Sorting data table by multiple columns using C#

Question

I have a Datatable with columns named foldername,documentname. Data as below:

FolderName  DocumentName
Folder1     HR[D] Document
Folder1     ___----'
Folder1     Asp_example.pdf
Folder2     SD
Folder3     Heavy_weight
Folder3     Accesorial Services

How to alphabetically sort DocumentName based on FolderName in .Net Framework 2.0.

Solution we tried is below but takes too many time as it contains more than 1200000 records.

int counter=0;

while (counter < searchDT.Rows.Count){
   string FolderName = Convert.ToString(searchDT.Rows[counter]["Folder Name"]);

   string exp = "[Folder Name] like '" + FolderName + "'";

   if (FolderName.Contains("%") || FolderName.Contains("_") || FolderName.Contains("[]") ||      FolderName.Contains("'"))

      exp = "[Folder Name] like '" + EscapeLikeValue(FolderName) + "'";

   string sortExpression = "[Document Name] ASC";

   DataRow[] drfoldername = searchDT.Select(exp, sortExpression);

   foreach (DataRow row in drfoldername)
     drfoldernameDT.ImportRow(row);

   counter += drfoldername.Length;

 }

Answer 1

DataTable dt = new DataTable();

DataView dv = new DataView(dt);
dv.Sort = "FolderName, DocumentName ASC";

Try that out. It will sort first for FolderName, then DocumentName.

If you need to send that to a component on the screen, you can do the same as you're doing with a DataTable.

Answer 2

Here was my solution to this problem:

Datatable FI = new Datatable();
DataView viewFI = new DataView(FI);
viewFI.Sort = "ServiceDate, ServiceRoute";
DataTable OFI= viewFI.ToTable();