Try below code to bind directory information to GridView
var path = @"c:/";
var dirs = Directory.GetDirectories(path)
.Select(x => new DirectoryInfo(x))
.Select(x => new
{
Size = x.GetFiles().Sum(c => c.Length),
Name = Path.GetDirectoryName(x.Name),
Path = x.FullName
}).ToList();
Bind
dirs
object to GridView and use Size, Name and Path property to assign values.