worker模块是arkts中多线程的一种使用方式
@ohos.worker (启动一个Worker)
Worker是与主线程并行的独立线程。创建Worker的线程称之为宿主线程，Worker自身的线程称之为Worker线程。创建Worker传入的url文件在Worker线程中执行，可以处理耗时操作但不可以直接操作UI。
Worker主要作用是为应用程序提供一个多线程的运行环境，可满足应用程序在执行过程中与主线程分离，在后台线程中运行一个脚本操作耗时操作，极大避免类似于计算密集型或高延迟的任务阻塞主线程的运行。由于Worker一旦被创建则不会主动被销毁，若不处于任务状态一直运行，在一定程度上会造成资源的浪费，应及时关闭空闲的Worker。
创建worker文件
import { ErrorEvent, MessageEvents, ThreadWorkerGlobalScope, worker } from '@kit.ArkTS';
const 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 = (e: MessageEvents) => {
console.log(`e type:${JSON.stringify(e.data)}`)
console.log('start worker...............')
}
/**
* 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 = (e: MessageEvents) => {
}
/**
* 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 = (e: ErrorEvent) => {
}
主线程创建worker
const workerInstance: worker.ThreadWorker = new worker.ThreadWorker('entry/ets/workers/Worker.ets');
let done = false;
// 接收Worker子线程的结果
workerInstance.onmessage = (() => {
console.info('MyWorker.ts onmessage');
if (!done) {
workerInstance.postMessage({ 'type': 1, 'value': 0 });
done = true;
}
})
workerInstance.onerror = (() => {
// 接收Worker子线程的错误信息
})
// 向Worker子线程发送训练消息
workerInstance.postMessage({ 'type': 0 });
