无法读取网页上的属性'addEventListener'为null

Question

我尝试通过鼠标事件使图像幻灯片可变形，但在网页上出现此错误。我该如何解决这个问题

下面的我的javascript代码；

var slider = document.querySelector('card-slider-wrapper');
let isDown = false;
let startX;
let scrollLeft;

slider.addEventListener('mousedown', (e) => {
  isDown = true;
  slider.classList.add('active');
  startX = e.pageX - slider.offsetLeft;
  scrollLeft = slider.scrollLeft;
  console.log(startX);
});
slider.addEventListener('mouseleave', () => {
  isDown = false;
  slider.classList.remove('active');
});
slider.addEventListener('mouseup', () => {
  isDown = false;
  slider.classList.add('active');
});
slider.addEventListener('mousemove', (e) => {
  if (!isDown) return;
  e.preventDefault();
  const x = e.pageX - slider.offsetLeft;
  const walk = (x - startX) * 3;
  slider.scrollLeft = scrollLeft - walk;
});

Answer 1

缺少类别或ID标识符

应该是

document.querySelector('.card-slider-wrapper')

或

document.querySelector('#card-slider-wrapper')