使用node.js上传图像文件

Question

我试图调整我的代码来上传文件，但我没有得到它，我在社区里看了看，我不明白，我仍然是新手。它总是落在json返回错误上，你知道它可能是什么吗?文件，其中包含逻辑

async img(request, response){
multer({
storage: multer.diskStorage({
destination: (req, file, cb) => {
cb(null, "./Uploads")
},
filename: (req, file, cb) => {
cb(null, Date.now().toString() + '-' + file.originalname)
},
fileFilter: (req, file, cb) => {
const extensionImg = ['image/png', 'image/jpg', 'image/jpeg'].find
(formatPermitted => formatPermitted == file.mimetype)
if(extensionImg){
return cb(null, true)
}
return cb(null, false)
} 
})
}).single('image')
if(request.file){
return response.status(200).json({erro: false, message: "ok"});
}else{
return response.status(400).json({erro: true, message: "error"});
}
} 

路由为

的文件

const IncidentsController = require('./controllers/IncidentsController');
const routes = express.Router();
routes.post('/uploads', IncidentsController.img)

Answer 1

multer(...).single(...)返回一个中间件函数。它返回的中间件函数必须被实际调用才能做一些事情。

通常，您将在请求处理程序之外定义中间件，然后将其用作一个或多个请求处理程序上的中间件。

const imgMulterMiddleware = multer({
storage: multer.diskStorage({
destination: (req, file, cb) => {
cb(null, "./Uploads")
},
filename: (req, file, cb) => {
cb(null, Date.now().toString() + '-' + file.originalname)
},
fileFilter: (req, file, cb) => {
const extensionImg = ['image/png', 'image/jpg', 'image/jpeg'].find
(formatPermitted => formatPermitted == file.mimetype)
if(extensionImg){
return cb(null, true)
}
return cb(null, false)
} 
})
}).single('image');

然后，根据需要使用中间件:

routes.post('/uploads', imgMulterMiddleware, (req, res) => {
// do something with req.file here which will be set
// by the middleware if it was successful
if (req.file) {
res.json({erro: false, message: "ok"});
} else {
res.status(400).json({erro: true, message: "error"});
}
});