iview modal 点击打开窗口，打开前先销毁里面的内容再打开

<Modal v-model="addSubOrgModal"
           @on-cancel="addSubOrgCancel"
           @on-visible-change="orgOnVisibleChange"
           width="600"
           :mask-closable="false"
           title="新增下级机构">
      <org-form ref="orgFormAdd"
                v-if="addSubOrgModalVif"
                org-add-id="orgAddId"></org-form>
      <div slot="footer">
        <Button @click="addSubOrgCancel">关闭</Button>
        <Button type="primary"
                @click="addSubOrgOk">保存</Button>

      </div>
    </Modal>

addSubOrg () {
      // this.$Message.success('新增下级机构事件')
      let seleArr = this.$refs.tables.$refs.tablesMain.getSelection()
      if (seleArr.length !== 1) {
        this.$Message.warning('请选择一条数据操作！')
      } else {
        this.addSubOrgModal = true
        this.addSubOrgModalVif = false
        this.$nextTick(() => {
          this.addSubOrgModalVif = true
          this.$nextTick(() => {
            this.$refs.orgFormAdd.orgFormAddInit(seleArr[0])
          })
        })
      }
    },