//在请求头中添加"Access-Control-Allow-Origin: " const httpOptions = { headers: new HttpHeaders({ 'Content-Type': 'application/json', 'Access-Control-Allow-Origin': '' }) };
//安装CORS插件 npm install cors --save
//在app.js或server.js中引入CORS插件 var express = require('express'); var cors = require('cors'); var app = express();
app.use(cors());