app.all(‘*‘, function (req, res, next) { ???res.header("Access-Control-Allow-Origin", "*"); ???res.header("Access-Control-Allow-Headers", "X-Requested-With"); ???res.header("Access-Control-Allow-Methods", "PUT,POST,GET,DELETE,OPTIONS"); ???res.header("X-Powered-By", ‘ 3.2.1‘); ???res.header("Content-Type", "application/json;charset=utf-8"); ???next();});
if (req.method === ‘OPTIONS‘) { ?????console.log(‘!OPTIONS‘); ?????var headers = {}; ?????// IE8 does not allow domains to be specified, just the * ?????// headers["Access-Control-Allow-Origin"] = req.headers.origin; ?????headers["Access-Control-Allow-Origin"] = "*"; ?????headers["Access-Control-Allow-Methods"] = "POST, GET, PUT, DELETE, OPTIONS"; ?????headers["Access-Control-Allow-Credentials"] = false; ?????headers["Access-Control-Max-Age"] = ‘86400‘; // 24 hours ?????headers["Access-Control-Allow-Headers"] = "X-Requested-With, X-HTTP-Method-Override, Content-Type, Accept"; ?????res.writeHead(200, headers); ?????res.end();} else {//...other requests}
“简单请求”
请求方法是以下三种方法之一：
????HEAD
????GET
????POST
“非简单请求”
HTTP的头信息不超出以下几种字段：
????Accept
????Accept-Language
????Content-Language
????Last-Event-ID
????Content-Type：
????????application/x-www-form-urlencoded、 multipart/form-data、text/plain
不满足这些特征的请求称为“非简单请求”，例如：content-type=applicaiton/json , method = PUT/DELETE...
nodejs 解决跨域
原文地址：https://www.cnblogs.com/tongbiao/p/9893249.html