycleObserver {

    public HttpRequest() {
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_ANY)
    public void onAny() {
        Log.i("Tongson", "ON_ANY");
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_CREATE)
    public void onCreate() {
        Log.i("Tongson", "ON_CREATE");
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_START)
    public void onStart() {
        Log.i("Tongson", "ON_START");
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_RESUME)
    public void onResume() {
        Log.i("Tongson", "ON_RESUME");
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_PAUSE)
    public void onPause() {
        Log.i("Tongson", "ON_PAUSE");
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_STOP)
    public void onStop() {
        Log.i("Tongson", "ON_STOP");
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_DESTROY)
    public void onDestroy() {
        Log.i("Tongson", "onDestroy");
    }
}

        HttpRequest httpRequest = new HttpRequest();

        getLifecycle().addObserver(httpRequest);

源码：
https://chaosleong.github.io/2017/05/27/How-Lifecycle-aware-Components-actually-works/

https://code.tutsplus.com/tutorials/google-io-aftermath-building-lifecycle-aware-components--cms-28930

https://developer.android.com/topic/libraries/architecture/index.html
https://developer.android.com/topic/libraries/architecture/lifecycle.html
https://developer.android.com/topic/libraries/architecture/livedata.html
https://developer.android.com/topic/libraries/architecture/viewmodel.html