跨域处理
//开放所有跨域 response.AddHeader("Access-Control-Allow-Origin", "*"); response.AddHeader("Access-Control-Allow-Credentials", "true"); response.AddHeader("Access-Control-Allow-Methods", "GET,POST,PUT,DELETE,OPTIONS"); response.AddHeader("Access-Control-Allow-Headers", "Accept,Origin,DNT,X-Mx-ReqToken,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Authorization");