Worker同步调用宿主线程的接口

如果一个接口已在宿主线程中实现，Worker可以通过以下方式调用该接口。

以下示例展示了Worker如何同步调用宿主线程的接口。

首先，在宿主线程实现需要调用的接口，并创建Worker对象，在Worker对象上注册需要调用的对象。

// IconItemSource.ets
export class IconItemSource {
  image: string|Resource = '';
  text: string|Resource = '';

  constructor(image: string|Resource = '', text: string|Resource = '') {
    this.image = image;
    this.text = text;
  }
}

// WorkerCallGlobalUsage.ets
import worker from '@ohos.worker';
import { IconItemSource } from './IconItemSource';

// 创建Worker对象
const workerInstance: worker.ThreadWorker = new worker.ThreadWorker("entry/ets/pages/workers/Worker.ts");

class PicData {
  public iconItemSourceList: IconItemSource[] = [];

  public setUp(): string {
    for (let index = 0; index < 20; index++) {
      const numStart: number = index * 6;
      // 此处循环使用6张图片资源
      this.iconItemSourceList.push(new IconItemSource('$media:startIcon', `item${numStart + 1}`));
      this.iconItemSourceList.push(new IconItemSource('$media:background', `item${numStart + 2}`));
      this.iconItemSourceList.push(new IconItemSource('$media:foreground', `item${numStart + 3}`));
      this.iconItemSourceList.push(new IconItemSource('$media:startIcon', `item${numStart + 4}`));
      this.iconItemSourceList.push(new IconItemSource('$media:background', `item${numStart + 5}`));
      this.iconItemSourceList.push(new IconItemSource('$media:foreground', `item${numStart + 6}`));

    }
    return "setUpIconItemSourceList success!";
  }
}

let picData = new PicData();
// 在Worker上注册需要调用的对象
workerInstance.registerGlobalCallObject("picData", picData);
workerInstance.postMessage("run setUp in picData");

然后，在Worker中通过callGlobalCallObjectMethod接口可以调用宿主线程中的setUp()方法。

// Worker.ets
import { ErrorEvent, MessageEvents, ThreadWorkerGlobalScope, worker } from '@kit.ArkTS';
const workerPort: ThreadWorkerGlobalScope = worker.workerPort;
try {
  // 调用方法无入参
  let res: string = workerPort.callGlobalCallObjectMethod("picData", "setUp", 0) as string;
  console.error("worker: ", res);
} catch (error) {
  // 异常处理
  console.error("worker: error code is " + error.code + " error message is " + error.message);
}