golang gin框架的文件下载

func FileDownload(c *gin.Context){
	c.Writer.Header().Add("Content-Disposition", fmt.Sprintf("attachment; filename=%s", filename))//fmt.Sprintf("attachment; filename=%s", filename)对下载的文件重命名
    c.Writer.Header().Add("Content-Type", "application/octet-stream")
	c.File("./file/a.txt")
}

它的核心是调用了http包    http.ServeFile(c.Writer, c.Request, filepath)

ServeFile  又调用了func serveFile(w ResponseWriter, r *Request, fs FileSystem, name string, redirect bool) 方法