Add new cloumn to exsit dataset

See more:

C#

ASP.NET

hi every body 
i have folder in my website where i can loop in it and get all files ordered i need to add anew column to an exist  data set  this my code 
 
string sourceDir = Server.MapPath("~/folder1/folder2/");
string[] fileEntries = Directory.GetFiles(sourceDir).OrderBy(filename => filename).ToArray();
foreach (string fileName in fileEntries)
{
string x = "<img src=\"" + Path.GetFileName(fileName) + "\" /><br />";
}
 
 this data set already have data i need to add anew colum to the same dataset with the image path from previous code
if (ds.Tables.Count > 0)
{
       // do something 
}
 
how it can be done

What I have tried:

string sourceDir = Server.MapPath("~/folder1/folder2/");
string[] fileEntries = Directory.GetFiles(sourceDir).OrderBy(filename => filename).ToArray();
foreach (string fileName in fileEntries)
{
string x = "<img src=\"" + Path.GetFileName(fileName) + "\" />
";
}

if (ds.Tables.Count > 0)
{
// do something
}

how it can be done