HarmonyOS 鸿蒙Next中实现消息传递

HarmonyOS 鸿蒙Next中实现消息传递

介绍

在HarmonyOS中，参考官方指导，其实你会发现在‘指南’和‘API参考’两个文档中，对消息传递使用的技术不是一对一的关系，那么今天这篇文章带你全面了解HarmonyOS 中的消息传递

概况

参照官方指导，我总结了两部分：1. 官方“指南”，即下图中的“Stage模型” 2. 总结的内容，即“消息事件”

开始

EventHub

这个其实是可以帮大家解决几个最常见的消息传递场景：1. UIAbility和其它 2.页面和其它 3. 组件和其它

官方指导

1. 订阅

this.context.eventHub.on(‘onConfigurationUpdate’, (data) => {
//订阅


});

2. 发送

let eventhub = this.context.eventHub;
eventhub.emit(‘onConfigurationUpdate’, config);

3. 解除订阅

this.context.eventHub.off(‘onConfigurationUpdate’)

CommonEvent

参照官方指南，其总称简写为CES(全称：Common Event Service），可以监听系统锁屏，时间变化，等等

1. 订阅

usual.event.TIME_TICK ： 系统公共事件

harvey.event.CUSTOM_1 ： 自定义事件

let subscribeInfo = {
events: [“usual.event.TIME_TICK”, ‘harvey.event.CUSTOM_1’]
}


// 1. 创建订阅者
commonEventManager.createSubscriber(subscribeInfo, (err, subscriber) => {
if (err) {
console.error(Failed to create subscriber. Code is ${err.code}, message is ${err.message});
return;
}
console.info(‘Succeeded in creating subscriber.’ + JSON.stringify(subscriber));


this.subscriberID = subscriber


// 2. 订阅事件回调
commonEventManager.subscribe(subscriber, (err, commonEventData) => {
if (err) {
console.error(Failed to subscribe common event. Code is ${err.code}, message is ${err.message});
return;
} else {
systemDateTime.getCurrentTime(false, (error, data) => {
this.mySubscriberInfo = data + ‘<=>’ + JSON.stringify(commonEventData, null, ‘\t’)
})
}
})
})

2. 发送

对于系统级别的公共事件， 三方应用无权发送公共事件（即，即使你发送了，也是不会被收到的）

但是你可以自定义自己的公共事件

commonEventManager.publish(‘harvey.event.CUSTOM_1’, option, (error) => {
console.log(JSON.stringify(error))
})

3. 解除订阅

解除时用的是订阅者ID

commonEventManager.unsubscribe(this.subscriberID);

Emitter

1. 订阅

必须要有eventId, 这个代表消息的唯一标识

let innerEvent = {
eventId: 1847
};


emitter.on(innerEvent, (eventData) => {
this.emitterData = process.tid + ’ ’ + JSON.stringify(eventData)
});

2. 发送

let eventData = {
data: {
‘count’: this.emitterCount++,
‘from’: ‘emitter’,
“content”: “c”,
“id”: 1,
}};
let innerEvent = {
eventId: 1847,
priority: emitter.EventPriority.HIGH
};
emitter.emit(innerEvent, eventData);

3. 解除订阅

emitter.off(1847)

Worker

1. 订阅

import worker from ‘@ohos.worker’;


let wk1 = new worker.ThreadWorker("/entry/ets/workers/Worker.ts")


wk1.onmessage = (msg) => {


}

2. 发送

a）从worker线程中发送

import worker, { ThreadWorkerGlobalScope, MessageEvents, ErrorEvent } from ‘@ohos.worker’;


var workerPort : ThreadWorkerGlobalScope = worker.workerPort;


workerPort.postMessage(
{
…
}
)

b) 从主线程中发送

wk1.dispatchEvent({type: ‘message’, timeStamp: 0})

3. 解除订阅

//第一种
wk1.off(‘message’)
//第二种
wk1.removeEventListener(‘message’)
//第三种：强制关闭线程
wk1…terminate()

TaskTool 和 Notification

总结

HarmonyOS是一个新系统，还是要实践才可能在真实的业务开发中灵活运用

-------------------------------------------------------------------------------------------------------------------------------

实践代码效果

Screenshot_20231208165412224.pngScreenshot_20231208165404339.pngScreenshot_20231208165416940.png

公共事件代码

import commonEventManager from ‘@ohos.commonEventManager’;
import systemDateTime from ‘@ohos.systemDateTime’;


/**



*/
@Entry
@Component
struct CommonEventIndex {


@State mySubscriberInfo: string = ‘下一分钟会更新的’


private subscriberID


@State count: number = 0


aboutToAppear() {


<span class="hljs-keyword">let</span> subscribeInfo = {
  events: [<span class="hljs-string">"usual.event.TIME_TICK"</span>, <span class="hljs-string">'harvey.event.CUSTOM_1'</span>]
}

<span class="hljs-comment">// 创建订阅者回调</span>
commonEventManager.createSubscriber(subscribeInfo, (err, subscriber) =&gt; {
  <span class="hljs-keyword">if</span> (err) {
    console.error(`Failed to create subscriber. Code is ${err.code}, message is ${err.message}`);
    <span class="hljs-keyword">return</span>;
  }
  console.info(<span class="hljs-string">'Succeeded in creating subscriber.'</span> + <span class="hljs-built_in">JSON</span>.stringify(subscriber));

  <span class="hljs-keyword">this</span>.subscriberID = subscriber

  <span class="hljs-comment">// 订阅公共事件回调</span>
  commonEventManager.subscribe(subscriber, (err, commonEventData) =&gt; {
    <span class="hljs-keyword">if</span> (err) {
      console.error(`Failed to subscribe common event. Code is ${err.code}, message is ${err.message}`);
      <span class="hljs-keyword">return</span>;
    } <span class="hljs-keyword">else</span> {
      systemDateTime.getCurrentTime(<span class="hljs-literal">false</span>, (error, data) =&gt; {
        <span class="hljs-keyword">this</span>.mySubscriberInfo = data + <span class="hljs-string">'&lt;=&gt;'</span> + <span class="hljs-built_in">JSON</span>.stringify(commonEventData, <span class="hljs-literal">null</span>, <span class="hljs-string">'\t'</span>)
      })
    }
  })
})
}


aboutToDisappear(){
commonEventManager.unsubscribe(this.subscriberID);
}


build() {


Column(){
  Text(<span class="hljs-keyword">this</span>.mySubscriberInfo)
    .width(<span class="hljs-string">'100%'</span>)
    .fontColor(Color.Black)
    .fontSize(<span class="hljs-number">20</span>)
    .textAlign(TextAlign.Center)

  Button(<span class="hljs-string">'发布自定义公共事件'</span>).onClick(()=&gt;{

    <span class="hljs-keyword">let</span> option = {
      code: <span class="hljs-number">0</span>,
      data: <span class="hljs-built_in">JSON</span>.stringify({<span class="hljs-string">'hello'</span>: <span class="hljs-string">'word'</span>}),
      isOrdered: <span class="hljs-literal">true</span>,
      <span class="hljs-comment">// isSticky: true, 仅限系统应用&amp;服务</span>
      parameters: {
        <span class="hljs-string">'who'</span>: <span class="hljs-string">'am i'</span>,
        <span class="hljs-string">'count'</span>: <span class="hljs-keyword">this</span>.count++
      }
    }

    commonEventManager.publish(<span class="hljs-string">'harvey.event.CUSTOM_1'</span>, option, (error) =&gt; {
      console.log(<span class="hljs-built_in">JSON</span>.stringify(error))
    })
  })
}.width(<span class="hljs-string">'100%'</span>).height(<span class="hljs-string">'100%'</span>)

.justifyContent(FlexAlign.Center)
.alignItems(HorizontalAlign.Center)
}


}
<button style="position: absolute; padding: 4px 8px 0px; cursor: pointer; top: 8px; right: 8px; font-size: 14px;">复制</button>

线程代码

import emitter from ‘@ohos.events.emitter’
import worker from ‘@ohos.worker’;
import process from ‘@ohos.process’;
import Prompt from ‘@system.prompt’;


/**


    

  • 依据官方指导，最多只能创建8个worker
    • 

  • 



*/
let wk1 = new worker.ThreadWorker("/entry/ets/workers/Worker.ts")
let wk2 = new worker.ThreadWorker("/entry/ets/workers/Worker2.ts")
let wk3 = new worker.ThreadWorker("/entry/ets/workers/Worker3.ts")
let wk4 = new worker.ThreadWorker("/entry/ets/workers/Worker4.ts")
let wk5 = new worker.ThreadWorker("/entry/ets/workers/Worker5.ts")
let wk6 = new worker.ThreadWorker("/entry/ets/workers/Worker6.ts")
let wk7 = new worker.ThreadWorker("/entry/ets/workers/Worker7.ts")
let wk8 = new worker.ThreadWorker("/entry/ets/workers/Worker8.ts")


@Entry
@Component
struct ThreadModelIndex {


@State emitterData: string = ‘’
emitterCount: number = 0


@State worker1Color: number = 0
@State worker2Color: number = 0
@State worker3Color: number = 0
@State worker4Color: number = 0
@State worker5Color: number = 0
@State worker6Color: number = 0
@State worker7Color: number = 0
@State worker8Color: number = 0


@State workerData: string = ‘’


workerTotal: number = 8;


async count() {
this.workerTotal–


<span class="hljs-keyword">if</span>(<span class="hljs-keyword">this</span>.workerTotal == <span class="hljs-number">0</span>){
  Prompt.showToast({message: <span class="hljs-string">'8个任务已完成'</span>})
}
}


aboutToDisappear(){
wk1.terminate()
wk2.terminate()
wk3.terminate()
wk4.terminate()
wk5.terminate()
wk6.terminate()
wk7.terminate()
wk8.terminate()
}


aboutToAppear() {


<span class="hljs-comment">// 处理来自worker线程的消息</span>
wk1.onmessage = <span class="hljs-function"><span class="hljs-keyword">function</span><span class="hljs-params">(message)</span> {</span>
  console.log(<span class="hljs-string">"message from worker: "</span> + <span class="hljs-built_in">JSON</span>.stringify(message))
}

wk1.onmessage = (msg) =&gt; {

  <span class="hljs-keyword">if</span>(msg &amp;&amp; msg.data){
    <span class="hljs-keyword">if</span>(msg.data.no == <span class="hljs-number">1</span>){
      <span class="hljs-keyword">this</span>.worker1Color = Color.Green
    } <span class="hljs-keyword">else</span> {
      <span class="hljs-keyword">this</span>.worker1Color = Color.Orange
    }
    <span class="hljs-keyword">this</span>.count()
  }

}

wk1.addEventListener(<span class="hljs-string">"message"</span>, (e)=&gt;{
  <span class="hljs-keyword">this</span>.workerData = <span class="hljs-built_in">JSON</span>.stringify(e)
  console.log(<span class="hljs-string">"message listener callback: "</span> + <span class="hljs-built_in">JSON</span>.stringify(e));
})

wk1.addEventListener(<span class="hljs-string">"WorkerTest"</span>, (e)=&gt;{
  <span class="hljs-keyword">this</span>.workerData = <span class="hljs-built_in">JSON</span>.stringify(e)
})

wk2.onmessage = (msg) =&gt; {
  <span class="hljs-keyword">if</span>(msg.data.no == <span class="hljs-number">2</span>){
    <span class="hljs-keyword">this</span>.worker2Color = Color.Green
  } <span class="hljs-keyword">else</span> {
    <span class="hljs-keyword">this</span>.worker2Color = Color.Orange
  }
  <span class="hljs-keyword">this</span>.count()
}
wk3.onmessage = (msg) =&gt; {
  <span class="hljs-keyword">if</span>(msg.data.no == <span class="hljs-number">3</span>){
    <span class="hljs-keyword">this</span>.worker3Color = Color.Green
  } <span class="hljs-keyword">else</span> {
    <span class="hljs-keyword">this</span>.worker3Color = Color.Orange
  }
  <span class="hljs-keyword">this</span>.count()
}
wk4.onmessage = (msg) =&gt; {
  <span class="hljs-keyword">if</span>(msg.data.no == <span class="hljs-number">4</span>){
    <span class="hljs-keyword">this</span>.worker4Color = Color.Green
  } <span class="hljs-keyword">else</span> {
    <span class="hljs-keyword">this</span>.worker4Color = Color.Orange
  }
  <span class="hljs-keyword">this</span>.count()
}
wk5.onmessage = (msg) =&gt; {
  <span class="hljs-keyword">if</span>(msg.data.no == <span class="hljs-number">5</span>){
    <span class="hljs-keyword">this</span>.worker5Color = Color.Green
  } <span class="hljs-keyword">else</span> {
    <span class="hljs-keyword">this</span>.worker5Color = Color.Orange
  }
  <span class="hljs-keyword">this</span>.count()
}
wk6.onmessage = (msg) =&gt; {
  <span class="hljs-keyword">if</span>(msg.data.no == <span class="hljs-number">6</span>){
    <span class="hljs-keyword">this</span>.worker6Color = Color.Green
  } <span class="hljs-keyword">else</span> {
    <span class="hljs-keyword">this</span>.worker6Color = Color.Orange
  }
  <span class="hljs-keyword">this</span>.count()
}
wk7.onmessage = (msg) =&gt; {
  <span class="hljs-keyword">if</span>(msg.data.no == <span class="hljs-number">7</span>){
    <span class="hljs-keyword">this</span>.worker7Color = Color.Green
  } <span class="hljs-keyword">else</span> {
    <span class="hljs-keyword">this</span>.worker7Color = Color.Orange
  }
  <span class="hljs-keyword">this</span>.count()
}
wk8.onmessage = (msg) =&gt; {
  <span class="hljs-keyword">if</span>(msg.data.no == <span class="hljs-number">8</span>){
    <span class="hljs-keyword">this</span>.worker8Color = Color.Green
  } <span class="hljs-keyword">else</span> {
    <span class="hljs-keyword">this</span>.worker8Color = Color.Orange
  }
  <span class="hljs-keyword">this</span>.count()
}

<span class="hljs-keyword">let</span> innerEvent = {
  eventId: <span class="hljs-number">1847</span>
};

emitter.on(innerEvent, (eventData) =&gt; {
   <span class="hljs-keyword">this</span>.emitterData = process.tid + <span class="hljs-string">' '</span> + <span class="hljs-built_in">JSON</span>.stringify(eventData)
});
}


build() {


Column(){
  Text(<span class="hljs-string">'主线程ID: '</span> + process.tid)

  Text(<span class="hljs-keyword">this</span>.emitterData).fontSize(<span class="hljs-number">25</span>).textAlign(TextAlign.Center).margin({top: <span class="hljs-number">20</span>})

  Text(<span class="hljs-string">'发送 emitter 消息'</span>)
    .fontSize(<span class="hljs-number">20</span>)
    .fontColor(Color.White)
    .borderRadius(<span class="hljs-string">'12vp'</span>)
    .backgroundColor(Color.Blue)
    .padding(<span class="hljs-number">10</span>)
    .stateStyles({
      focused: {
        .backgroundColor(Color.Green)
      },
      pressed: {
        .backgroundColor(Color.Green)
      },
      normal: {
        .backgroundColor(Color.Blue)
      }
    })
    .onClick(()=&gt;{

        <span class="hljs-keyword">let</span> eventData = {
          data: {
            <span class="hljs-string">'count'</span>: <span class="hljs-keyword">this</span>.emitterCount++,
            <span class="hljs-string">'from'</span>: <span class="hljs-string">'emitter'</span>,
            <span class="hljs-string">"content"</span>: <span class="hljs-string">"c"</span>,
            <span class="hljs-string">"id"</span>: <span class="hljs-number">1</span>,
          }};
        <span class="hljs-keyword">let</span> innerEvent = {
          eventId: <span class="hljs-number">1847</span>,
          priority: emitter.EventPriority.HIGH
        };
        emitter.emit(innerEvent, eventData);

    })
    .margin({top: <span class="hljs-number">20</span>})

  Row(){
    Text(<span class="hljs-string">'1'</span>).fontSize(<span class="hljs-number">40</span>).backgroundColor(<span class="hljs-keyword">this</span>.worker1Color).fontColor(Color.White)
    Text(<span class="hljs-string">'2'</span>).fontSize(<span class="hljs-number">40</span>).backgroundColor(<span class="hljs-keyword">this</span>.worker2Color).fontColor(Color.White)
    Text(<span class="hljs-string">'3'</span>).fontSize(<span class="hljs-number">40</span>).backgroundColor(<span class="hljs-keyword">this</span>.worker3Color).fontColor(Color.White)
    Text(<span class="hljs-string">'4'</span>).fontSize(<span class="hljs-number">40</span>).backgroundColor(<span class="hljs-keyword">this</span>.worker4Color).fontColor(Color.White)
    Text(<span class="hljs-string">'5'</span>).fontSize(<span class="hljs-number">40</span>).backgroundColor(<span class="hljs-keyword">this</span>.worker5Color).fontColor(Color.White)
    Text(<span class="hljs-string">'6'</span>).fontSize(<span class="hljs-number">40</span>).backgroundColor(<span class="hljs-keyword">this</span>.worker6Color).fontColor(Color.White)
    Text(<span class="hljs-string">'7'</span>).fontSize(<span class="hljs-number">40</span>).backgroundColor(<span class="hljs-keyword">this</span>.worker7Color).fontColor(Color.White)
    Text(<span class="hljs-string">'8'</span>).fontSize(<span class="hljs-number">40</span>).backgroundColor(<span class="hljs-keyword">this</span>.worker8Color).fontColor(Color.White)
  }
  .width(<span class="hljs-string">'100%'</span>)
  .margin({top: <span class="hljs-number">20</span>})
  .justifyContent(FlexAlign.SpaceEvenly)

  Text(<span class="hljs-string">'Worker-postMessage'</span>)
    .fontSize(<span class="hljs-number">20</span>)
    .fontColor(Color.White)
    .borderRadius(<span class="hljs-string">'12vp'</span>)
    .backgroundColor(Color.Blue)
    .padding(<span class="hljs-number">10</span>)
    .stateStyles({
      focused: {
        .backgroundColor(Color.Green)
      },
      pressed: {
        .backgroundColor(Color.Green)
      },
      normal: {
        .backgroundColor(Color.Blue)
      }
    })
    .onClick(()=&gt;{
       <span class="hljs-keyword">this</span>.worker1Color = Color.Black
       <span class="hljs-keyword">this</span>.worker2Color = Color.Black
       <span class="hljs-keyword">this</span>.worker3Color = Color.Black
       <span class="hljs-keyword">this</span>.worker4Color = Color.Black
       <span class="hljs-keyword">this</span>.worker5Color = Color.Black
       <span class="hljs-keyword">this</span>.worker6Color = Color.Black
       <span class="hljs-keyword">this</span>.worker7Color = Color.Black
       <span class="hljs-keyword">this</span>.worker8Color = Color.Black

      <span class="hljs-keyword">let</span> tid = process.tid;

      console.log(<span class="hljs-string">'当前进程ID ：'</span> + tid)

      <span class="hljs-comment">// 发送消息到worker线程</span>
      wk1.postMessage({<span class="hljs-string">'no'</span>:<span class="hljs-number">1</span>,<span class="hljs-string">'threadID'</span>: tid,  <span class="hljs-string">'costtime'</span>: <span class="hljs-number">1000</span>})
      wk2.postMessage({<span class="hljs-string">'no'</span>:<span class="hljs-number">2</span>,<span class="hljs-string">'threadID'</span>: tid, <span class="hljs-string">'costtime'</span>: <span class="hljs-number">1500</span>})
      wk3.postMessage({<span class="hljs-string">'no'</span>:<span class="hljs-number">3</span>,<span class="hljs-string">'threadID'</span>: tid, <span class="hljs-string">'costtime'</span>: <span class="hljs-number">2000</span>})
      wk4.postMessage({<span class="hljs-string">'no'</span>:<span class="hljs-number">4</span>,<span class="hljs-string">'threadID'</span>: tid, <span class="hljs-string">'costtime'</span>: <span class="hljs-number">2500</span>})
      wk5.postMessage({<span class="hljs-string">'no'</span>:<span class="hljs-number">5</span>,<span class="hljs-string">'threadID'</span>: tid, <span class="hljs-string">'costtime'</span>: <span class="hljs-number">3000</span>})
      wk6.postMessage({<span class="hljs-string">'no'</span>:<span class="hljs-number">6</span>,<span class="hljs-string">'threadID'</span>: tid, <span class="hljs-string">'costtime'</span>: <span class="hljs-number">3500</span>})
      wk7.postMessage({<span class="hljs-string">'no'</span>:<span class="hljs-number">7</span>,<span class="hljs-string">'threadID'</span>: tid, <span class="hljs-string">'costtime'</span>: <span class="hljs-number">4000</span>})
      wk8.postMessage({<span class="hljs-string">'no'</span>:<span class="hljs-number">8</span>,<span class="hljs-string">'threadID'</span>: tid, <span class="hljs-string">'costtime'</span>: <span class="hljs-number">4500</span>})

    })
    .margin({top: <span class="hljs-number">20</span>})

  Text(<span class="hljs-keyword">this</span>.workerData).fontSize(<span class="hljs-number">25</span>).textAlign(TextAlign.Center)

  Text(<span class="hljs-string">'Worker-dispatchEvent-自定义类型'</span>)
    .fontSize(<span class="hljs-number">20</span>)
    .fontColor(Color.White)
    .borderRadius(<span class="hljs-string">'12vp'</span>)
    .backgroundColor(Color.Blue)
    .padding(<span class="hljs-number">10</span>)
    .stateStyles({
      focused: {
        .backgroundColor(Color.Green)
      },
      pressed: {
        .backgroundColor(Color.Green)
      },
      normal: {
        .backgroundColor(Color.Blue)
      }
    })
    .onClick(()=&gt;{

      <span class="hljs-keyword">let</span> tid = process.tid;

      console.log(<span class="hljs-string">'当前进程ID ：'</span> + tid)

      wk1.dispatchEvent({type: <span class="hljs-string">'WorkerTest'</span>, timeStamp: <span class="hljs-number">0</span>})

    })
    .margin({top: <span class="hljs-number">20</span>})

  Text(<span class="hljs-string">'Worker-dispatchEvent-message类型'</span>)
    .fontSize(<span class="hljs-number">20</span>)
    .fontColor(Color.White)
    .borderRadius(<span class="hljs-string">'12vp'</span>)
    .backgroundColor(Color.Blue)
    .padding(<span class="hljs-number">10</span>)
    .stateStyles({
      focused: {
        .backgroundColor(Color.Green)
      },
      pressed: {
        .backgroundColor(Color.Green)
      },
      normal: {
        .backgroundColor(Color.Blue)
      }
    })
    .onClick(()=&gt;{

      <span class="hljs-keyword">let</span> tid = process.tid;

      console.log(<span class="hljs-string">'当前进程ID ：'</span> + tid)

      wk1.dispatchEvent({type: <span class="hljs-string">'message'</span>, timeStamp: <span class="hljs-number">0</span>})

    })
    .margin({top: <span class="hljs-number">20</span>})

}.width(<span class="hljs-string">'100%'</span>).height(<span class="hljs-string">'100%'</span>)
.justifyContent(FlexAlign.Center)
}


}
<button style="position: absolute; padding: 4px 8px 0px; cursor: pointer; top: 8px; right: 8px; font-size: 14px;">复制</button>

通过IDEWorker模板创模板下文件（参见：指导）

Worker.ts, Worker2.ts, Worker3.ts, Worker4.ts, Worker5.ts, Worker6.ts, Worker7.ts, Worker8.ts

这些文件内容完全一样，仅仅是名称不一样

import worker, { ThreadWorkerGlobalScope, MessageEvents, ErrorEvent } from ‘@ohos.worker’;
import Logger from ‘…/common/Logger’;
import process from ‘@ohos.process’;
import emitter from ‘@ohos.events.emitter’


var workerPort : ThreadWorkerGlobalScope = worker.workerPort;


/**


    

  • 

    Defines the event handler to be called when the worker thread receives a message sent by the host thread.
    

    • 

  • 

    The event handler is executed in the worker thread.
    

    • 

  • 

  • 

    @param e message data
*/
workerPort.onmessage = function(e : MessageEvents) {
let tid = process.tid;
    

    Logger.d(tid + ’ worker收到了消息 ： ’ + JSON.stringify(e))
    

    setTimeout(()=>{
workerPort.postMessage(
{
‘no’: (e.data.no),
‘threadID’ : tid + ‘-’ + e.data.threadID,
‘label’: “worker”,
}
)
}, e.data.costtime)
    

    let eventData = {
data: {
‘threadID’ : tid + ‘-’ + e.data.threadID,
‘from’: ‘emitter’,
“content”: “c”,
“id”: 1,
}};
let innerEvent = {
eventId: 1847,
priority: emitter.EventPriority.HIGH
};
emitter.emit(innerEvent, eventData);
    

    • 



}


/**


    

  • Defines the event handler to be called when the worker receives a message that cannot be deserialized.
    • 

  • The event handler is executed in the worker thread.
    • 

  • 

  • @param e message data
*/
workerPort.onmessageerror = function(e : MessageEvents) {
Logger.d(JSON.stringify(e))
}
    • 



/**


    

  • Defines the event handler to be called when an exception occurs during worker execution.
    • 

  • The event handler is executed in the worker thread.
    • 

  • 

  • @param e error message
*/
workerPort.onerror = function(e : ErrorEvent) {
Logger.d(JSON.stringify(e))
}
<button style="position: absolute; padding: 4px 8px 0px; cursor: pointer; top: 8px; right: 8px; font-size: 14px;">复制</button>

在Build-profile.json5需要添加如上TS

“buildOption”: {
“sourceOption”: {
“workers”: [
‘./src/main/ets/workers/worker.ts’,
‘./src/main/ets/workers/worker2.ts’,
‘./src/main/ets/workers/worker3.ts’,
‘./src/main/ets/workers/worker4.ts’,
‘./src/main/ets/workers/worker5.ts’,
‘./src/main/ets/workers/worker6.ts’,
‘./src/main/ets/workers/worker7.ts’,
‘./src/main/ets/workers/worker8.ts’,
‘./src/main/ets/workers/worker9.ts’,
]
}
}
<button style="position: absolute; padding: 4px 8px 0px; cursor: pointer; top: 8px; right: 8px; font-size: 14px;">复制</button>
8 回复 
UI线程里先定义
var workerInstance = new worker.ThreadWorker("entry/ets/data/Worker.ts");//每个app最多8个Worker

我在Worker.ts这个文件，线程里

workerPort.onmessage = function (e: MessageEvents) {

globalThis.data=new MyData()

}

new一个globalThis.的对象，比如说GlobalThis.data=new MyData()

然后发送消息

workerPort.postMessage({ type: 'message', value: 'mydata_start' });

然后UI线程接收消息

workerInstance.onmessage = function(e) {
  // data：Worker线程发送的信息
  let data = e.data;
  if(data.value=='mydata_start') {
    if (globalThis.data != undefined）｛
//do something
    ｝
｝

发现这里的globalThis.data还是undefine

globalThis不能跨线程么？

更多关于HarmonyOS 鸿蒙Next中实现消息传递的实战系列教程也可以访问 https://www.itying.com/category-93-b0.html


上述代码中，订阅、发送消息最终实现的效果，类似Android中Livedata的observeForever功能，即页面/组件在后台或被覆盖时，也会接收消息并处理相关逻辑。

我的问题是，在上述功能的基础上，如果想实现：

1、页面/组件在回到前台时，才接收消息并处理相关逻辑；

2、如果有多个订阅者，可以设置多个订阅者都接收信息，或者任意一个订阅者接收消息后，其他订阅者不能接收该消息；

3、数据版本控制。即发送端每个数据自带版本号，当发送端发送的数据，订阅者来不及处理时，下次订阅者仅处理最新版本数据。

以上功能，在Android端，我们使用Livedata实现，但在HarmonyOS上，请问该如何做？谢谢。

建议

  1. 用 TypeScript 实现一个订阅者模式工具（如：https://github.com/brendangoldberg/ts-livedata）
  2. 十分了解UIAbility和Page的生命周期
  3. 实现自己的生命周期管理工具，或者等待下个HarmonyOS版本

感谢你的回复，我现在主要卡在生命周期这一步。 如果能在任意地方，简单便捷的获取ability及page的生命周期，后继的逻辑就方便很多，但现在没有办法实现。 我本来想试试能否hookability及page得到生命周期，但找了一圈资料，也没有找到相关解决方案。 所以目前来看，似乎只有等下个Harmony OS版本更新了。

祝你好运

wk1.addEventListener("WorkerTest", (e)=>{ this.workerData = JSON.stringify(e) })

这里设置了自动以监听，但是哪里调用了这个监听呢，wk1.dispatchEvent({type: 'WorkerTest', timeStamp: 0})这个dispatchEvent又是什么作用呢，不太理解。

我在主线程设置了监听，那么是在子线程是不是得有个地方调用"WorkerTest"它，就是回调的实现？

有个需求 要在主线程里面传入好多个监听,子线程里面设置一个while循环，然后依次给调起主线程中的监听器，主线程中的每个监听执行结束后再告诉子线程，然后子线程继续执行下调用下一个监听

HarmonyOS（鸿蒙）消息传递Next主要涉及系统内的通信机制优化与升级，旨在为用户提供更高效、安全的信息交互体验。在鸿蒙系统中，消息传递框架得到了全面重构，引入了更加灵活和强大的消息处理能力。

鸿蒙消息传递Next可能包括以下几个方面的改进：

  1. 高效传输：通过优化底层通信协议和传输算法，实现消息的快速、准确传递，降低延迟，提高系统响应速度。

  2. 安全增强：加强消息传输过程中的加密和验证机制，确保信息的安全性和隐私保护，防止数据泄露和篡改。

  3. 多设备协同：支持跨设备、跨平台的消息同步和共享，实现手机、平板、电视等智能设备之间的无缝连接和协同工作。

  4. 智能分发：根据用户的使用习惯和上下文环境，智能地分发和展示消息，提升用户体验。

  5. 扩展性：提供丰富的API和开发者工具，支持开发者快速接入和定制消息传递功能，满足不同应用场景的需求。

如果你在使用鸿蒙消息传递功能时遇到问题，可以尝试检查系统更新、重启设备或清理缓存等方法进行初步排查。如果问题依旧没法解决请联系官网客服，官网地址是：https://www.itying.com/category-93-b0.html。

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