blocked by CORS policy: Request header field token is not allowed by Access-Control-Allow-Headers in

uniapp cross-domain error:

blocked by CORS policy: Request header field token is not allowed by Access-Control-Allow-Headers in preflight response

The reason is that the token name is not set in the cross-domain settings. Just add the token to the cross-domain request header.

Before setting the token

//设置跨域访问（设置在所有的请求前面即可）
router.all("*", function (req, res, next) {
	//设置允许跨域的域名，*代表允许任意域名跨域
	res.header("Access-Control-Allow-Origin", "*");
	//允许的header类型,X-Requested-With
	res.header("Access-Control-Allow-Headers", "Content-Type");
    //跨域允许的请求方式 
	res.header("Access-Control-Allow-Methods", "DELETE,PUT,POST,GET,OPTIONS");
	// res.header("Access-Control-Allow-Methods", "*");
	res.header("Content-Type", "application/json;chartset=utf-8");
	// if (req.method == 'OPTIONS')
	// 	res.sendStatus(200); //让options尝试请求快速结束
	// else
		next();
});

After setting the token

//设置跨域访问（设置在所有的请求前面即可）
router.all("*", function (req, res, next) {
	//设置允许跨域的域名，*代表允许任意域名跨域
	res.header("Access-Control-Allow-Origin", "*");
	//允许的header类型,X-Requested-With
	res.header("Access-Control-Allow-Headers", "Appid,Secret,Access-Token,token,Content-Type,Origin,User-Agent,DNT,Cache-Control,X-Requested-With");
    //跨域允许的请求方式 
	res.header("Access-Control-Allow-Methods", "DELETE,PUT,POST,GET,OPTIONS");
	// res.header("Access-Control-Allow-Methods", "*");
	res.header("Content-Type", "application/json;chartset=utf-8");
	// if (req.method == 'OPTIONS')
	// 	res.sendStatus(200); //让options尝试请求快速结束
	// else
		next();
});

Compare the differences

"Access-Control-Allow-Headers", "Content-Type,token"

Just add token to solve the problem. Similarly, if you need other request headers, just add them separated by commas.