Sorting DataTable-columns

Question

I have a datatable something like this:

     |  Col1  |  Col6  |  Col3  |  Col43 |  Col0  |
---------------------------------------------------
RowA |   1    |    6   |   54   |    4   |   123  |

As you see, the Cols are not sorted by their numbers. That is what I want it to look like after the "magic":

     |  Col0  |  Col1  |  Col3  |  Col6  |  Col43 |
---------------------------------------------------
RowA |   123  |    1   |   54   |    6   |    4   |

Is there a built-in function for such things in C#? And if not, how could I get started with this?

Answer 1

You'll probably need to implement your IComparer<T>, as "natural" order would be: Col0, Col1, Col3, Col43 and Col6. ("4" comes before "6")

Answer 2

You don't need to sort the columns in the DataTable object, just copy the column names to an array and sort the array. Then use the array to access the column values in the right order.

Sample:

class Program
    {
        static void Main(string[] args)
        {
            var dt = new DataTable { Columns = { "A3", "A2", "B1", "B3", "B2", "A1" } };
            dt.BeginLoadData();
            dt.Rows.Add("A3val", "A2val", "B1val", "B3val", "B2val", "A1val");
            dt.EndLoadData();

            string[] names=new string[dt.Columns.Count];
            for (int i = 0; i < dt.Columns.Count;i++ )
            {
                names[i] = dt.Columns[i].ColumnName;
            }
            Array.Sort(names);

            foreach (var name in names)
            {
                Console.Out.WriteLine("{0}={1}", name, dt.Rows[0][name]);
            }
            Console.ReadLine();
        }

Answer 3

You can do the column sorting in the table itself:

dt.Columns["Col0"].SetOrdinal(0);
dt.Columns["Col1"].SetOrdinal(1);
dt.Columns["Col2"].SetOrdinal(2);