javascript - 如何将基本身份验证 header 分配给 XMLHTTPREQUEST？

Question

我已经阅读了很多关于预检和 CORS 的答案，所以请不要发布引用我应该阅读的内容的链接。许多答案都是从服务器的 Angular 出发的，但在这种情况下我是客户端。我是否设置原始 header ？我的假设是这是一个简单的请求，对吗？

 req.open("POST", url, true);
 req.setRequestHeader( 'Content-Type',   'application/blahblah' );
 req.setRequestHeader( 'Accept', 'application/blahblah' );
 req.setRequestHeader("Authorization", "Basic " + btoa(user + ":" + pass)); 
 req.send();

但它仍然无法正常工作，我的错误:

Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'null' is therefore not allowed access. The response had HTTP status code 500.

Answer 1

如果要设置授权头

req.setRequestHeader('Authorization','Basic ' + Base64StringOfUserColonPassword);