How to sort multiple time and on specific text in c# win. form

You can't sort a DataTable except by using "simple" comparisons on the DataView: there is no built in mechanism for using a custom sort comparer.

So: extract the rows, sort them using Linq or similar, and put the rows back into the DataTable.
That way you can write a comparison method that works any way you need it to.


So...a sample:

    // Set up your sample data
    DataTable dt = new DataTable();
    dt.Columns.Add("Id");
    dt.Columns.Add("Name");
    dt.Rows.Add(1, "5% VAT");
    dt.Rows.Add(2, "12.5% CST");
    dt.Rows.Add(3, "12.5% VAT");
    dt.Rows.Add(4, "14% VAT");
    dt.Rows.Add(5, "2% CST");
    // Extract data to Enumerable
    List<string> list = new List<string>();
    foreach (DataRow row in dt.Rows)
        {
        list.Add((string)row["name"]);
        }
    // Order list
    list = list.OrderBy(s => s, new PercentageComparer()).ToList();
    // Put sorted data back in table
    for (int i = 0; i < dt.Rows.Count; i++)
        {
        dt.Rows[i][1] = list[i];
        }
    // And display
    myDataGridView.DataSource = dt;
    }


public class PercentageComparer : IComparer<string>
    {
    public int Compare(string x, string y)
        {
        string[] partsX = x.Split(' ');
        string[] partsY = y.Split(' ');
        if (partsX[1] == partsY[1])
            {
            // Same subgroup.
            // Return based on percentage
            double dx = double.Parse(partsX[0].Trim('%'));
            double dy = double.Parse(partsY[0].Trim('%'));
            if (dx < dy) return -1;
            if (dx > dy) return 1;
            return 0;
            }
        // Return based on subgroup
        // Note order of compare: VAT before CST...
        return string.Compare(partsY[1], partsX[1]);
        }
    }