使用js跨域请求资源时报错如下:
XMLHttpRequest cannot load https://en.wikipedia.org/w/api.php?format=json&action=query&generator=searc…racts&pilimit=max&exintro&explaintext&exsentences=1&exlimit=max&gsrsearch=. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'null' is therefore not allowed access.
具体想问什么呢?