Multer nodejs-要求。文件未定义

Question

我正在创建一个应用程序，使用Node、Express、ejs和multer上传图像。每次我提交表格时。文件未定义。我花了一整天的时间来排除故障，但却不知道自己做错了什么。

超文本标记语言

<form action="/post" id="formPost" method="post" enctype="multipart/form-data">
     <input class="img-file" type="file" name="image" required>
     <input class="submit" type="submit" value="Post" />
</form>

app.js

const path = require('path');
const express = require('express');
const morgan = require('morgan');
const bodyParser = require("body-parser");
const multer = require('multer');
const app = express();

app.use(express.static(path.join(__dirname, 'public')))
app.set('view engine', 'ejs'); 
app.set('views', path.join(__dirname,'resources/views'));
app.use(bodyParser.json());   
app.use(bodyParser.urlencoded({ extended: true }));

const storage = multer.diskStorage({
  destination: function (req, file, cb) {
    cb(null, "./image");
  },
  filename: function (req, file, cb) {
    console.log(req.file);

    cb(null, Date.now() + "-" + file.fieldname + ".png");
  },
});
const upload = multer({ storage: storage });
app.post("/post", upload.single("image"), (req, res) => {
      console.log(req.file);
});
app.get("/post", (req, res) => {
  res.render("post");
});
app.listen(, () => {
  console.log(`Example app listening at http://localhost:3000/login`);
});

Answer 1

您有一些小错误：首先，您忘记添加端口，而不是登录，应该是发布，然后我们立即找到正确的地址，避免出现错误

app.listen(3000, () => {
  console.log(`Example app listening at http://localhost:3000/post`);
});

项目文件夹

app.js我添加了一个简单的错误处理程序：

app.post("/post", upload.single("image"), (req, res, next) => {}

const path = require("path");
const express = require("express");
const morgan = require("morgan");
const bodyParser = require("body-parser");
const multer = require("multer");
const app = express();

app.use(express.static(path.join(__dirname, "public")));
app.set("view engine", "ejs");
app.set("views", path.join(__dirname, "resources/views"));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));

const storage = multer.diskStorage({
  destination: function (req, file, cb) {
    cb(null, "./image");
  },
  filename: function (req, file, cb) {
    console.log(req.file);

    cb(null, Date.now() + "-" + file.fieldname + ".png");
  },
});
const upload = multer({ storage: storage });

// app.post("/post", upload.single("image"), (req, res) => {
//   console.log(req.file);
// });

app.post("/post", upload.single("image"), (req, res, next) => {
  const file = req.file;
  if (!file) {
    const error = new Error("Please upload a file");
    error.httpStatusCode = 400;
    return next(error);
  }
  res.send(file);
  console.log("Success", req.file);
});

app.get("/post", (req, res) => {
  res.render("post");
});

app.listen(3000, () => {
  console.log(`Example app listening at http://localhost:3000/post`);
});

邮递ejs公司

<form action="/post" id="formPost" method="post" enctype="multipart/form-data">
  <input class="img-file" type="file" name="image" required />
  <input class="submit" type="submit" value="Upload File" />
</form>

输出：

选择文件并按上传文件后：

VSCode输出：

作品像一个魅力；-）