类型错误：无法读取未定义的属性“mv”

Question

I want to upload all type of files(ex: csv,html files), im using the below code but it throwing a error called

"Cannot read property 'mv' of undefined.."

Here is my code,

app.post('/file_upload', function (req, res) {
  if(req.files){
    let  file = req.files.file;
    file.mv('./Emailcsv/'+file,function(err,data){
      if(err){
        return  res.send("error occured")
      }
      else{
        console.log("saved");
        res.send("File uploaded")
      }
    })
  }
})

Here is my html code,

<div className="col-md-6" style={{marginTop:30}}>
<p>Hey There, Upload a HTML file here</p>
<form ref='uploadForm'
  id='uploadForm'
  action='/file_upload'
  method='post'
  encType="multipart/form-data">
    <input type="file" name="sampleFile" />
    <input type='submit' value='Upload!' />
</form>
</div>

Answer 1

You have to change the below line

let  file = req.files.file;

as,

let  file = req.files.sampleFile;

Hope this helps!

Answer 2

Cannot read property 'mv' of undefined..

显示此错误是因为文件未定义， console.log(req.files)并查看它包含的内容，然后如果您使用的是 multiform，也将值分配给文件，请查看express multer

Answer 3

req.files.file is of type UploadedFile | UploadedFile[] , so that means it could be a single file or an array. In this case, if you are sure that you only receive a single file, you can replace the variable declaration with this line:

let file = req.files.file as UploadedFile;