如果沒有看過占位式插件化框架—Activity通信的請先看這篇文章，因為這篇文章是在它的基礎(chǔ)上寫的。
思考：插件p.apk中PluginActivity怎么啟動和關(guān)閉同是插件包中的TestService？

通過占位式插件化框架—Activity通信應(yīng)該可以想到怎么實現(xiàn)：

• 先寫一個標(biāo)準(zhǔn)服務(wù)的接口ServiceInterface
• 在插件中寫一個服務(wù)的基類BaseService，BaseService繼承Service和實現(xiàn)ServiceInterface。創(chuàng)建TestService類,TestService類繼承BaseService。
• 在主apk中創(chuàng)建一個服務(wù)的代理類(ProxyService)，用于調(diào)用插件服務(wù)的方法。

public interface ServiceInterface {
    /**
     * 把宿主(app)的環(huán)境  給  插件
     *
     * @param appService
     */
    void insertAppContext(Service appService);
    void onCreate();
    int onStartCommand(Intent intent, int flags, int startId);
    void onDestroy();
    boolean onUnbind(Intent intent);
    IBinder onBind(Intent intent);
}

public class BaseService extends Service implements ServiceInterface {
    public Service appService;
    @Override
    public void insertAppContext(Service appService) {
        this.appService = appService;
    }
    @Override
    public void onCreate() {
    }
    @SuppressLint("WrongConstant")
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        return 0;
    }
    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }
    @Override
    public void onDestroy() {
    }
}

public class TestService extends BaseService {

    public static Boolean Run = true;
    @Override
    public void onCreate() {
        super.onCreate();
    }
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Toast.makeText(appService, "啟動插件TestService", Toast.LENGTH_LONG).show();
        new Thread(new Runnable() {
            @Override
            public void run() {
                while (Run) {
                    try {
                        Thread.sleep(1000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    } finally {
                        Log.e("migill", "插件里面的服務(wù)TestService開啟了一個線程 正在執(zhí)行中...");
                    }
                }
                Log.e("migill", "插件里面的服務(wù)TestService開啟的線程執(zhí)行結(jié)束");
            }
        }).start();
        return super.onStartCommand(intent, flags, startId);
    }
    @Override
    public void onDestroy() {
        Toast.makeText(appService, "關(guān)閉插件TestService", Toast.LENGTH_LONG).show();
        Run = false;
        Log.e("migill", "插件里面的服務(wù)TestService執(zhí)行onDestroy()");
        super.onDestroy();
    }
}

TestService的onStartCommand()方法開啟了一個線程，在調(diào)用onDestroy()的時候線程的run()方法就會執(zhí)行結(jié)束。
接下來就是要增加啟動和關(guān)閉服務(wù)的按鈕，點擊后要調(diào)用宿主的啟動和關(guān)閉服務(wù)的方法。

public class BaseActivity extends Activity implements ActivityInterface {
    .......
    @Override
    public ComponentName startService(Intent service) {
        Intent intentNew = new Intent();
        Log.e("migill", "BaseActivity startService className:" + service.getComponent().getClassName());
        intentNew.putExtra("className", service.getComponent().getClassName());
        return appActivity.startService(intentNew);
    }

    @Override
    public boolean stopService(Intent name) {
        Intent intentNew = new Intent();
        Log.e("migill", "BaseActivity stopService className:" + name.getComponent().getClassName());
        intentNew.putExtra("className", name.getComponent().getClassName());
        return appActivity.stopService(intentNew);
    }
}

在BaseActivity中增加啟動和關(guān)閉服務(wù)的方法。startService()和stopService()兩個方法都是調(diào)用宿主中的方法。

public class PluginActivity extends BaseActivity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_plugin);//執(zhí)行的是BaseActivity中的setContentView方法
        Log.e("migill", "我是插件PluginActivity");
        .......
        findViewById(R.id.bt_start_service).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startService(new Intent(appActivity, TestService.class));
            }
        });

        findViewById(R.id.bt_stop_service).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                stopService(new Intent(appActivity, TestService.class));
            }
        });
    }
}

點擊啟動服務(wù)的按鈕，調(diào)用的是BaseActivity中的startService()。
點擊停止服務(wù)的按鈕，調(diào)用的是BaseActivity中的stopService()。
編譯apk,重命名為p.apk,并放入 /storage/emulated/0/Android/data/com.migill.pluginproject/files/這個目錄下。

public class ProxyActivity extends Activity {
......
    @Override
    public ComponentName startService(Intent service) {
        String className = service.getStringExtra("className");
        Log.e("migill", "ProxyActivity startService className : " + className);
        Intent intent = new Intent(this, ProxyService.class);
        intent.putExtra("className", className);
        return super.startService(intent);
    }

    @Override
    public boolean stopService(Intent name) {
        String className = name.getStringExtra("className");
        Log.e("migill", "ProxyActivity stopService className : " + className);
        Intent intent = new Intent(this, ProxyService.class);
        intent.putExtra("className", className);
        return super.stopService(intent);
    }
}

這兩個方法都是開啟和關(guān)閉代理的服務(wù)。

public class ProxyService extends Service {
    ServiceInterface serviceInterface;
    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }
    @Override
    public void onCreate() {
        super.onCreate();
        Log.e("migill", "ProxyService onCreate()");
    }
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        String className = intent.getStringExtra("className");
        Log.e("migill", "ProxyService onStartCommand() className:" + className);

        try {
            Class mTestServiceClass = PluginManager.getInstance(this).getClassLoader().loadClass(className);
            Object mTestService = mTestServiceClass.newInstance();
            serviceInterface = (ServiceInterface) mTestService;
            //注入組件環(huán)境
            serviceInterface.insertAppContext(this);
            serviceInterface.onStartCommand(intent, flags, startId);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return super.onStartCommand(intent, flags, startId);
    }
    @Override
    public void onDestroy() {
        Log.e("migill", "ProxyService onDestroy()");
        if (serviceInterface != null)
            serviceInterface.onDestroy();
        super.onDestroy();
    }
}

啟動ProxyService服務(wù)的時候會走onStartCommand()生命周期方法，它就會根據(jù)全類名實例化對象，并調(diào)用serviceInterface.onStartCommand()。
關(guān)閉ProxyService服務(wù)的時候會走onDestroy()方法，并調(diào)用serviceInterface.onDestroy()。