Javascript 如何正确使用express fileupload

我正在尝试集成

express fileupload

以将图像上传到我的服务器。我遵循了此链接中提供的示例，但它不起作用。下面我只包含了与相关代码行相关的每个文件

index.ejs:相关行

<form method="post" action="/images" enctype="multipart/formdata">
    <div class="panel-body form-horizontal">
        <div class="form-group col-md-12">
            <label class="col-sm-2 control-label" for="file">Browse:</label>

            <div class="col-md-10">
                <input class="form-control" type="file" name="file" id="file">
            </div>
        </div>
    </div>
</form>

configure.js

const express = require('express');
const config = require('./server/configure');
let app = new express();

app.set('port', process.env.PORT || 3300);

app = config(app);

app.listen(app.get('port'), () => {
    console.log(`Server up: http://localhost:${app.get('port')}`);
});

const express = require('express');
const path = require('path');
const expressFileUpload = require('express-fileupload');
const routes = require('./routes');

module.exports = (app) => {

    // applying expressFileUpload middleware
    app.use(expressFileUpload());

    routes(app);

    app.use('/public/', express.static(path.join(__dirname, '../public')));
    return app;
};

const image = require('../controllers/image');

module.exports = (app) => {
    app.post('/images', image.create);
};

module.exports = {

    create(req, res) {
        let image = req.files.file;
    }
}

routes.js

const express = require('express');
const config = require('./server/configure');
let app = new express();

app.set('port', process.env.PORT || 3300);

app = config(app);

app.listen(app.get('port'), () => {
    console.log(`Server up: http://localhost:${app.get('port')}`);
});

const express = require('express');
const path = require('path');
const expressFileUpload = require('express-fileupload');
const routes = require('./routes');

module.exports = (app) => {

    // applying expressFileUpload middleware
    app.use(expressFileUpload());

    routes(app);

    app.use('/public/', express.static(path.join(__dirname, '../public')));
    return app;
};

const image = require('../controllers/image');

module.exports = (app) => {
    app.post('/images', image.create);
};

module.exports = {

    create(req, res) {
        let image = req.files.file;
    }
}

image.js

const express = require('express');
const config = require('./server/configure');
let app = new express();

app.set('port', process.env.PORT || 3300);

app = config(app);

app.listen(app.get('port'), () => {
    console.log(`Server up: http://localhost:${app.get('port')}`);
});

const express = require('express');
const path = require('path');
const expressFileUpload = require('express-fileupload');
const routes = require('./routes');

module.exports = (app) => {

    // applying expressFileUpload middleware
    app.use(expressFileUpload());

    routes(app);

    app.use('/public/', express.static(path.join(__dirname, '../public')));
    return app;
};

const image = require('../controllers/image');

module.exports = (app) => {
    app.post('/images', image.create);
};

module.exports = {

    create(req, res) {
        let image = req.files.file;
    }
}

错误

我在下面一行得到一个错误

let image=req.files.file哪些状态

TypeError:无法读取未定义的属性“文件”

为什么文件未定义？如何使用express fileunload正确上载图像？
节点js代码中没有问题。它工作正常。问题在HTML文件中

表单enctype必须是enctype=“多部分/表单数据”&而不是您添加的内容

以下是参考资料：
在使用文件上载和express时，我建议您使用

文件上传很棘手

当一个或多个文件“到达”服务器时，您可以使用两种不同的方法存储它们：

将文件保存到已知安全位置的磁盘
将文件保存在RAM内存中
这两种方法各有利弊。由你决定哪一个更适合你的需要

下面是我的服务器上的一个示例，用于处理用户配置文件映像的上载（GitHub项目链接：）。它是用typescript编写的，但语法几乎相同

文件中间件-FileMiddleware.ts

const express = require('express');
const config = require('./server/configure');
let app = new express();

app.set('port', process.env.PORT || 3300);

app = config(app);

app.listen(app.get('port'), () => {
    console.log(`Server up: http://localhost:${app.get('port')}`);
});

const express = require('express');
const path = require('path');
const expressFileUpload = require('express-fileupload');
const routes = require('./routes');

module.exports = (app) => {

    // applying expressFileUpload middleware
    app.use(expressFileUpload());

    routes(app);

    app.use('/public/', express.static(path.join(__dirname, '../public')));
    return app;
};

const image = require('../controllers/image');

module.exports = (app) => {
    app.post('/images', image.create);
};

module.exports = {

    create(req, res) {
        let image = req.files.file;
    }
}

用于处理磁盘和内存存储的中间件。我可以选择哪一条最适合特定的快速路线（中间件下的示例）

从“路径”导入路径；
从“multer”进口multer；
导出默认类FileMiddleware{
公共静态只读memoryLoader=multer({
存储：multer.memoryStorage（），
限制：{
文件大小：2097152，//2 MB
},
});
公共静态只读diskLoader=multer({
存储：multer.diskStorage({
目的地：（_请求，_文件，cb）=>{
cb（null，path.join（_dirname，'../tmp/upload'）；
},
}),
限制：{
文件大小：67108864，//64 MB
},
});
}

用户路由-User.ts

const express = require('express');
const config = require('./server/configure');
let app = new express();

app.set('port', process.env.PORT || 3300);

app = config(app);

app.listen(app.get('port'), () => {
    console.log(`Server up: http://localhost:${app.get('port')}`);
});

const express = require('express');
const path = require('path');
const expressFileUpload = require('express-fileupload');
const routes = require('./routes');

module.exports = (app) => {

    // applying expressFileUpload middleware
    app.use(expressFileUpload());

    routes(app);

    app.use('/public/', express.static(path.join(__dirname, '../public')));
    return app;
};

const image = require('../controllers/image');

module.exports = (app) => {
    app.post('/images', image.create);
};

module.exports = {

    create(req, res) {
        let image = req.files.file;
    }
}

用于处理化身文件上载的用户路由。您可以看到，我正在定义路径、文件中间件（在本例中是一个内存存储—由映像键标识的单个文件）以及用于处理该过程的控制器

从“express”导入{Router}；
从'@app/controller'导入{UserController}；
从'@app/middleware'导入{FileMiddleware}；
常量路由器=路由器（）；
转发器(
“/user/avatar”，
FileMiddleware.memoryLoader.single（'image'），
UserController.updateAvatar
);
导出默认路由器；

在控制器中，您可以使用req.file检索图像，就这么简单

正如我所说的使用Multer，配置和使用非常简单和直观

PS：记住，在表单中使用文件上载意味着添加enctype=“multipart/form data”