uniapp 使用原生new FormData()上传文件

<template>
	<view class="">
		<view class="upload-file" @click="uploadFile('zw')">
			<span>上传</span>
		</view>
		<view class="filelist" style="width: 100%;">
			<view class="fileEach" v-for="(item,index) in docFileList" :key="index">
					{{item.fileName}}
				<span class="preview" @click="deletes(item)">删除</span>
			</view>
		</view>
		<view ref="input" style="display:none" id="input" @change="referenceUpload()">
			<input type="file" value="" />
		</view>
	</view>
</template>

<script>
	export default {
		name: 'app',
		props: {},
		data() {
			return {
				docFileList:[]
			}
		},
		components: {},
		mounted() {},
		updated() {},
		methods: {
			uploadFile(){
				var inputfj = document.createElement('input')
				inputfj.type = 'file'
				document.querySelector("#inputfj").appendChild(inputfj)
				document.querySelector("#inputfj").lastChild.click()
			},
			referenceUpload(){
				this.getFileUpload(event)
				document.querySelector("#input").querySelector("input").value = null; // 多次上传相同文件，不能触发onchange
			},
			getFileUpload(e){
				var d = document.querySelector("#input").lastChild.files[0];
				if(this.docFileList && this.docFileList.length>0){
					// return uni.showToast({   //当只要求只上传一个文件时，可放开
					// 	icon: 'none',
					// 	title: '上传文件已存在,替换请先移除！'
					// })
					let file_names = this.docFileList.filter(v => {
						return v.fileName == d.name
					})
					if (file_names.length != 0) {
						return uni.showToast({
							icon: 'none',
							title: '请勿上传重复文件'
						})
					}
				}
				var attachType = ".doc,.docx,.pdf,.ofd,.png"  //可根据需求限制上传文件格式
				let a = attachType ? attachType.toLowerCase().split(",") : [];
				let name = d.name.substring(d.name.lastIndexOf(".")).toLowerCase();
				if (a.length > 0) {
					if (a.indexOf(name) < 0) {
						uni.showToast({
							icon: 'none',
							title:"只能上传" + attachType + "格式的文件"
						})
						return false;
					}
				}
				uni.showLoading({
					title: '上传中'
				});
				// 上传文件调接口,使用的是ajax
				var formData = new FormData();
				formData.append('file', d);
				var xhr = new XMLHttpRequest();
				xhr.open("post",uploadURl);   //uploadURl为上传文件的接口url地址
				//回调
				xhr.onreadystatechange = () => {
					uni.hideLoading();
					if (xhr.readyState == 4 && xhr.status == 200){
							let res = JSON.parse(xhr.responseText);
							this.docFileList = this.docFileList?this.docFileList:[]
							this.docFileList.push(...res.value)
							return false;
					}
				}
				//获取上传的进度
				xhr.upload.onprogress = (event) => {
						if(event.lengthComputable){
								var percent = event.loaded/event.total *100;
						}
				}
				//将formdata上传
				xhr.send(formData);
			},
			deletes(item){
				this.docFileList = this.docFileList.filter((v) => {
					return v.fileName !== item.fileName;
				});
			}
			
		}
	}
</script>

<style>
	.app {}
</style>