ElementUI 上传文件以及限制

2022-04-30 07:29:11

一、概述

现有项目中，涉及文件上传。要求：

1. 文件必须是excel

2. 只能上传1个文件

3. 文件大小不能超过5M

二、Upload 上传

注意：ElementUI Upload 上传，需要和后端api结合才能使用。

演示环境使用django，版本为：3.1.5

新建django项目

新建django项目，项目名为upload_demo，app名为api

安装以下模块

Django==3.1.5
djangorestframework==3.11.1
django-cors-headers==3.5.0

以上是我环境的版本，这里不做强制要求，安装最新版本即可。

注意：django-cors-headers是用来解决跨域问题的。

修改upload_demo/settings.py

注册app

INSTALLED_APPS = [
    ‘django.contrib.admin‘,
    ‘django.contrib.auth‘,
    ‘django.contrib.contenttypes‘,
    ‘django.contrib.sessions‘,
    ‘django.contrib.messages‘,
    ‘django.contrib.staticfiles‘,
    ‘api.apps.ApiConfig‘,
    ‘rest_framework‘,
    ‘corsheaders‘,  # 注册应用cors
]

中间件增加

MIDDLEWARE = [
    ‘django.middleware.security.SecurityMiddleware‘,
    ‘django.contrib.sessions.middleware.SessionMiddleware‘,
    ‘django.middleware.common.CommonMiddleware‘,
    ‘django.middleware.csrf.CsrfViewMiddleware‘,
    ‘django.contrib.auth.middleware.AuthenticationMiddleware‘,
    ‘django.contrib.messages.middleware.MessageMiddleware‘,
    ‘django.middleware.clickjacking.XFrameOptionsMiddleware‘,
    ‘corsheaders.middleware.CorsMiddleware‘, # 注册组件cors
]

最后一行增加

#跨域增加忽略
CORS_ALLOW_CREDENTIALS = True
CORS_ORIGIN_ALLOW_ALL = True
# CORS_ORIGIN_WHITELIST = (
#     ‘http://‘,
# )

CORS_ALLOW_METHODS = (
    ‘DELETE‘,
    ‘GET‘,
    ‘OPTIONS‘,
    ‘PATCH‘,
    ‘POST‘,
    ‘PUT‘,
    ‘VIEW‘,
)

CORS_ALLOW_HEADERS = (
    ‘XMLHttpRequest‘,
    ‘X_FILENAME‘,
    ‘accept-encoding‘,
    ‘authorization‘,
    ‘content-type‘,
    ‘dnt‘,
    ‘origin‘,
    ‘user-agent‘,
    ‘x-csrftoken‘,
    ‘x-requested-with‘,
    ‘Pragma‘,
)

修改api/views.py，增加视图函数

from rest_framework.views import APIView
from upload_demo import settings
from django.shortcuts import render, redirect, HttpResponse
from django.http import JsonResponse
from rest_framework import status
import os
import uuid


class File(APIView):
    def post(self, request):
        print(request.FILES)
        # 接收文件
        file_obj = request.FILES.get(‘file‘, None)
        print("file_obj", file_obj.name)

        # 判断是否存在文件夹
        head_path = os.path.join(settings.BASE_DIR,‘upload‘)
        print("head_path", head_path)
        # 如果没有就创建文件路径
        if not os.path.exists(head_path):
            os.makedirs(head_path)

        # 判断文件大小不能超过5M
        if file_obj.size > 5242880:
            return JsonResponse({‘status‘: status.HTTP_403_FORBIDDEN, ‘msg‘: ‘文件过大‘},
                                status=status.HTTP_403_FORBIDDEN)

        # 文件后缀
        suffix = file_obj.name.split(".").pop()
        print("文件后缀", suffix)  # 图片后缀 png

        # 判断文件后缀
        suffix_list = ["xlsx","xls"]
        if suffix not in suffix_list:
            return JsonResponse({‘status‘: status.HTTP_403_FORBIDDEN, ‘msg‘: ‘只能选择excel文件‘},
                                status=status.HTTP_403_FORBIDDEN)

        # 重命名文件名
        file_name = ‘%s.%s‘%(uuid.uuid4(),suffix)
        print("file_name",file_name)
        # 储存路径
        file_path = os.path.join(head_path,file_name)
        print("储存路径", file_path)

        # 写入文件到指定路径
        with open(file_path, ‘wb‘) as f:
            for chunk in file_obj.chunks():
                f.write(chunk)

        data = {}
        data[‘name‘] = file_name
        return JsonResponse({‘status‘: status.HTTP_200_OK, ‘data‘: data}, status=status.HTTP_200_OK)

View Code

修改upload_demo/urls.py

from django.contrib import admin
from django.urls import path
from api import views

urlpatterns = [
    path(‘admin/‘, admin.site.urls),
    path(‘file/excel_upload/‘,views.File.as_view())
]

启动django项目，访问链接为：http://127.0.0.1:8000/

新建vue测试页

安装axios

npm install axios --save

test.vue

<template>
  <div style="width: 70%;margin-left: 30px;margin-top: 30px;">
    <el-upload ref="upload"
               class="upload-demo" :multiple=‘false‘ :auto-upload=‘true‘ list-type=‘text‘ :show-file-list=‘true‘
               :before-upload="beforeUpload" :drag=‘true‘ action=‘‘ :limit="1" :on-exceed="handleExceed"
               :http-request="uploadFile" accept=".xlsx" >
      <i class="el-icon-upload"></i>
      <div class="el-upload__text"><em>点击上传,仅限excel文件</em></div>
      <!--        <div class="el-upload__tip" slot="tip">仅限excel文件</div>-->
    </el-upload>
    <el-button type="primary" @click="onSubumit">提交</el-button>
  </div>
</template>

<script>
  // 导入模块
  import axios from ‘axios‘
  export default {
    components: {
      axios
    },
    data() {
      return {
        isUpload:false,  // 是否上传文件
      }
    },
    mounted: function() {
    },
    methods: {
      // 上传文件之前的钩子
      beforeUpload(file) {
        //判断文件格式
        let hz = file.name.split(‘.‘).pop()
        // console.log("hz",hz)
        if (hz != ‘xlsx‘ && hz != ‘xls‘) {
          this.$message.error(`只能选择excel文件`)
          return false
        }

        // 判断文件大小
        let fileSize = file.size / 1024 / 1024 < 5
        if (!fileSize) {
          this.$message.error(‘上传文件大小不能超过 5MB‘)
          return false
        }

        this.isUpload = true
      },
      // 上传文件个数超过定义的数量
      handleExceed(files, fileList) {
        this.$message.warning(`当前限制选择 1 个文件，请删除后继续上传`)
      },

      // 上传文件
      uploadFile(item) {
        let _this = this
        let fileObj = item.file
        const form = new FormData()// FormData 对象
        form.append(‘file‘, fileObj)// 文件对象  ‘upload‘是后台接收的参数名
        axios({
          url: ‘http://127.0.0.1:8000/file/excel_upload/‘,
          data: form,
          method: ‘POST‘,
          contentType: ‘multipart/form-data‘,
          processData: false //告诉jquery不要对form进行处理
          // contentType: false, //指定为false才能形成正确的Content-Type
        })
          .then(function(res) {
            // console.log(‘上传成功‘, res)
            // console.log("上传路径",res.data.excel_file_path)
            _this.$message.success("上传成功")
          })
          .catch(function(err) {
            let res = err.response
            // console.log(‘失败‘, res)
            _this.$message.error(res.data.msg)
          })
      },
      // 检查是否上传
      onSubumit(){
        if (this.isUpload == false){
          this.$message.error("请上传excel文件")
          return false
        } else {
          this.$message.success("文件已上传")
          return true
        }
      },
    }
  }
</script>

<style>
</style>