滚动监听函数节流闭包详解

function throttle(func, delay) {
  let previous = 0;
  let timeout = null;
return function(...args) {
const now = Date.now();
const remaining = delay - (now - previous);
if (remaining <= 0) {
  func.apply(this, args);
  previous = now;
} else if (!timeout) {
  timeout = setTimeout(() => {
    func.apply(this, args);
    previous = Date.now();
    timeout = null;
  }, remaining);
}
};
}

const handleScroll = throttle(() => {
  console.log('滚动位置：', window.pageYOffset);
  // 执行懒加载、吸顶、视差等逻辑
}, 100); // 每100ms最多执行一次
window.addEventListener('scroll', handleScroll);

function throttle(func, delay) {
  let previous = 0;
  let timeout = null;
const throttled = function(...args) {
const now = Date.now();
const remaining = delay - (now - previous);
if (remaining <= 0) {
  func.apply(this, args);
  previous = now;
} else if (!timeout) {
  timeout = setTimeout(() => {
    func.apply(this, args);
    previous = Date.now();
    timeout = null;
  }, remaining);
}
};
throttled.cancel = () => {
if (timeout) {
clearTimeout(timeout);
timeout = null;
}
};
return throttled;
}