Vue3（框架setup）手挫滚动某距离固定导航

实列：

<div :class="['jx_box',isFixed&&'fixed-nav']"> //添加动态class

      <div class="jx_bx">精选</div>

 </div>

js部分：

const isFixed = ref(false);

  const handleScroll = () => {

    const scrollPosition = window.scrollY;

    isFixed.value = scrollPosition > 300;

    console.log(scrollPosition,isFixed.value);

  };

  onMounted(() => {

    window.addEventListener('scroll', handleScroll);

  });

  onUnmounted(() => {

    window.removeEventListener('scroll', handleScroll);

  });

样式部分省略