nginx 图片，js，css等文件允许跨域

location ~ .*\.(gif|jpg|jpeg|png|bmp|swf|flv|mp4|ico)$ {
#允许跨域请求
add_header Access-Control-Allow-Origin '*';
add_header Access-Control-Allow-Headers X-Requested-With;
add_header Access-Control-Allow-Methods GET,POST,OPTIONS; expires 30d;
access_log off;
}