目录：
1、跨设备启动FA、跨设备迁移、回迁
2、跨设备连接Service
3、更多文章
![鸿蒙软总线跨设备访问该怎么玩——小总结]()
重点撸代码：
1、跨设备启动FA、跨设备迁移、回迁
（1）权限
ohos.permission.DISTRIBUTED_DEVICE_STATE_CHANGE：用于允许监听分布式组网内的设备状态变化。
ohos.permission.GET_DISTRIBUTED_DEVICE_INFO：用于允许获取分布式组网内的设备列表和设备信息。
ohos.permission.GET_BUNDLE_INFO：用于查询其他应用的信息。
ohos.permission.DISTRIBUTED_DATASYNC：用于允许不同设备间的数据交换。
"reqPermissions": [
{"name": "ohos.permission.DISTRIBUTED_DATASYNC"},
{"name": "ohos.permission.DISTRIBUTED_DEVICE_STATE_CHANGE"},
{"name": "ohos.permission.GET_DISTRIBUTED_DEVICE_INFO" },
{"name": "ohos.permission.GET_BUNDLE_INFO"}
]
//主动申明，要多设备协同，让用户选择允许还是禁止
requestPermissionsFromUser(new String[]{"ohos.permission.DISTRIBUTED_DATASYNC"}, 0);
（2）界面：ability_main.xml
<?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:orientation="vertical">
<Button
ohos:id="$+id:main_start_fa_btn"
ohos:height="match_content"
ohos:width="300vp"
ohos:text="1.启动远程设备的FA"
ohos:text_size="20fp"
ohos:text_color="#ffffff"
ohos:background_element="$graphic:button_bg"
ohos:layout_alignment="horizontal_center"
ohos:top_padding="8vp"
ohos:bottom_padding="8vp"
ohos:left_padding="40vp"
ohos:right_padding="40vp"
ohos:top_margin="20vp"
/>
<Button
ohos:id="$+id:main_migration_btn"
ohos:height="match_content"
ohos:width="300vp"
ohos:text="2.迁移到远程设备"
ohos:text_size="20fp"
ohos:text_color="#ffffff"
ohos:background_element="$graphic:button_bg"
ohos:layout_alignment="horizontal_center"
ohos:top_padding="8vp"
ohos:bottom_padding="8vp"
ohos:left_padding="40vp"
ohos:right_padding="40vp"
ohos:top_margin="20vp"
/>
</DirectionalLayout>
button_bg.xml
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:ohos="http://schemas.huawei.com/res/ohos"
ohos:shape="rectangle">
<solid ohos:color="#007DFF"/>
<corners ohos:radius="40"/>
</shape>
另外我们需要的Page Abiltiy：MigrationAbility、RemoveAbility
MainAbilitySlice:
public class MainAbilitySlice extends AbilitySlice {
private Button mainStartFABtn,mainMigrationBtn;
@Override
public void onStart(Intent intent) {
super.onStart(intent);
super.setUIContent(ResourceTable.Layout_ability_main);
mainStartFABtn = (Button)findComponentById(ResourceTable.Id_main_start_fa_btn);
mainMigrationBtn = (Button)findComponentById(ResourceTable.Id_main_migration_btn);
mainStartFABtn.setClickedListener(mClickListener);
mainMigrationBtn.setClickedListener(mClickListener);
}
private Component.ClickedListener mClickListener = new Component.ClickedListener() {
@Override
public void onClick(Component component) {
int compoentId = component.getId();
switch (compoentId){
case ResourceTable.Id_main_start_fa_btn:
//点击后跨设备打开Fa
//第一种写法
Intent intent = new Intent();
Operation op = new Intent.OperationBuilder()
.withDeviceId(Common.getOnLineDeviceId())
.withBundleName("com.ybzy.demo")
.withAbilityName("com.ybzy.demo.RemoveAbility")
.withFlags(Intent.FLAG_ABILITYSLICE_MULTI_DEVICE)
.build();
intent.setOperation(op);
intent.setParam("msg","我夸设备把你这个FA拉起来了！");
startAbility(intent);
//第二钟写法
intent.setElement(new ElementName(Common.getOnLineDeviceId()
,"com.ybzy.demo","com.ybzy.demo.RemoveAbility"));
intent.setFlags(Intent.FLAG_ABILITYSLICE_MULTI_DEVICE);
intent.setParam("msg","我夸设备把你这个FA拉起来了！");
startAbility(intent);
break;
case ResourceTable.Id_main_migration_btn:
//点击后进入要迁移的Ability页面
Intent migrationIntent = new Intent();
migrationIntent.setElement(new ElementName("","com.ybzy.demo"
,"com.ybzy.demo.MigrationAbility"));
startAbility(migrationIntent);
break;
default:
break;
}
}
};
@Override
public void onActive() {
super.onActive();
}
@Override
public void onForeground(Intent intent) {
super.onForeground(intent);
}
}
ability_migration.xml
<?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:background_element="#00ffff"
ohos:orientation="vertical">
<Text
ohos:id="$+id:migration_text"
ohos:height="match_content"
ohos:width="250vp"
ohos:background_element="#0088bb"
ohos:layout_alignment="horizontal_center"
ohos:text="下面是一个可编辑的文本框"
ohos:text_size="50"
ohos:padding="5vp"
ohos:top_margin="30vp"
/>
<TextField
ohos:id="$+id:migration_textfield"
ohos:height="250vp"
ohos:width="250vp"
ohos:hint="请输入..."
ohos:layout_alignment="horizontal_center"
ohos:background_element="#ffffff"
ohos:text_color="#888888"
ohos:text_size="20fp"
ohos:padding="5vp"
/>
<Button
ohos:id="$+id:migration_migration_btn"
ohos:height="match_content"
ohos:width="match_content"
ohos:text="点击迁移"
ohos:text_size="20fp"
ohos:text_color="#ffffff"
ohos:background_element="$graphic:button_bg"
ohos:top_padding="8vp"
ohos:bottom_padding="8vp"
ohos:left_padding="50vp"
ohos:right_padding="50vp"
ohos:layout_alignment="horizontal_center"
ohos:top_margin="30vp"
/>
<Button
ohos:id="$+id:migration_migration_back_btn"
ohos:height="match_content"
ohos:width="match_content"
ohos:text="点击迁移回来"
ohos:text_size="20fp"
ohos:text_color="#ffffff"
ohos:background_element="$graphic:button_bg"
ohos:top_padding="8vp"
ohos:bottom_padding="8vp"
ohos:left_padding="50vp"
ohos:right_padding="50vp"
ohos:layout_alignment="horizontal_center"
ohos:top_margin="30vp"
/>
</DirectionalLayout>
RemoveAbility...把接收到的值显示到页面就行，setText()
（3）工具类
public class Common{
public static String getDeviceId(){
List<DeviceInfo> deviceList = DeviceManager.getDeviceList(DeviceInfo.FLAG_GET_ONLINE_DEVICE);
if(deviceList.isEmpty()){
return null;
}
int deviceNum = deviceList.size();
List<String> deviceIds = new ArrayList<>(deviceNum);
List<String> deviceNames = new ArrayList<>(deviceNum);
deviceList.forEach((device)->{
deviceIds.add(device.getDeviceId());
deviceNames.add(device.getDeviceName());
});
//我们这里的实验环境，就两部手机，组件还没讲
//我就直接使用deviceIds的第一个元素，做为启动远程设备的目标id
String devcieIdStr = deviceIds.get(0);
return devcieIdStr;
}
public static void myShowTip(Context context,String msg){
//提示框的核心组件文本
Text text = new Text(context);
text.setWidth(MATCH_CONTENT);
text.setHeight(MATCH_CONTENT);
text.setTextSize(16, Text.TextSizeType.FP);
text.setText(msg);
text.setPadding(30,20,30,20);
text.setMultipleLine(true);
text.setMarginLeft(30);
text.setMarginRight(30);
text.setTextColor(Color.WHITE);
text.setTextAlignment(TextAlignment.CENTER);
//给上面的文本设置一个背景样式
ShapeElement style = new ShapeElement();
style.setShape(ShapeElement.RECTANGLE);
style.setRgbColor(new RgbColor(77,77,77));
style.setCornerRadius(15);
text.setBackground(style);
//构建存放上面的text的布局
DirectionalLayout mainLayout = new DirectionalLayout(context);
mainLayout.setWidth(MATCH_PARENT);
mainLayout.setHeight(MATCH_CONTENT);
mainLayout.setAlignment(LayoutAlignment.CENTER);
mainLayout.addComponent(text);
//最后要让上面的组件绑定dialog
ToastDialog toastDialog = new ToastDialog(context);
toastDialog.setSize(MATCH_PARENT,MATCH_CONTENT);
toastDialog.setDuration(1500);
toastDialog.setAutoClosable(true);
toastDialog.setTransparent(true);
toastDialog.setAlignment(LayoutAlignment.CENTER);
toastDialog.setComponent((Component) mainLayout);
toastDialog.show();
}
}
（4）实现功能
MigrationAbilitySlice：
public class MigrationAbilitySlice extends AbilitySlice implements IAbilityContinuation {
TextField migrationTextField;
Button migrationMigrationBtn,migrationMigrationBackBtn;
String msg = "";
@Override
public void onStart(Intent intent) {
super.onStart(intent);
super.setUIContent(ResourceTable.Layout_ability_migration);
migrationTextField = (TextField)findComponentById(ResourceTable.Id_migration_textfield);
migrationTextField.setText(msg);
migrationMigrationBtn = (Button)findComponentById(ResourceTable.Id_migration_migration_btn);
migrationMigrationBtn.setClickedListener(component -> {
//1、要进行迁移的Ability实现接口 IAbilityContinuation，实现的方法返回值改成true
//2、要进行迁移的Ability下面关联的所有AbilitySlice都要实现接口 IAbilityContinuation，
// 实现的方法上处理数据
//3、进行迁移
String deviceId = Common.getOnLineDeviceId();
if(deviceId != null){
// continueAbility(deviceId);
continueAbilityReversibly(deviceId);
}
});
migrationMigrationBackBtn = (Button) findComponentById(ResourceTable
.Id_migration_migration_back_btn);
migrationMigrationBackBtn.setClickedListener(component -> {
reverseContinueAbility();
});
}
@Override
public void onActive() {
super.onActive();
}
@Override
public void onForeground(Intent intent) {
super.onForeground(intent);
}
@Override
public boolean onStartContinuation() {
return true;
}
@Override
public boolean onSaveData(IntentParams intentParams) {
intentParams.setParam("msg",migrationTextField.getText());
return true;
}
@Override
public boolean onRestoreData(IntentParams intentParams) {
msg = intentParams.getParam("msg").toString();
// getUITaskDispatcher().asyncDispatch(() -> {
// migrationTextField.setText(intentParams.getParam("msg").toString());
// });
return true;
}
@Override
public void onCompleteContinuation(int i) {
}
}
2、跨设备连接Service
启动远程设备Service的代码示例如下：
添加按钮：
<Button
ohos:id="$+id:main_start_removeService_btn"
ohos:height="match_content"
ohos:width="300vp"
ohos:text="远程启动ServiceAbility"
ohos:text_size="20fp"
ohos:text_color="#ffffff"
ohos:background_element="$graphic:button_bg"
ohos:layout_alignment="horizontal_center"
ohos:top_padding="8vp"
ohos:bottom_padding="8vp"
ohos:left_padding="40vp"
ohos:right_padding="40vp"
ohos:top_margin="20vp"
/>
<Button
ohos:id="$+id:main_stop_removeService_btn"
ohos:height="match_content"
ohos:width="300vp"
ohos:text="远程关闭ServiceAbility"
ohos:text_size="20fp"
ohos:text_color="#ffffff"
ohos:background_element="$graphic:button_bg"
ohos:layout_alignment="horizontal_center"
ohos:top_padding="8vp"
ohos:bottom_padding="8vp"
ohos:left_padding="40vp"
ohos:right_padding="40vp"
ohos:top_margin="20vp"
/>
新建RemoteServiceAbility：
public class RemoteServiceAbility extends Ability {
private static final HiLogLabel LABEL_LOG = new HiLogLabel(3, 0xD001100, "Demo");
private Source sVideoSource;
private Player sPlayer;
@Override
public void onStart(Intent intent) {
HiLog.error(LABEL_LOG, "RmoteServiceAbility::onStart");
super.onStart(intent);
Common.myShowTip(this,"remote onstart");
sPlayer = new Player(RemoteServiceAbility.this);
new PlayerThread().start();
}
class PlayerThread extends Thread {
@Override
public void run() {
try {
File mp3FilePath = getExternalFilesDir(Environment.DIRECTORY_MUSIC);
if (!mp3FilePath.exists()) {
mp3FilePath.mkdirs();
}
File mp3File = new File(mp3FilePath.getAbsolutePath() + "/" + "bj.mp3");
Resource res = getResourceManager()
.getRawFileEntry("resources/rawfile/bj.mp3").openRawFile();
byte[] buf = new byte[4096];
int count = 0;
FileOutputStream fos = new FileOutputStream(mp3File);
while ((count = res.read(buf)) != -1) {
fos.write(buf, 0, count);
}
FileDescriptor fileDescriptor = new FileInputStream(mp3File).getFD();
sVideoSource = new Source(fileDescriptor);
sPlayer.setSource(sVideoSource);
sPlayer.prepare();
sPlayer.setVolume(0.3f);
sPlayer.enableSingleLooping(true);
sPlayer.play();
} catch (IOException e) {
e.printStackTrace();
}
}
}
@Override
public void onStop() {
super.onStop();
Common.myShowTip(RemoteServiceAbility.this,"remote onStop");
sPlayer.stop();
}
@Override
public IRemoteObject onConnect(Intent intent) {
return null;
}
@Override
public void onDisconnect(Intent intent) {
}
}
启动：
case ResourceTable.Id_main_start_remoteService_btn:
Common.myShowTip(MainAbilitySlice.this,deviceId);
Intent startRemoteServiceIntent = new Intent();
startRemoteServiceIntent.setElement(new ElementName(
deviceId,
"com.ybzy.demo",
"com.ybzy.demo.RemoteServiceAbility"
));
startRemoteServiceIntent.setFlags(Intent.FLAG_ABILITYSLICE_MULTI_DEVICE);
startAbility(startRemoteServiceIntent);
break;
关闭远程设备Service：
case ResourceTable.Id_main_stop_remoteService_btn:
Common.myShowTip(MainAbilitySlice.this,deviceId);
Intent stopRemoteServiceIntent = new Intent();
stopRemoteServiceIntent.setElement(new ElementName(
deviceId,
"com.ybzy.demo",
"com.ybzy.demo.RemoteServiceAbility"
));
stopRemoteServiceIntent.setFlags(Intent.FLAG_ABILITYSLICE_MULTI_DEVICE);
stopAbility(stopRemoteServiceIntent);
break;
仅通过启动和停止Service Ability两种方式对Service进行调度无法应对需长期交互的场景，
简单地说，信息就是只能去，回不来！
因此，分布式任务调度平台向开发者提供了跨设备Service连接及断开连接的能力。
链接上了，信息可去可回！
链接是使用connectAbility()方法，需要传入目标Service的Intent与接口IAbilityConnection的实例对象。
接口IAbilityConnection提供了两个方法供开发者实现：
（1）onAbilityConnectDone()用来处理连接的回调。
（2）onAbilityDisconnectDone()用来处理断开连接的回调。
我们可以在onAbilityConnectDone()中获取管理链接的代理，进一步为了使用该代理跨设备调度Service，
开发者需要在本地及远端分别实现对外接口一致的代理，这个接口是IRemoteBroker。
添加按钮：
<Button
ohos:id="$+id:main_connect_remoteService_btn"
ohos:height="match_content"
ohos:width="300vp"
ohos:text="远程链接ServiceAbility"
ohos:text_size="20fp"
ohos:text_color="#ffffff"
ohos:background_element="$graphic:button_bg"
ohos:layout_alignment="horizontal_center"
ohos:top_padding="8vp"
ohos:bottom_padding="8vp"
ohos:left_padding="40vp"
ohos:right_padding="40vp"
ohos:top_margin="20vp"
/>
<Button
ohos:id="$+id:main_use_remoteService_btn"
ohos:height="match_content"
ohos:width="300vp"
ohos:text="使用远程ServiceAbility"
ohos:text_size="20fp"
ohos:text_color="#ffffff"
ohos:background_element="$graphic:button_bg"
ohos:layout_alignment="horizontal_center"
ohos:top_padding="8vp"
ohos:bottom_padding="8vp"
ohos:left_padding="40vp"
ohos:right_padding="40vp"
ohos:top_margin="20vp"
/>
<Button
ohos:id="$+id:main_disconnect_remoteService_btn"
ohos:height="match_content"
ohos:width="300vp"
ohos:text="远程断开ServiceAbility"
ohos:text_size="20fp"
ohos:text_color="#ffffff"
ohos:background_element="$graphic:button_bg"
ohos:layout_alignment="horizontal_center"
ohos:top_padding="8vp"
ohos:bottom_padding="8vp"
ohos:left_padding="40vp"
ohos:right_padding="40vp"
ohos:top_margin="20vp"
/>
发起连接的本地侧的代理示例如下：
public class MyRemoteProxy implements IRemoteBroker {
//IRemoteBroker:获取远程代理对象的持有者
private static final int ERR_OK = 0;
//COMMAND_PLUS表示有效消息进行通信的约定的标记，MIN_TRANSACTION_ID是这个标记可以用的最小值：1
private static final int COMMAND_PLUS = IRemoteObject.MIN_TRANSACTION_ID;
//IRemoteObject:此接口
// 可用于查询或获取接口描述符、
// 添加或删除死亡通知、
// 将对象状态转储到特定文件以及发送消息。
private final IRemoteObject remote;
public MyRemoteProxy(IRemoteObject remote) {
this.remote = remote;
}
@Override
public IRemoteObject asObject() {//获取远程代理对象的方法
return remote;
}
public int plus(int a,int b) throws RemoteException {
//MessageParcel:这个类提供了读写对象、接口标记、文件描述符和大数据的方法。
MessageParcel data = MessageParcel.obtain();
//obtain()创建索引为0的空MessageParcel对象
MessageParcel reply = MessageParcel.obtain();
//MessageOption:定义与sendRequest一起发送消息的选项。
// option不同的取值，决定采用同步或异步方式跨设备调用Service
// 这个例子我们需要同步获取对端Service执行加法运算后的结果，同步模式调用sendRequest接口，即MessageOption.TF_SYNC
// 对应的是异步：TF_ASYNC
MessageOption option = new MessageOption(MessageOption.TF_SYNC);
data.writeInt(a);
data.writeInt(b);
try {
remote.sendRequest(COMMAND_PLUS, data, reply, option);
//第1个参数：约定通信双方确定的消息标记。
//第2个参数：发送到对等端侧的数据包裹MessageParcel对象。
//第3个参数：对等端侧返回的数据包裹MessageParcel对象。
//第4个参数：设置发送消息，用同步还是异步模式。
int ec = reply.readInt(); //返回通信成不成功，约定的标记ERR_OK
if (ec != ERR_OK) {
throw new RemoteException();
}
int result = reply.readInt();
return result;
} catch (RemoteException e) {
throw new RemoteException();
} finally {
data.reclaim(); //reclaim()清除不再使用的MessageParcel对象。
reply.reclaim();
}
}
}
等待连接的远端侧的代理示例如下：
public class MyRemote extends RemoteObject implements IRemoteBroker{
private static final int ERR_OK = 0;
private static final int ERROR = -1;
private static final int COMMAND_PLUS = IRemoteObject.MIN_TRANSACTION_ID;
public MyRemote() {
super("MyService_Remote");
}
@Override
public IRemoteObject asObject() {
return this;
}
@Override
public boolean onRemoteRequest(int code, MessageParcel data, MessageParcel reply, MessageOption option) {
if (code != COMMAND_PLUS) {
reply.writeInt(ERROR);
return false;
}
int value1 = data.readInt();
int value2 = data.readInt();
int sum = value1 + value2;
reply.writeInt(ERR_OK);
reply.writeInt(sum);
return true;
}
}
等待连接侧还需要作如下修改：
// 绑定前面定义的代理，实例化出发起链接侧需要的代理
private MyRemote remote = new MyRemote();
@Override
public IRemoteObject onConnect(Intent intent) {
//链接成功的时候，给发起链接侧返回去
return remote.asObject();
}
完成上述步骤后，可以通过点击事件实现连接、利用连接关系控制PA以及断开连接等行为，代码示例如下：
private MyRemoteProxy mProxy = null;
// 创建连接回调实例
private IAbilityConnection conn = new IAbilityConnection() {
// 连接到Service的回调
@Override
public void onAbilityConnectDone(ElementName elementName, IRemoteObject iRemoteObject, int resultCode) {
// 在这里开发者可以拿到服务端传过来IRemoteObject对象，从中解析出服务端传过来的信息
mProxy = new MyRemoteProxy(iRemoteObject);
UIUtils.showTip(MainAbilitySlice.this,"拿到remoteObject：" + mProxy);
}
// 意外断开连接才会回调
@Override
public void onAbilityDisconnectDone(ElementName elementName, int resultCode) {
}
};
// 连接远程
case ResourceTable.Id_main_connect_remoteService_btn:
//1、实现连接的本地侧的代理
//2、实现等待连接的远端侧的代理
//3、修改等待连接侧的Service
//4、在本地(发起链接侧)获取远端(被链接侧)返回过来的链接代理，创建链接后的回调函数
//5、实现链接，通过代理对象使用Service的服务
if (deviceId != null) {
Intent connectServiceIntent = new Intent();
connectServiceIntent.setElement(new ElementName(
deviceId,
"com.ybzy.demo",
"com.ybzy.demo.RemoteServiceAbility"
));
connectServiceIntent.setFlags(Intent.FLAG_ABILITYSLICE_MULTI_DEVICE);
connectAbility(connectServiceIntent, iAbilityConnection);
}
break;
// 链接后使用
case ResourceTable.Id_main_use_remoteService_btn:
if (mProxy != null) {
int ret = -1;
try {
ret = mProxy.plus(10, 20);
} catch (RemoteException e) {
e.printStackTrace();
}
Common.myShowTip(MainAbilitySlice.this, "获取的结果：" + ret);
}
break;
// 用完断开
case ResourceTable.Id_main_disconnect_remoteService_btn:
disconnectAbility(iAbilityConnection);
break;
作者：zhonghongfa
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