HarmonyOS webview统一清除缓存的方法

可以参考以下文档：https://developer.huawei.com/consumer/cn/doc/harmonyos-references-V5/js-apis-webview-V5#removecache

可以通过设置全局来处理解决不依赖具体web页面

export class GlobalContext {
  private constructor() {
  }

  private static instance: GlobalContext;
  private _objects = new Map<string, Object>();

  public static getContext(): GlobalContext {
    if (!GlobalContext.instance) {
      GlobalContext.instance = new GlobalContext();
    }
    return GlobalContext.instance;
  }

  getObject(value: string): Object | undefined {
    return this._objects.get(value);
  }

  setObject(key: string, objectClass: Object): void {
    this._objects.set(key, objectClass);
  }
}
//某一个web组件赋值给全局
Web({ src: 'https://www.huawei.com', controller: this.webcontroller })
  .onControllerAttached(() => {
    GlobalContext.getContext().setObject('webcontroller', this.webcontroller)
  })
  .height(200)
  .width('100%')

//清除缓存
Button('removeCache')
  .onClick(() => {
    try {
      let webcontroller = GlobalContext.getContext().getObject('webcontroller') as web_webview.WebviewController
      webcontroller.removeCache(true);
    } catch (error) {
      let e: BusinessError = error as BusinessError;
      console.error(`ErrorCode: ${e.code}, Message: ${e.message}`);
    }
  })