getOptionsA() {

      this.$axios

        .get('http://localhost:55629/api/GetClassifies?pid=0')

        .then((res) => {

          this.optionsA = res.data

        })

    },

    getOptionsB(value) {

        //给第一级ID 赋值

       this.resetForm.CIdA = value[0]

      this.$axios

        .get(`http://localhost:55629/api/GetClassifies?pid=${value[0]}`)

        .then((res) => {

          this.optionsB = res.data

        })

    },

 <el-cascader-panel :options="optionsA"

                           :props="{ value: 'CId', label: 'CName' }"

                           ref="optA"

                           @change="getOptionsB"></el-cascader-panel>

 if (this.active++ > 2) this.active = 0 //更新步骤条

    //反填图片

    this.imageUrl = this.ruleForm.ImgPath

    //反填发类

    this.ruleForm.BId = this.$route.query.BName

    //反填商品分类

    this.optAName = this.$route.query.CNameA

    this.optBName = this.$route.query.CNameB