我试图得到一个简单的文件上传机制的工作与快车4.0，但我不断收到undefined对req.files在app.post体内。以下是相关代码：

var bodyParser = require('body-parser');
var methodOverride = require('method-override');
//...
app.use(bodyParser({ uploadDir: path.join(__dirname, 'files'), keepExtensions: true })); 
app.use(methodOverride()); 
//...
app.post('/fileupload', function (req, res) {
  console.log(req.files); 
  res.send('ok'); 
});

..和随附的帕格代码：

form(name="uploader", action="/fileupload", method="post", enctype="multipart/form-data")
    input(type="file", name="file", id="file")
    input(type="submit", value="Upload")

解决方案
由于以下mscdex的响应，我已切换为使用busboy而不是bodyParser：

var fs = require('fs');
var busboy = require('connect-busboy');
//...
app.use(busboy()); 
//...
app.post('/fileupload', function(req, res) {
    var fstream;
    req.pipe(req.busboy);
    req.busboy.on('file', function (fieldname, file, filename) {
        console.log("Uploading: " + filename); 
        fstream = fs.createWriteStream(__dirname + '/files/' + filename);
        file.pipe(fstream);
        fstream.on('close', function () {
            res.redirect('back');
        });
    });
});