HarmonyOS ArkTS有类似main方法，可以单独运行1个方法吗

可以在拥有entry入口的ets文件的相关组件的点击事件或者自定义组件的生命周期中如aboutToAppear(): void {

}中执行对应的方法。

参考案例：

import { BusinessError } from '@kit.BasicServicesKit';
import { userAuth } from '@kit.UserAuthenticationKit';

@Entry
@Component
struct UserAuthTest {
  build() {
    Column(){
      Button('认证测试')
        .onClick(() =>{
          console.info("开始测试")
          test()
        })
    }
    .width('100%')
    .height('100%')
    .justifyContent(FlexAlign.Center)
  }
}

function test(): void{
  // 设置认证参数
  const authParam: userAuth.AuthParam = {
    challenge: new Uint8Array([49, 49, 49, 49, 49, 49]),
    authType: [userAuth.UserAuthType.PIN, userAuth.UserAuthType.FACE],
    authTrustLevel: userAuth.AuthTrustLevel.ATL3,
  };
  // 配置认证界面
  const widgetParam: userAuth.WidgetParam = {
    title: '请进行身份认证',
  };
  try {
    // 获取认证对象
    let userAuthInstance = userAuth.getUserAuthInstance(authParam, widgetParam);
    console.info('get userAuth instance success');
    // 订阅认证结果
    userAuthInstance.on('result', {
      onResult(result) {
        console.info(`userAuthInstance callback result: ${JSON.stringify(result)}`);
        // 可在认证结束或其他业务需要场景，取消订阅认证结果
        userAuthInstance.off('result');
      }
    });
    console.info('auth on success');
    userAuthInstance.start();
    console.info('auth start success');
  } catch (error) {
    const err: BusinessError = error as BusinessError;
    console.error(`auth catch error. Code is ${err?.code}, message is ${err?.message}`);
  }
}