效果如下:

实现代码如下，下面具体我都写了注释

import { router, window } from '@kit.ArkUI';
import { BusinessError } from '@kit.BasicServicesKit';
import { LogUtil } from '../../utils/logutil';

@Component
@Entry
struct Splash {
  timeId?: number; // 定时器
  @State num: number = 5; // 倒计时

  build() {
    Stack() {
      // 背景图片
      Image($r('app.media.splash_bg'))
        .size({ width: '100%', height: '100%' })
        .zIndex(-1); // 确保背景图片在最底层
      Column() {
        // 最右边显示
        Button('立即体验' + this.num)
          .width('30%')
          .height('6%')
          .fontSize('16fp')
          .margin({ top: '10%', right: '3%' })
          .alignSelf(ItemAlign.End) // 对齐到右侧
          .onClick(() => {
            LogUtil.info('点击立即体验');
            this.clearTimerAndNavigate();
          });

      }.size({ width: '100%', height: '100%' });
    }.size({ width: '100%', height: '100%' });
  }

  /**
   * 页面显示时，开始倒计时
   */
  onPageShow() {
    this.setImmersive();
    this.countDown();
    LogUtil.info('开始倒计时了');
  }

  /**
   * 沉浸式状态栏
   */
  private setImmersive() {
    window.getLastWindow(getContext()).then(win => {
      win.setWindowLayoutFullScreen(true);
      let area = win.getWindowAvoidArea(window.AvoidAreaType.TYPE_SYSTEM);
      let height = area.topRect.height;
      let vpheight = px2vp(height);
      AppStorage.setOrCreate('topHeight', vpheight);
      win.setWindowSystemBarProperties({ statusBarContentColor: '#ffffff' }); // 设置状态栏字体颜色
    });
  }

  /**
   * 把倒计时封装方法
   */
  private countDown() {
    let timeId = setInterval(() => {
      this.num--;
      if (this.num === 0) {
        clearInterval(this.timeId);
        LogUtil.info('倒计时结束');
        this.navigateToNextPage(); // 跳转到下一页
      }
    }, 1000);
    this.timeId = timeId;
  }

  /**
   * 清除定时器并跳转下一页
   */
  private clearTimerAndNavigate() {
    clearInterval(this.timeId);
    this.navigateToNextPage();
  }

  /**
   * 跳转下一页
   */
  private navigateToNextPage() {
    router.pushUrl({ url: 'pages/login/Login' }).then(() => {
      console.info('成功跳转到第二页。');
    }).catch((err: BusinessError) => {
      console.error(`无法跳转到第二页。错误码为${err.code}, 错误消息 ${err.message}`);
    });
  }

  /**
   * 页面销毁时，清除定时器
   */
  onDestroy() {
    this.num = 5;
    clearInterval(this.timeId);
    LogUtil.info('清除定时器');
  }
}