1、是否滚动到底部
isScrollBottom() {
// 是否滚动到了底部
this.box = this.$refs.chatListWrapper
var clientHeight = this.box.clientHeight
var scrollTop = this.box.scrollTop
var scrollHeight = this.box.scrollHeight
if (scrollTop + clientHeight == scrollHeight) {
this.$store.dispatch('setBottomBtn', false, { root: true }) // 隐藏直达最新消息按钮
this.isBottom = true
this.isTop = false
} else {
this.$store.dispatch('setBottomBtn', true, { root: true }) // 显示直达最新消息按钮
this.isTop = false
this.isBottom = false
if (scrollTop == 0) {
this.isTop = true
}
}
},
2、scroll滚动方向判断
getDirection() {
// scroll滚动方向~~~~
this.box = this.$refs.chatListWrapper
var scrollTop = this.box.scrollTop
var scroll = scrollTop - this.initTop
this.initTop = scrollTop
let dir = 'down'
if (scroll < 0) {
dir = 'up'
} else {
dir = 'down'
}
return dir
},
3、滚动节流
1）、在滚动的dom上绑定scroll事件，监听滚动
2）、data中定义：fnScroll: () => {}, 初始值
3）、mounted中给fnScroll函数赋值，_.throttle实现滚动节流
this.fnScroll = _.throttle(() => {
}, 500)
4、获取滚动可视区域内dom：
实现注意：判断当前元素是否在可视区域内，若在则存到isSeeDomArr中，然后循环isSeeDomArr数组，拿到当前可视区域内的最后一个dom,再去判断是否更新对应的咨询轨迹。
不要滚动时就去更新，这样会造成不停请求更新，最后一次请求可能无效，造成数据的错乱
sendRead() {
const chatLi = document
.getElementById('chat_list_wrapper')
.getElementsByTagName('li')
var container = this.$refs.chatListWrapper
var swHeight = container.clientHeight
const scrollTop = container.scrollTop
const aa = swHeight + scrollTop
let isSeeDomArr = []
for (let j = 0; j < chatLi.length; j++) {
if (scrollTop < chatLi[j].offsetTop && chatLi[j].offsetTop < aa) {
isSeeDomArr.push(chatLi[j]) //将可视区域内所有dom存储到isSeeDomArr
}
}
if (isSeeDomArr.length) {
// 非 ceo接诊台更新消息的已读状态
if (this.$route.path.indexOf('diagnose/ceo') === -1) {
for (let m = 0; m < isSeeDomArr.length; m++) {
const isSelfSend = isSeeDomArr[m].getAttribute('isSelfSend')
const msgStatus = isSeeDomArr[m].getAttribute('msgStatus')
const msgType = isSeeDomArr[m].getAttribute('msgType')
if (!isSelfSend && !msgStatus && msgType !== 'notice') {
const _id = isSeeDomArr[m].getAttribute('id')
this.sendReadApi(_id)
}
}
}
// 更新聊天对应的咨询轨迹
this.setCurrentFdAsk(
isSeeDomArr[isSeeDomArr.length - 1].getAttribute('fdAsk')
)
}
},
the end：滚动加载这些判断前前后后改了好多次，这次终于感觉逻辑比较清晰了，也算对自己有个交代。。。