（1）上传个人信息

//package.json
{
  "name": "11.15-fileupload",
  "version": "1.0.0",
  "main": "index.js",
  "license": "MIT",
  "dependencies": {
    "koa": "^2.13.4",
    "koa-body": "^4.2.0",
    "koa-router": "^10.1.1",
    "koa-static": "^5.0.0"
  }
}

//add.html
//引入外部样式
<link rel="stylesheet" href="http://cdn.bootcss.com/bootstrap/3.3.0/css/bootstrap.min.css">
    <div class="container">
        <form action="http://localhost:5000/file" method="POST" role="form" enctype="multipart/form-data">
            <legend>添加小组成员</legend>
            <div class="form-group">
                <label for="">姓名</label>
                <input type="text" class="form-control" name="username" placeholder="name">
            </div>
            <div class="form-group">
                <label for="">年龄</label>
                <input type="text" class="form-control" name="age" placeholder="age">
            </div>
            <div class="form-group">
                <label for="">上传图像</label>
                <input type="file" class="form-control" name="logo" placeholder="Input field">
            </div>
            <button type="submit" class="btn btn-primary">添加数据</button>
        </form>
    </div>

//index.js
const koa = require("koa");
const app = new koa();
const router = require("koa-router")();
const static = require("koa-static");
const koaBody = require("koa-body");
const path = require("path");
const fs = require("fs");
router.get("/",async ctx=>{
    ctx.body= "连接成功"
})
router.post("/file",async ctx=>{
    /* name,age */
    console.log(ctx.request.body)
    // console.log(ctx.request.files.logo.path)
    var logo = ctx.request.files.logo.path;
    /* 1、创建一个可读流 */
    var reader = fs.createReadStream(logo);
    /* 2、获取上传图片所在的路径和扩展名 */
    // console.log(path.basename(logo))
    var uploadFile =  `./static/${path.basename(logo)}`;
    /* 3、创建一个可写流 */
    var writer = fs.createWriteStream(uploadFile);
    /* 4、将可读流通过管道写入可写流 */
    reader.pipe(writer);
    console.log(ctx.origin+"/"+path.basename(logo))
    ctx.body = "文件上传成功"
})
app.use(koaBody({
    multipart: true,
    formidable: {
        maxFileSize: 200 * 1024 * 1024,
        keepExtensions: true
    }
}))
app.use(router.routes());
app.use(static(path.join(__dirname,"static")))
app.listen(5000)