how to get https image directory in subfolder image to view

how to get https image directory in subfolder image to storage in view list the code is below

It shown error in DirectoryInfo path

DirectoryInfo dir = new DirectoryInfo(System.Web.HttpContext.Current.Server.MapPath("http://www.blueocktopus.com/RRImages/all/"));

FileInfo[] file = dir.GetFiles();

List list = new List();

foreach (FileInfo file2 in file)

{

if (file2.Extension == ".png" || file2.Extension == ".jpg" || file2.Extension == ".jpeg")

{

list.Add(new string[] { "Imagespath" });

list.Add(new string[]{file2.ToString()});

}