js教程实例讲解js如何实现dom元素横向及纵向滚动的动画

let timer:any = null // 定时器
let TargetLocation = -1 // 上一次点击应该滚动到的目标位置
let toltalSpace = 0 // 本次要滚动的距离

/**
 * @info 竖直滚动
 * @info 滚动动画 hz 刷新率 可以修改滚动的速度
 * @params dom：要滚动的元素； space 要滚动的距离； istop 滚动的方向;
*/
const movingColumn = (dom:HTMLDivElement, space: number, istop:boolean) => {

  // 用户快速点击 则把上次未滚动的距离与本次滚动结合再一起
  if (timer && TargetLocation !== -1) {
    toltalSpace += TargetLocation - dom.scrollTop
    // 计算本次的目标距离
    if(istop) {
      TargetLocation = dom.scrollTop + toltalSpace + space
    } else {
      TargetLocation = dom.scrollTop + toltalSpace - space
    }
  } else if (!timer) {
    toltalSpace = 0
    TargetLocation = -1
  }

  if (istop) {
    toltalSpace -= space
  } else {
    toltalSpace += space
  }

  // 获取本次的目标位置
  const position = dom.scrollTop
  TargetLocation = position + toltalSpace

  clearInterval(timer)
  timer = null
  const hz = 60
  let i = 1
  timer = setInterval(() => {
    dom.scrollTop = position + i * toltalSpace / hz
    ++i
    if (i >= hz) {
      clearInterval(timer)
      timer = null
      dom.scrollTop = TargetLocation // 位置修正
      toltalSpace = 0
      TargetLocation = -1
    }
  }, 1)
}


/**
 * @info 水平滚动
 * @info 滚动动画 hz 刷新率 可以修改滚动的速度
 * @params dom：要滚动的元素； space 要滚动的距离； isLeft 滚动的方向;
*/
const moving = (dom:HTMLDivElement, space: number, isLeft:boolean) => {

  // 用户快速点击 则把上次未滚动的距离与本次滚动结合再一起
  if (timer && TargetLocation !== -1) {
    toltalSpace += TargetLocation - dom.scrollLeft
    // 计算本次的目标距离
    if(isLeft) {
      TargetLocation = dom.scrollLeft + toltalSpace + space
    } else {
      TargetLocation = dom.scrollLeft + toltalSpace - space
    }
  } else if (!timer) {
    toltalSpace = 0
    TargetLocation = -1
  }

  if (isLeft) {
    toltalSpace -= space
  } else {
    toltalSpace += space
  }

  // 获取本次的目标位置
  const position = dom.scrollLeft
  TargetLocation = position + toltalSpace

  clearInterval(timer)
  timer = null
  const hz = 60
  let i = 1
  timer = setInterval(() => {
    dom.scrollLeft = position + i * toltalSpace / hz
    ++i
    if (i >= hz) {
      clearInterval(timer)
      timer = null
      dom.scrollLeft = TargetLocation // 位置修正
      toltalSpace = 0
      TargetLocation = -1
    }
  }, 1)
}

export {
  moving,
  movingColumn
}