从答案 Express-js无法获取我的静态文件，为什么？我会建议：

From the answer Express-js can't GET my static files, why? I'd suggest:

app.use("/client", express.static(__dirname + '/client'));

这是因为您的：

This is needed because your:

app.get ('/', function (req,res) {
res.render('index.html');
});

只能解决当有人前往 / $ c $时发生的情况c>并说应该提供index.html。这本身并不适用于其他任何事情。

is only addressing what happens when someone goes to / and saying that index.html should be served. That alone doesn't serve anything else.