koa 允许跨域

1.安装模块

npm install koa2-cors --save

2.引用

const cors = require('koa2-cors');
...

// 允许跨域访问
app.use(cors({
  exposeHeaders: ['WWW-Authenticate', 'Server-Authorization', 'Date'],
  maxAge: 100,
  credentials: true,
  allowMethods: ['GET', 'POST', 'OPTIONS'],
  allowHeaders: ['Content-Type', 'Authorization', 'Accept', 'X-Custom-Header', 'anonymous'],
}));

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