$ npm install -g vue-cli
$ vue init webpack-simple ./file-upload # Follow the prompts.
$ cd ./file-upload
$ npm install # or yarn

// FileSelect.vue

<template>
 <label class="file-select">
 <div class="select-button">
  <span v-if="value">Selected File: {{value.name}}</span>
  <span v-else>Select File</span>
 </div>
 <input type="file" @change="handleFileChange"/>
 </label>
</template>

// FileSelect.vue
...
<style scoped>
.file-select > .select-button {
 padding: 1rem;

 color: white;
 background-color: #2EA169;

 border-radius: .3rem;

 text-align: center;
 font-weight: bold;
}

/* Don't forget to hide the original file input! */
.file-select > input[type="file"] {
 display: none;
}
</style>

<input v-model="sth" />
// 上面等价于下面
<input v-bind:value="sth" v-on:input="sth = $event.target.value" />

// FileSelect.vue 
<script>
export default {
 props: {
 // 这里接受一个 value 因为 v-model 会给组件传递一个 value 属性
 value: File
 },

 methods: {
 handleFileChange(e) {
  // 同样触发一个 input 来配合 v-model 的使用
  this.$emit('input', e.target.files[0])
 }
 }
}
</script>

// App.vue
<template>
 <div>
 <p>选择文件: <file-select v-model="file"></file-select></p>
 <p v-if="file">{{file.name}}</p>
 </div>
</template>

<script>
import FileSelect from './FileSelect.vue'

export default {
 components: {
 FileSelect
 },

 data() {
 return {
  file: null
 }
 }
}
</script>