高洛峰2017-04-17 14:56:11
The first impression is that the header has been sent. Then when you remove send in your callback, the header will be modified at 204 and 304. Show some code to see
巴扎黑2017-04-17 14:56:11
The error is reported because you have repeatedly set the response header. If you have something to search for, don’t ask questions when you don’t agree.