vue2elementui大文件切片

对于大文件切片，可以使用Vue.js和ElementUI来实现。以下是一个简单的示例：

1. 安装必要的库：

npm install --save element-ui vue-axios axios

2. 创建一个上传组件：

<template>
  <div>
    <el-upload
      :headers="headers"
      :data="uploadData"
      :action="uploadUrl"
      :on-change="handleChange"
      :on-success="handleSuccess"
      :on-error="handleError"
      :file-list="fileList"
      multiple>
      <el-button size="small" type="primary">点击上传</el-button>
    </el-upload>
  </div>
</template>

<script>
import { Upload, Button } from 'element-ui';
import axios from 'axios';

export default {
  components: {
    [Upload.name]: Upload,
    [Button.name]: Button
  },
  data() {
    return {
      uploadUrl: 'http://your-upload-url.com',
      headers: {
        Authorization: 'Bearer ' + localStorage.getItem('token')
      },
      uploadData: {
        // 可以添加其他的上传参数
      },
      fileList: []
    };
  },
  methods: {
    handleChange(file) {
      // 处理上传前的操作
    },
    handleSuccess(response, file) {
      // 处理上传完成后的操作
    },
    handleError(error, file) {
      // 处理上传失败的操作
    }
  }
};
</script>

3. 在 `handleChange` 方法中，可以使用 `FileReader` 来读取文件并进行切片，然后使用 `axios` 发送分片文件到服务器：

handleChange(file) {
  const chunkSize = 2 * 1024 * 1024; // 2MB
  const chunks = Math.ceil(file.size / chunkSize);
  const promises = [];
  for (let i = 0; i < chunks; i++) {
    const start = i * chunkSize;
    const end = Math.min(file.size, start + chunkSize);
    const blob = file.slice(start, end);
    const formData = new FormData();
    formData.append('file', blob);
    formData.append('fileName', file.name);
    formData.append('chunkNumber', i + 1);
    formData.append('totalChunks', chunks);
    formData.append('chunkSize', chunkSize);
    promises.push(axios.post('http://your-upload-url.com', formData, {
      headers: {
        Authorization: 'Bearer ' + localStorage.getItem('token')
      }
    }));
  }
  Promise.all(promises)
    .then(response => {
      // 所有分片上传完成的操作
    })
    .catch(error => {
      // 处理上传失败的操作
    });
}

4. 在服务器端，可以将上传的分片文件保存到临时文件夹中，然后在所有分片上传完成后，将它们合并成一个完整的文件：

const fs = require('fs');
const path = require('path');
const Busboy = require('busboy');

const tempDir = path.join(__dirname, 'temp');

// 创建临时文件夹
if (!fs.existsSync(tempDir)) {
  fs.mkdirSync(tempDir);
}

// 上传分片文件
app.post('/upload', (req, res) => {
  const busboy = new Busboy({ headers: req.headers });
  const formData = {};
  busboy.on('file', (fieldName, file, fileName, encoding, mimeType) => {
    const chunkNumber = Number(req.body.chunkNumber);
    const totalChunks = Number(req.body.totalChunks);
    const chunkSize = Number(req.body.chunkSize);
    const tempFilePath = path.join(tempDir, fileName + '-' + chunkNumber);
    file.pipe(fs.createWriteStream(tempFilePath));
    file.on('end', () => {
      formData[fieldName] = {
        fileName,
        tempFilePath,
        chunkNumber,
        totalChunks,
        chunkSize
      };
      console.log(`File ${fileName} chunk ${chunkNumber} uploaded`);
    });
  });
  busboy.on('field', (fieldName, fieldValue) => {
    formData[fieldName] = fieldValue;
  });
  busboy.on('finish', () => {
    console.log('All files uploaded');
    const chunks = Array.from({ length: formData['totalChunks'] }, (_, i) => i + 1);
    const promises = chunks.map(chunkNumber => {
      const tempFilePath = formData['fileName'] + '-' + chunkNumber;
      return fs.promises.readFile(path.join(tempDir, tempFilePath));
    });
    Promise.all(promises)
      .then(chunks => {
        const filePath = path.join(__dirname, 'uploads', formData['fileName']);
        fs.writeFileSync(filePath, Buffer.concat(chunks));
        console.log(`File ${formData['fileName']} uploaded successfully`);
        res.sendStatus(200);
      })
      .catch(error => {
        console.error(error);
        res.sendStatus(500);
      });
  });
  req.pipe(busboy);
});

这样，就可以实现大文件切片上传了。当然，在实际应用中，还需要考虑更多的安全性、可靠性和性能方面的问题。