app.js

const Koa = require('koa');
const Router = require('koa-router');
const router = new Router();
const app = new Koa();



router.all('*',function (ctx, next) {
    ctx.set('Access-Control-Allow-Origin', '*');
    ctx.set('Access-Control-Allow-Headers', 'Content-Type, Content-Length, Authorization, Accept, X-Requested-With , myheader');
    ctx.set('Access-Control-Allow-Methods', 'PUT, POST, GET, DELETE, OPTIONS');

    next();
  });


router.post('/api/test/', (ctx, next) => {
    ctx.body = {
        status: 'success'
    }
});

router.post('/api/test2/', (ctx, next) => {
    ctx.body = {
        status: 'success'
    }
});



app.use(router.routes()).use(router.allowedMethods());



app.listen(8089);


console.log('server start at 8089')

前端自定義頭部myheader

axios.post(`http://localhost:8089/api/test`, null, { headers: { 'myheader': 'test' }})
        .then(response => {
            console.log(response.data);
        });

后臺(tái)把所有的接口都設(shè)置成cors，前端是可以自定義頭部的。

但是如果我只是讓其中一個(gè)接口cors

const Koa = require('koa');
const Router = require('koa-router');
const router = new Router();
const app = new Koa();



router.post('/api/test/', (ctx, next) => {
    ctx.set('Access-Control-Allow-Origin', '*');
    ctx.set('Access-Control-Allow-Headers', 'Content-Type, Content-Length, Authorization, Accept, X-Requested-With , myheader');
    ctx.set('Access-Control-Allow-Methods', 'PUT, POST, GET, DELETE, OPTIONS');
    ctx.body = {
        status: 'success'
    }
});

router.post('/api/test2/', (ctx, next) => {
    ctx.body = {
        status: 'success'
    }
});



app.use(router.routes()).use(router.allowedMethods());



app.listen(8089);


console.log('server start at 8089')

這時(shí)前端設(shè)置自定義頭部，就會(huì)報(bào)錯(cuò)

說(shuō)沒(méi)有No 'Access-Control-Allow-Origin' header，但是我已經(jīng)設(shè)置過(guò)Access-Control-Allow-Headers了。

如果前端把自定義頭部去掉，這時(shí)又能跨域成功

// 正?？缬?axios.post(`http://localhost:8089/api/test`, null)
        .then(response => {
            console.log(response.data);
        });

求解決方法