【木棉花】：Service核心技术精要直播之学习笔记（上） 原创 精华

<?xml version="1.0" encoding="utf-8"?>
<DirectionalLayout
    xmlns:ohos="http://schemas.huawei.com/res/ohos"
    ohos:height="match_parent"
    ohos:width="match_parent"
    ohos:alignment="center"
    ohos:background_element="$graphic:background_ability_main"
    >

  <Button
      ohos:id="$+id:btn_start"
      ohos:height="match_content"
      ohos:width="match_parent"
      ohos:text="启动本地设备的Service"
      ohos:text_color="#000000"
      ohos:background_element="$graphic:background_button"
      ohos:left_margin="30vp"
      ohos:right_margin="30vp"
      ohos:top_margin="30vp"
      ohos:bottom_margin="30vp"
      ohos:top_padding="10vp"
      ohos:bottom_padding="10vp"
      ohos:auto_font_size="true"
      />

  <Button
      ohos:id="$+id:btn_stop"
      ohos:height="match_content"
      ohos:width="match_parent"
      ohos:text="停止本地设备的Service"
      ohos:text_color="#000000"
      ohos:background_element="$graphic:background_button"
      ohos:left_margin="30vp"
      ohos:right_margin="30vp"
      ohos:top_margin="30vp"
      ohos:bottom_margin="30vp"
      ohos:top_padding="10vp"
      ohos:bottom_padding="10vp"
      ohos:auto_font_size="true"
      />
</DirectionalLayout>
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public class ServiceAbility extends Ability {
    private static final HiLogLabel LABEL_LOG = new HiLogLabel(3, 0xD001100, "Demo");
    private Player player=new Player(this);
    @Override
    public void onStart(Intent intent) {
        HiLog.info(LABEL_LOG, "onStart()被调用了");
        super.onStart(intent);

        EventRunner eventRunner = EventRunner.create(true);
        EventHandler eventHandler = new EventHandler(eventRunner);
        eventHandler.postTask(new Runnable() {
            @Override
            public void run() {
                try {
                    RawFileDescriptor rawFileDescriptor = getResourceManager()
                            .getRawFileEntry("resources/rawfile/test.mp3")
                            .openRawFileDescriptor();
                    Source source = new Source(rawFileDescriptor.getFileDescriptor(),
                            rawFileDescriptor.getStartPosition(),
                            rawFileDescriptor.getFileSize());
                    player.setSource(source);
                    player.prepare();
                    player.play();

                }catch(IOException e){
                    e.printStackTrace();
                }
            }
        });
    }

    @Override
    public void onCommand(Intent intent, boolean restart, int startId) {
        HiLog.info(LABEL_LOG, "onCommand()被调用了，第%{public}d次后被启动",startId);
    }

    @Override
    public void onBackground() {
        super.onBackground();
        HiLog.info(LABEL_LOG, "onBackground()被调用了");
    }

    @Override
    public void onStop() {
        super.onStop();
        HiLog.info(LABEL_LOG, "onStop()被调用了");

        if(player.isNowPlaying()){
            player.stop();
            player.release();
        }
    }
}
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public class MainAbilitySlice extends AbilitySlice {
    @Override
    public void onStart(Intent intent) {
        super.onStart(intent);
        super.setUIContent(ResourceTable.Layout_ability_main);

        Intent serviceIntent = new Intent();
        Operation serviceOperation = new Intent.OperationBuilder()
                .withDeviceId("")
                .withBundleName(getBundleName())
                .withAbilityName(ServiceAbility.class.getName())
                .build();
        serviceIntent.setOperation(serviceOperation);

        Button btnStart = (Button)findComponentById(ResourceTable.Id_btn_start);
        btnStart.setClickedListener(component -> {
            startAbility(serviceIntent);
        });

        Button btnStop = (Button)findComponentById(ResourceTable.Id_btn_stop);
        btnStop.setClickedListener(component -> {
            stopAbility(serviceIntent);
        });
    }
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"reqPermissions": [
      {
        "name": "ohos.permission.GET_DISTRIBUTED_DEVICE_INFO"
      },
      {
        "name": "ohos.permission.DISTRIBUTED_DEVICE_STATE_CHANGE"
      },
      {
        "name": "ohos.permission.GET_BUNDLE_INFO"
      },
      {
        "name": "ohos.permission.DISTRIBUTED_DATASYNC"
      }
    ]
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public class MainAbility extends Ability {
    @Override
    public void onStart(Intent intent) {
        super.onStart(intent);
        super.setMainRoute(MainAbilitySlice.class.getName());

        String[] permissions = { "ohos.permission.DISTRIBUTED_DATASYNC"};
        List<String> canRequestPermissions = new ArrayList<>();
        for(String permission:permissions){
            if(verifySelfPermission(permission)!= IBundleManager.PERMISSION_GRANTED){
                if(canRequestPermission(permission)){
                    canRequestPermissions.add(permission);
                }
            }
        }
        requestPermissionsFromUser(canRequestPermissions.toArray(new String[0]),0);
    }
}
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public class DeviceUtils {
    public static List<String> getOnlineDeviceIdList(){
        List<DeviceInfo> onlineDeviceInfoList =
                DeviceManager.getDeviceList(DeviceInfo.FLAG_GET_ONLINE_DEVICE);
        if(onlineDeviceInfoList == null || onlineDeviceInfoList.isEmpty()){
            return null;
        }
        List<String> onlineDeviceIdList = new ArrayList<>(onlineDeviceInfoList.size());
        onlineDeviceInfoList.forEach(onlineDeviceInfo -> {
            onlineDeviceIdList.add(onlineDeviceInfo.getDeviceId());
        });
        return onlineDeviceIdList;
    }
}
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public class MainAbilitySlice extends AbilitySlice {
    @Override
    public void onStart(Intent intent) {
        super.onStart(intent);
        super.setUIContent(ResourceTable.Layout_ability_main);

        Intent remoteIntent = new Intent();

        List<String> onlineDeviceIdList = DeviceUtils.getOnlineDeviceIdList();
        if(onlineDeviceIdList != null || !onlineDeviceIdList.isEmpty()){
            String remoteTargetDeviceId = onlineDeviceIdList.get(0);
            Operation serviceOperation = new Intent.OperationBuilder()
                    .withDeviceId(remoteTargetDeviceId)
                    .withBundleName(getBundleName())
                    .withAbilityName(ServiceAbility.class.getName())
                    .withFlags(Intent.FLAG_ABILITYSLICE_MULTI_DEVICE)
                    .build();
            remoteIntent.setOperation(serviceOperation);
        }

        Button btnStart = (Button)findComponentById(ResourceTable.Id_btn_start);
        btnStart.setClickedListener(component -> {
            startAbility(remoteIntent);
        });

        Button btnStop = (Button)findComponentById(ResourceTable.Id_btn_stop);
        btnStop.setClickedListener(component -> {
            stopAbility(remoteIntent);
        });
    }

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