华为Harmony鸿蒙开发笔记四：ServiceAbility使用_鸿蒙serviceability

按照上图创建ServiceAbility，会自动生成带有生命周期的类和配置文件：

package com.example.serviceabilitydemo;
 
import ohos.aafwk.ability.Ability;
import ohos.aafwk.content.Intent;
import ohos.rpc.IRemoteObject;
import ohos.hiviewdfx.HiLog;
import ohos.hiviewdfx.HiLogLabel;
 
public class ServiceAbility extends Ability {
    private static final HiLogLabel LABEL_LOG = new HiLogLabel(3, 0xD001100, "Demo");
 
    @Override
    public void onStart(Intent intent) {
        HiLog.error(LABEL_LOG, "ServiceAbility::onStart");
        super.onStart(intent);
    }
 
    @Override
    public void onBackground() {
        super.onBackground();
        HiLog.info(LABEL_LOG, "ServiceAbility::onBackground");
    }
 
    @Override
    public void onStop() {
        super.onStop();
        HiLog.info(LABEL_LOG, "ServiceAbility::onStop");
    }
 
    @Override
    public void onCommand(Intent intent, boolean restart, int startId) {
    }
 
    @Override
    public IRemoteObject onConnect(Intent intent) {
        return null;
    }
 
    @Override
    public void onDisconnect(Intent intent) {
    }
}

      {
        "name": "com.example.serviceabilitydemo.ServiceAbility",
        "icon": "$media:icon",
        "description": "$string:serviceability_description",
        "type": "service",
        "visible": true
      }

启动ServiceAbility跟跳转PageAbility的代码一模一样：

            btnStartAbility.setClickedListener(new Component.ClickedListener() {
                @Override
                public void onClick(Component component) {
                    Intent intent = new Intent();
                    Operation operation = new Intent.OperationBuilder()
                            .withDeviceId("")
                            .withBundleName("com.example.serviceabilitydemo")
                            .withAbilityName("com.example.serviceabilitydemo.ServiceAbility")
                            .build();
                    intent.setOperation(operation);
                    startAbility(intent);
                }
            });

从启动到结束的生命周期：

12-28 21:49:00.645 3798-3798/com.example.serviceabilitydemo E 01100/MyLog: ServiceAbility::onStart
12-28 21:49:00.646 3798-3798/com.example.serviceabilitydemo E 01100/MyLog: ServiceAbility::onCommand
12-28 21:49:13.521 3800-3800/? E 01100/MyLog: ServiceAbility::onStart
12-28 21:49:13.524 3800-3800/? E 01100/MyLog: ServiceAbility::onBackground
12-28 21:49:13.524 3800-3800/com.example.serviceabilitydemo E 01100/MyLog: ServiceAbility::onStop

onStart方法居然执行了两次，官方文档是这样的

由于我是用杀进程的方式停止Service的，于是我又试了试用stopAbility来停止Service：

        Button btnStartAbility= (Button) findComponentById(ResourceTable.Id_btn_start_service);
        if (btnStartAbility != null) {
            // 为按钮设置点击回调
            btnStartAbility.setClickedListener(new Component.ClickedListener() {
                @Override
                public void onClick(Component component) {
                    Intent intent = new Intent();
                    Operation operation = new Intent.OperationBuilder()
                            .withDeviceId("")
                            .withBundleName("com.example.serviceabilitydemo")
                            .withAbilityName("com.example.serviceabilitydemo.ServiceAbility")
                            .build();
                    intent.setOperation(operation);
                    startAbility(intent);
                }
            });
        }
        Button btnStopAbility= (Button) findComponentById(ResourceTable.Id_btn_stop_service);
        if (btnStopAbility != null) {
            // 为按钮设置点击回调
            btnStopAbility.setClickedListener(new Component.ClickedListener() {
                @Override
                public void onClick(Component component) {
                    Intent intent = new Intent();
                    Operation operation = new Intent.OperationBuilder()
                            .withDeviceId("")
                            .withBundleName("com.example.serviceabilitydemo")
                            .withAbilityName("com.example.serviceabilitydemo.ServiceAbility")
                            .build();
                    intent.setOperation(operation);
                    stopAbility(intent);
                }
            });
        }

这次是正常的：

12-28 21:55:12.115 28321-28321/com.example.serviceabilitydemo E 01100/MyLog: ServiceAbility::onStart
12-28 21:55:12.116 28321-28321/com.example.serviceabilitydemo E 01100/MyLog: ServiceAbility::onCommand
12-28 21:55:18.776 28321-28321/com.example.serviceabilitydemo E 01100/MyLog: ServiceAbility::onBackground
12-28 21:55:18.776 28321-28321/com.example.serviceabilitydemo E 01100/MyLog: ServiceAbility::onStop

不知道为什么杀进程会多执行一次onStart方法。

最后，连接ServiceAbility，先定义一个用来传递的类，这个类必须继承LocalRemoteObject：

package com.example.serviceabilitydemo;
 
import ohos.aafwk.ability.LocalRemoteObject;
 
public class MyRemoteObject extends LocalRemoteObject {
    private String msg;
    public MyRemoteObject() {
        super();
    }
 
    public MyRemoteObject(String msg) {
        super();
        this.msg = msg;
    }
 
    public String getMsg() {
        return msg;
    }
 
    public void setMsg(String msg) {
        this.msg = msg;
    }
}

连接：

        Button connStopAbility= (Button) findComponentById(ResourceTable.Id_btn_conn_service);
        if (connStopAbility != null) {
            // 为按钮设置点击回调
            connStopAbility.setClickedListener(new Component.ClickedListener() {
                @Override
                public void onClick(Component component) {
                    Intent intent = new Intent();
                    Operation operation = new Intent.OperationBuilder()
                            .withDeviceId("")
                            .withBundleName("com.example.serviceabilitydemo")
                            .withAbilityName("com.example.serviceabilitydemo.ServiceAbility")
                            .build();
                    intent.setOperation(operation);
                    // 连接Service
                    connectAbility(intent, connection);
                }
            });
        }

其中connection是实现了IAbilityConnection接口的内部类

    // 创建连接回调实例
    private IAbilityConnection connection = new IAbilityConnection() {
        // 连接到Service的回调
        @Override
        public void onAbilityConnectDone(ElementName elementName, IRemoteObject iRemoteObject, int resultCode) {
            // Client侧需要定义与Service侧相同的IRemoteObject实现类。
            // 开发者获取服务端传过来IRemoteObject对象，并从中解析出服务端传过来的信息。
            MyRemoteObject remoteObject=(MyRemoteObject)iRemoteObject;
            remoteObject.getMsg();
            HiLog.error(LABEL_LOG, "onAbilityConnectDone() msg="+remoteObject.getMsg());
        }
 
        // 断开与连接的回调
        @Override
        public void onAbilityDisconnectDone(ElementName elementName, int resultCode) {
        }
    };

Service中要在onConnect方法返回数据：

    @Override
    public IRemoteObject onConnect(Intent intent) {
        HiLog.error(LABEL_LOG, "ServiceAbility::onConnect");
        return new MyRemoteObject("我是从服务器端返回的消息");
    }

 

官方文档上还有这样一个流程：

 

但是我一旦执行连接ServiceAbility，就无法在执行停止ServiceAbility了，杀进程也不行。

Demo：https://download.csdn.net/download/y280903468/13973575