Vue は、シンプルで軽量なアップロード ファイル コンポーネントの例をカプセル化します。

<template>
 <p class="content">
 <label for="my-upload">
  <span>上传</span>
 </label>
  <my-upload
   ref="myUpload"
   :file-list="fileList"
   action="/uploadPicture"
   :data="param"
   :on-change="onChange"
   :on-progress="uploadProgress"
   :on-success="uploadSuccess"
   :on-failed="uploadFailed"
   multiple
   :limit="5"
   :on-finished="onFinished">
  </my-upload>
  <button @click="upload" class="btn btn-xs btn-primary">Upload</button>
 </p>
</template>

<script>
import myUpload from &#39;./components/my-upload&#39;
export default {
 name: &#39;test&#39;,
 data(){
  return {
  fileList: [],//上传文件列表，无论单选还是支持多选，文件都以列表格式保存
  param: {param1: &#39;&#39;, param2: &#39;&#39; },//携带参数列表
  }
 },
 methods: {
  onChange(fileList){//监听文件变化，增减文件时都会被子组件调用
  this.fileList = [...fileList];
  },
  uploadSuccess(index, response){//某个文件上传成功都会执行该方法，index代表列表中第index个文件
  console.log(index, response);
  },
  upload(){//触发子组件的上传方法
  this.$refs.myUpload.submit();
  },
  removeFile(index){//移除某文件
  this.$refs.myUpload.remove(index);
  },
  uploadProgress(index, progress){//上传进度，上传时会不断被触发，需要进度指示时会很有用
  const{ percent } = progress;
  console.log(index, percent);
  },
  uploadFailed(index, err){//某文件上传失败会执行，index代表列表中第index个文件
  console.log(index, err);
  },
  onFinished(result){//所有文件上传完毕后（无论成败）执行，result: { success: 成功数目, failed: 失败数目 }
  console.log(result);
  }
 },
 components: {
  myUpload
 }
}
</script>

<template>
<p>
 <input style="display:none" @change="addFile" :multiple="multiple" type="file" :name="name" id="my-upload"/>
</p>
</template>

<script>
export default {
 name: &#39;my-upload&#39;,
 props: {
 name: String,
 action: {
  type: String,
  required: true
 },
 fileList: {
  type: Array,
  default: []
 },
 data: Object,
 multiple: Boolean,
 limit: Number,
 onChange: Function,
 onBefore: Function,
 onProgress: Function,
 onSuccess: Function,
 onFailed: Function,
 onFinished: Function
 },
 methods: {}//下文主要是methods的介绍，此处先省略
}
</script>

methods: {
  addFile, remove, submit, checkIfCanUpload
}

addFile({target: {files}}){//input标签触发onchange事件时，将文件加入待上传列表
 for(let i = 0, l = files.length; i < l; i++){
 files[i].url = URL.createObjectURL(files[i]);//创建blob地址，不然图片怎么展示？
 files[i].status = &#39;ready&#39;;//开始想给文件一个字段表示上传进行的步骤的，后面好像也没去用......
 }
 let fileList = [...this.fileList];
 if(this.multiple){//多选时，文件全部压如列表末尾
 fileList = [...fileList, ...files];
 let l = fileList.length;
 let limit = this.limit;
 if(limit && typeof limit === "number" && Math.ceil(limit) > 0 && l > limit){//有数目限制时，取后面limit个文件
  limit = Math.ceil(limit);
//  limit = limit > 10 ? 10 : limit;
  fileList = fileList.slice(l - limit);
 }
 }else{//单选时，只取最后一个文件。注意这里没写成fileList = files;是因为files本身就有多个元素（比如选择文件时一下子框了一堆）时，也只要一个
 fileList = [files[0]];
 }
 this.onChange(fileList);//调用父组件方法，将列表缓存到上一级data中的fileList属性
 },

remove(index){
 let fileList = [...this.fileList];
 if(fileList.length){
 fileList.splice(index, 1);
 this.onChange(fileList);
 }
},

submit(){
 if(this.checkIfCanUpload()){
 if(this.onProgress && typeof XMLHttpRequest !== 'undefined')
  this.xhrSubmit();
 else
  this.fetchSubmit();
 }
},

fetchSubmit(){
 let keys = Object.keys(this.data), values = Object.values(this.data), action = this.action;
 const promises = this.fileList.map(each => {
 each.status = "uploading";
 let data = new FormData();
 data.append(this.name || 'file', each);
 keys.forEach((one, index) => data.append(one, values[index]));
 return fetch(action, {
  method: 'POST',
  headers: {
   "Content-Type" : "application/x-www-form-urlencoded"
  },
  body: data
 }).then(res => res.text()).then(res => JSON.parse(res));//这里res.text()是根据返回值类型使用的，应该视情况而定
 });
 Promise.all(promises).then(resArray => {//多线程同时开始，如果并发数有限制，可以使用同步的方式一个一个传，这里不再赘述。
 let success = 0, failed = 0;
 resArray.forEach((res, index) => {
  if(res.code == 1){
  success++;         //统计上传成功的个数，由索引可以知道哪些成功了
  this.onSuccess(index, res);
  }else if(res.code == 520){   //约定失败的返回值是520
  failed++;         //统计上传失败的个数，由索引可以知道哪些失败了
  this.onFailed(index, res);
  }
 });
 return { success, failed };   //上传结束，将结果传递到下文
 }).then(this.onFinished);      //把上传总结果返回
},