according to the on-demand introduction mode provided by the official website 
 the import and Vue.use (iView) in the entrance should be removed from 
 babelrc 
  "plugins": ["transform-vue-jsx", "transform-runtime",[
    "import", {
      "libraryName": "iview",
      "libraryDirectory": "src/components"
    }]]component
<template>
    <div class="task-bar-wrapper">
        <Button>Default</Button>
    </div>
</template>
<script>
    import {Button} from "iview";
    export default {
        components: {
            Button
        },
        data() {
            return {
            }
        }
    }
</script>error
  
 
