如何将 headers 设置为 Koa.js 中的所有响应?

How do I set headers to all responses in Koa.js?

在Express.js我曾经有过这样的代码:

app.use((req, res, next) => {
  res.header('Access-Control-Allow-Origin', '*');
  res.header('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept');
  res.header('Access-Control-Allow-Methods', 'POST, GET, PUT, DELETE, OPTIONS');
  next();
});

如何用 Koa.js 做同样的事情?我需要为每个服务器响应预设这几个http headers。

终于找到方法了。

app.use(async (ctx, next) => {
  ctx.set('Access-Control-Allow-Origin', '*');
  ctx.set('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept');
  ctx.set('Access-Control-Allow-Methods', 'POST, GET, PUT, DELETE, OPTIONS');
  await next();
});