如何设置静态文件的HTTP标头？

I use gin-gonic's r.Static("files", "./files") to serve all files in the files directory. Is there a way to set headers for these file requests so I can allow CORS?

There is an official Gin middleware providing this functionality.

A Good starting template (from their examples)

func main() {
    router := gin.Default()
    // - No origin allowed by default
    // - GET,POST, PUT, HEAD methods
    // - Credentials share disabled
    // - Preflight requests cached for 12 hours
    config := cors.DefaultConfig()
    config.AllowOrigins = []string{"http://google.com"}
    config.AddAllowOrigins("http://facebook.com")
    // config.AllowOrigins == []string{"http://google.com", "http://facebook.com"}

    router.Use(cors.New(config))
    router.Run()
}