LifeCycle-02-解耦service与组件------

我们知道，拥有生命周期概念的组件，除了Activity和Fragment，还有一个非常重要的组件是Service。

为了方便我们对Service生命周期的监听，Android提供了一个名为LifecycleService的类，该类继承自Service，并实现LifecycleOwner接口。

由于LifecycleService存在于扩展包中，所以，首先我们需要在app的build.gradle文件中添加依赖：

implementation 'android.arch.lifecycle:extensions:1.1.1'

该例子有四个文件

MyObserver.class

//获取位置信息的一种监听
public class MyObserver implements LifecycleObserver {

    Context context;

    //把service传进来
    public MyObserver(Context context) {
        this.context = context;
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_CREATE)
    private void startGetLocation() {
        Toast.makeText(context.getApplicationContext(), "服务开启", Toast.LENGTH_SHORT).show();
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_DESTROY)
    private void stopGetLocation(){
        Toast.makeText(context.getApplicationContext(), "服务关闭", Toast.LENGTH_SHORT).show();
    }
}

MyService.class

//别忘了去清单中注册service奥   application中
/*
*    
         
            
         
     
* */
public class MyService extends LifecycleService{

    public MyService() {
        Log.e("ning",getClass().getName());
        MyObserver myObserver = new MyObserver(this);
        getLifecycle().addObserver(myObserver);
    }

}

MainActivity.class

//lifecycle就是监听activity或者fragment的生命周期的

public class MainActivity extends AppCompatActivity {

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

    public void startGps(View view){
        startService(new Intent(this,MyService.class));
    }

    public void stopGps(View view){
        stopService(new Intent(this,MyService.class));
    }

}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/button"
        android:layout_width="141dp"
        android:layout_height="59dp"
        android:layout_marginTop="196dp"
        android:layout_marginBottom="145dp"
        android:text="开始"
        android:onClick="startGps"
        app:layout_constraintBottom_toTopOf="@+id/button2"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/button2"
        android:layout_width="137dp"
        android:layout_height="59dp"
        android:layout_marginBottom="272dp"
        android:text="结束"
        android:onClick="stopGps"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.492"
        app:layout_constraintStart_toStartOf="parent" />

androidx.constraintlayout.widget.ConstraintLayout>

jetpack-01-LifeCycle

LifeCycle-02-解耦service与组件------

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