vue-markdown 之 markdown-it, 以及 table of content 的实现：markdown-it-toc-and-anchor

1. npm install --save uslug markdown-it markdown-it-toc-and-anchor

2. 主要代码

• <template>
    <div id="lab_exp_book">
  
          ... ...
  
            <div class="directory_box">
              <div class="directory_title">目录</div>
              <ul class="directory_ul">
                <li v-for="(item, index) in tocShow" :key="index">
                  <div v-if="item.children.length===0">
                    <a :class="{active: curContentScrollTop===item.anchorY}" class="lab_section_class hover_change_color"
                       @click="handleDirClick(item)" href="javascript:">{{item.nodeName}}</a>
                  </div>
  
                  <div v-else>
                    <div :class="{active: curContentScrollTop===item.anchorY || (!item.anchorY && index === 0)}" class="lab_section_title hover_change_color"
                         @click="handleDirClick(item)">{{item.nodeName}}</div>
                    <ul class="lab_section_children">
                      <li v-for="(each, index) in item.children" :key="index">
                        <div v-if="each.children.length===0">
                          <a  :class="{active: curContentScrollTop===each.anchorY}" class="lab_section_class hover_change_color"
                              @click="handleDirClick(each)" href="javascript:">{{each.nodeName}}</a>
                        </div>
  
                        <div v-else>
                          <div :class="{active: curContentScrollTop===each.anchorY}" class="lab_section_title hover_change_color"
                               @click="handleDirClick(each)">{{each.nodeName}}</div>
                          <ul class="lab_section_children">
                            <li v-for="(third, index) in each.children" :key="index">
                              <div>
                                <a  :class="{active: curContentScrollTop===third.anchorY}" class="lab_section_class hover_change_color"
                                    @click="handleDirClick(third)" href="javascript:">{{third.nodeName}}</a>
                              </div>
                            </li>
                          </ul>
                        </div>
                      </li>
                    </ul>
                  </div>
                </li>
              </ul>
  
              <div class="directory_tips">开始学习后可阅读实验手册内容</div>
            </div>
          </div>
  
          <div class="right_book_content" ref="rightBookContent">
            <div class="book_box" v-if="1">
              <div class="lab_simple_content clearfix" v-html="htmlStr">
              </div>
            </div>
  
          ... ...
  
    </div>
  </template>
  
  <script>
    import uslug from 'uslug'
    import MarkdownIt from 'markdown-it'
    import markdownItTocAndAnchor from 'markdown-it-toc-and-anchor'
    data () {
        return {
           mdStr: '相关md字符串',
           htmlStr: '',    // 渲染到页面
           tocArray: [],
           tocShow: [],    // 渲染到页面
           isFirstClickDir: true,
           curContentScrollTop: 2
        }
    },
      computed: {
        ...mapState({
          labDirectory: state => state.lab.labDirectory
        })
      },
      watch: {
        tocArray: {
          deep: true,
          handler (newValue) {
            const oldArr = JSON.parse(JSON.stringify(newValue))
  
            let tocArr = []
            let cur1Arr = null
            let cur2Arr = null
            let cur3Arr = null
            let cur4Arr = null
            let cur5Arr = null
            oldArr.reduce((newArr, next) => {
              if (next.level === 2) {
                cur1Arr = JSON.parse(JSON.stringify(next))
                cur1Arr.children = []
                cur1Arr.nodeName = cur1Arr.content
                cur2Arr = cur1Arr.children
                tocArr.push(cur1Arr)
              } else if (next.level === 3) {
                cur3Arr = JSON.parse(JSON.stringify(next))
                cur3Arr.children = []
                cur3Arr.nodeName = cur3Arr.content
                cur4Arr = cur3Arr.children
                cur2Arr.push(cur3Arr)
              } else if (next.level === 4) {
                cur5Arr = JSON.parse(JSON.stringify(next))
                cur5Arr.children = []
                cur5Arr.nodeName = cur5Arr.content
                // cur6Arr = cur5Arr.children
                cur4Arr.push(cur5Arr)
              }
              return newArr
            }, [])
  
            this.tocShow = tocArr
          }
        }
      },
      async mounted () {
        this.myConsole('_labExpBookInit')
        this._initLabExpBook()
        await this.$store.dispatch('getLabDirectory')
      },
      methods: {
        _uslugify(x) {
          return uslug(x)
        },
        _initLabExpBook () {
          let md = new MarkdownIt({
            html: false,
            xhtmlOut: true,
            typographer: true
          })
  
          md.use(markdownItTocAndAnchor, {slugify: this._uslugify})
  
          this.htmlStr = md.set({
            tocCallback: (tocMarkdown, tocArray, tocHtml) => {
              this.tocArray = tocArray
            }
          }).render(this.mdStr)
        },
        handleDirClick(dirNode) {
          window.scrollTo(0, 502)
          if (this.isFirstClickDir) {
            this.isFirstClickDir = false
            this._initDirScrollPos()
            bindEventFunc(this.$refs.rightBookContent, 'scroll', () => {
              this.curContentScrollTop = this.$refs.rightBookContent.scrollTop
            })
          }
          this.$refs.rightBookContent.scrollTo({ top: dirNode.anchorY, left: 0, behavior: 'smooth' })
        },
        _initDirScrollPos () {
          this.tocShow = this.tocShow.map((ele) => {
            myConsole(ele.anchor)
            this._addAnchorY(ele)
            if (ele.children.length > 0) {
              ele.children.forEach((each, i) => {
                myConsole(ele.children[i].anchor)
                this._addAnchorY(ele.children[i])
                if (each.children.length > 0) {
                  each.children.forEach((one, j) => {
                    myConsole(ele.children[i].children[j].anchor)
                    this._addAnchorY(ele.children[i].children[j])
                  })
                }
              })
            }
            return ele
          })
        },
        _addAnchorY (ele) {
          ele.anchorY = document.getElementById(ele.anchor).getBoundingClientRect().top - 120
        }
      ... ...
  </script>

3. 效果截图

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