HarmonyOS Worker线程中，如何保存成员对象？

当用Worker创建了一个线程之后，我想在worker里始终持有一个对象，如下：

const workerPort: ThreadWorkerGlobalScope = worker.workerPort;  
  
const testBean: TestBean = new TestBean()  
  
workerPort.onmessage = (e: MessageEvents) => {  
  testBean.count ++;  
})1.
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其中TestBean结构如下：

class TestBean {  
    count: number = 0  
}1.
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结果我发了10个消息，结果发现testBean里的count每次都是0，说明Worker中没有持有这个对象。

想问问老师怎么实现这个需求呢？

HarmonyOS

put_get

2024-10-21 12:32:40

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回答 1

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按时间

Heiang

可以考虑使用ShareArrayBuffer，关键代码：主线程中：

const workerInstance = new worker.ThreadWorker("entry/ets/pages/worker1.ets");  
const sab = new SharedArrayBuffer(1024);//创建一个sharedArrayBuffer  
workerInstance.postMessage(sab);//向worker发送消息  
worker中：  
import worker, { MessageEvents, ErrorEvent } from '@ohos.worker';  
// 创建worker线程中与主线程通信的对象  
const workerPort = worker.workerPort  
let  sharedArray:Int32Array|null =null;//定义SharedArrayBuffer的视图，方便读写  
// worker线程接收主线程信息  
workerPort.onmessage = (e: MessageEvents): void => {  
  // data：主线程发送的信息  
  let data: SharedArrayBuffer = e.data;  
  if(!sharedArray){  
    sharedArray = new Int32Array(data)//在主线程接受的共享内存上建立视图  
  }  
  sharedArray[0]++;//数据操作  
  console.log(" test show worker监听到消息worker.ets onmessage",sharedArray[0]);  
}  
// worker线程发生error的回调  
workerPort.onerror = (err: ErrorEvent) => {  
  console.log("worker.ets onerror" + err.message);  
}1.
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sharedArrayBuffer可共享对象可以存储任何类型的数据，文档：

https://developer.huawei.com/consumer/cn/doc/harmonyos-guides-V5/serialization-support-types-V5#可共享对象

代码：

主线程：

import { ErrorEvent, MessageEvents, worker } from '@kit.ArkTS';  
const workerInstance = new worker.ThreadWorker("entry/ets/pages/worker1.ets");  
const sab = new SharedArrayBuffer(1024);  
let sharedArray = new Array<Object>(sab)//在主线程的共享内存上建立视图  
@Entry  
@Component  
struct Index {  
  @State message: string = 'Hello World';  
  build() {  
    Row() {  
      Column() {  
        Text(this.message)  
          .fontSize(50)  
          .fontWeight(FontWeight.Bold)  
        Button("向worker发送消息").onClick(()=>{  
          sharedArray[0]=new Object({value:'测试内容'})  
          workerInstance.postMessage(sharedArray);//直接向worker线程发送共享内存的视图  
        })  
      }  
      .width('100%')  
    }  
    .height('100%')  
  }  
}1.
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worker：

import worker, { MessageEvents, ErrorEvent } from '@ohos.worker';  
// 创建worker线程中与主线程通信的对象  
const workerPort = worker.workerPort  
let  sharedArray:Array<Object>|null =null;  
// worker线程接收主线程信息  
workerPort.onmessage = (e: MessageEvents): void => {  
  // data：主线程发送的信息  
  let data: SharedArrayBuffer = e.data;  
  if(!sharedArray){  
    sharedArray = new Array<Object>(data)  
  }  
  console.log("ctest show worker监听到消息worker.ets onmessage",JSON.stringify(sharedArray[0]));//stringify为了输出查看  
}  
  
// worker线程发生error的回调  
workerPort.onerror = (err: ErrorEvent) => {  
  console.log("worker.ets onerror" + err.message);  
}1.
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这个是上面demo的实现参考最后一部分Stage模型配置：

https://developer.huawei.com/consumer/cn/doc/harmonyos-references-V5/js-apis-worker-V5#stage模型

1.worker线程ets：（路径：ets/pages/workers/worker1.ets）

import worker, { MessageEvents, ErrorEvent } from '@ohos.worker';  
// 创建worker线程中与主线程通信的对象  
const workerPort = worker.workerPort  
let sharedArray:Array<Object>|null =null;  
// worker线程接收主线程信息  
workerPort.onmessage = (e: MessageEvents): void => {  
  // data：主线程发送的信息  
  let data: SharedArrayBuffer = e.data;  
  if(!sharedArray){  
    sharedArray = new Array<Object>(data)  
  }  
  console.log("ctest show worker监听到消息worker.ets onmessage",JSON.stringify(sharedArray[0]));  
}  
// worker线程发生error的回调  
workerPort.onerror = (err: ErrorEvent) => {  
  console.log("worker.ets onerror" + err.message);  
}1.
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2. 主线程页面ets：（路径：ets/pages/Index.ets）

import { ErrorEvent, MessageEvents, worker } from '@kit.ArkTS';  
import { socket } from '@kit.NetworkKit';  
const workerInstance = new worker.ThreadWorker("entry/ets/pages/workers/worker1.ets");  
const sab = new SharedArrayBuffer(1024);  
let sharedArray = new Array<Object>(sab)  
@Entry  
@Component  
struct Index {  
  @State message: string = 'Hello World';  
  build() {  
    Row() {  
      Column() {  
        Text(this.message)  
          .fontSize(50)  
          .fontWeight(FontWeight.Bold)  
        Button("向worker发送消息").onClick(()=>{  
          let t:socket.TLSSocket = socket.constructTLSSocketInstance();  
          sharedArray[0] = t;  
          workerInstance.postMessage(sharedArray);  
        })  
      }  
      .width('100%')  
    }  
    .height('100%')  
  }  
}1.
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3. build-profile.json5（路径：ets/build-profile.json5）buildOption下添加：

"buildOption": {  
  "sourceOption": {  
    "workers": [  
    "./src/main/ets/pages/workers/worker1.ets"  
    ]  
  }  
}1.
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2024-10-21 17:28:08

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