32.Service服务 组件的学习

压缩包

test2.zip

一、认识Service

服务在后台默默的运行，是不可见的

二、startService和bindService的生命周期图

1.startService：服务由自身或客户端停止

2.bindService：通过调用unbindService()来解除所有客户端绑定

三、startService与生命周期

1.布局activity_main3.xml文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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=".Main3Activity"
    android:orientation="vertical">
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="startService"
        android:text="STARTSERVICE"
        android:textSize="30sp"
        tools:ignore="OnClick" />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="stopService"
        android:text="STOPSERVICE"
        android:textSize="30sp"
        tools:ignore="OnClick" />
</LinearLayout>

2.MyService服务类文件代码

package com.example.test;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.util.Log;
import androidx.annotation.Nullable;
public class MyService extends Service {
    private final static String TAG=MyService.class.getSimpleName();
    @Override
    public void onCreate() {
        super.onCreate();
        Log.d(TAG,"onCreate()...");
    }
    @Override
    public void onStart(Intent intent, int startId) {
        super.onStart(intent, startId);
        Log.d(TAG,"onStart()...");
    }
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.d(TAG,"onStartCommand()...");
        return super.onStartCommand(intent, flags, startId);
    }
    @Override
    public void onDestroy() {
        Log.d(TAG,"onDestroy()...");
        super.onDestroy();
    }
    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        Log.d(TAG,"onBind()...");
        return null;
    }
//    @Override
//    public boolean onUnbind(Intent intent) {
//        Log.d(TAG,"onUnbind()...");
//        return super.onUnbind(intent);
//    }
}

3.Main3Activity文件代码

package com.example.test;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
public class Main3Activity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main3);
    }
    public void startActivity(View view) {
        Intent intent = new Intent();
        intent.setClass(Main3Activity.this,MActivity.class);
        startActivity(intent);
    }
    //启动服务
    public void startService(View view) {
        startService(new Intent(this,MyService.class));
    }
    //停止服务
    public void stopService(View view) {
        stopService(new Intent(this,MyService.class));
    }
}

4.清单文件中注册服务类组件权限

5.执行代码，点击启动服务按钮

6.点击停止服务按钮

四、bindService与生命周期

1.bind和unbind按钮的实现

2.构建绑定个解绑的桥梁

3.布局activity_main3.xml文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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=".Main3Activity"
    android:orientation="vertical">
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="startService"
        android:text="STARTSERVICE"
        android:textSize="30sp" />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="stopService"
        android:text="STOPSERVICE"
        android:textSize="30sp" />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="bindService"
        android:text="BINDSERVICE"
        android:textSize="30sp"
        android:layout_marginTop="100dp"/>
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="unBindService"
        android:text="UNBINDSERVICE"
        android:textSize="30sp" />
</LinearLayout>

4.Main3Activity文件代码

package com.example.test;
import androidx.appcompat.app.AppCompatActivity;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;
import android.view.View;
public class Main3Activity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main3);
    }
    public void startActivity(View view) {
        Intent intent = new Intent();
        intent.setClass(Main3Activity.this,MActivity.class);
        startActivity(intent);
    }
    //启动服务
    public void startService(View view) {
        startService(new Intent(this,MyService.class));
    }
    //停止服务
    public void stopService(View view) {
        stopService(new Intent(this,MyService.class));
    }
    public void bindService(View view) {
        bindService(new Intent(this,MyService.class),connecton, Context.BIND_AUTO_CREATE);
    }
    public void unBindService(View view) {
        unbindService(connecton);
    }
    //MainActivity与MyService的桥梁
    private ServiceConnection connecton=new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
        }
        @Override
        public void onServiceDisconnected(ComponentName name) {
        }
    };
    //一般的写法，当此Activity被销毁的时候，自动解雇服务
    @Override
    protected void onDestroy() {
        super.onDestroy();
        unbindService(connecton);
    }
}

5.绑定之后实现的方法（onCreate()->onBind()）

6.解绑之后执行的方法（onUnbind()->onDestroy()）

7.返回之后销毁服务（onUnbind()->onDestroy()）