Question

I have a datagridview that I would like to have rows sorted based on the portion of a string entered from a user. The entered string is compared with all of the strings in a particular column. For instance, if I gave “comp” as the search word, the program would try to compare the search word with the strings on first column and sort the rows in a descending order which starts with “comp”, such as “compare”, “composition”, “computer” etc. Rest of the words that do not match is either left alone or sorted in an alphabetical order (whichever is easier).

In LINQ, I am aware that you can apply the following code to achieve what you wanted with a string array:

var sortedWords = words.Where(x => x.Contains("comp"))
                       .OrderByDescending(x => x);

How can I achieve the same thing in Datagridview as I need to have the rows sorted, not just the items inside a particular column?

Edit:

The following code is giving a System.InvalidOperationException. (SetCurrentCellAddressCore is being called twice)

    private void DGVPointCtrl_CellEndEdit(object sender, DataGridViewCellEventArgs e)
    {
        MatchComparer mc = new MatchComparer();
        DGVPointCtrl.Sort(mc); //Error
    }

I’m probably doing something wrong but I’m not sure why. Here is the code that programatically adds the rows for testing purposes:

private void BtnRefresh_Click(object sender, EventArgs e)
        {
            try
            {
                DGVPointCtrl.Rows.Clear();
                int mainIndex = CmbMainDevice.SelectedIndex;
                int subIndex = CmbSubDevice.SelectedIndex;
                DDCDAO ddcdao = new DDCDAO(DDCGlobal.ddcEngineIP, ddc.Ip);
                string pointListType;
                object rs;

                //Currently only supports IO DDC Request
                //TO DO: Change DDCDAO to send proper subdevice requests

                if (mainIndex == 0) //IO
                {
                    #region Main Device: IO
                }


                //First row is for searching items
                DGVPointCtrl.Rows.Add(new DataGridViewRow());
                for (int i = 1; i < 5; i++)
                {
                    DGVPointCtrl.Rows.Add(new DataGridViewRow());
                    DGVPointCtrl.Rows[i].ReadOnly = true;
                }
                DGVPointCtrl.Columns[0].SortMode = DataGridViewColumnSortMode.Programmatic;
                DGVPointCtrl.Rows[0].DefaultCellStyle.Font =
                new Font(DGVPointCtrl.DefaultCellStyle.Font, FontStyle.Italic | FontStyle.Bold);

                if (subIndex == 1) //BI
                {
                    PointDGVColumnGenerate("IO_BI");

                }
                else if (subIndex == 2) //BO
                {
                    PointDGVColumnGenerate("IO_BO");
                }
                else if (subIndex == 3) //AI
                {
                    PointDGVColumnGenerate("IO_AI");
                }
                else if (subIndex == 4) //AO
                {
                    PointDGVColumnGenerate("IO_AO");
                }

                DGVPointCtrl.Rows[1].Cells[0].Value = "IO12314";
                DGVPointCtrl.Rows[2].Cells[0].Value = "IO21948";
                DGVPointCtrl.Rows[3].Cells[0].Value = "IO28194";
                DGVPointCtrl.Rows[4].Cells[0].Value = "VP12984";
                DGVPointCtrl.Rows[2].Cells[1].Value = "asdf";

                #endregion
            }
            catch
            {
            }
      }

    private void PointDGVColumnGenerate(string key)
    {
        int colCount = 0;
        DGVColumnTable.Clear();

        for (int i = 0; i < COL_MAX; i++)
        {
            DGVPointCtrl.Columns[i].HeaderText = "   ";
            DGVPointCtrl.Columns[i].Visible = true;
        }

        foreach (string s in UIConstant.DDCPCtrlListColumnText[key])
        {
            DGVPointCtrl.Columns[colCount].HeaderText = s;
            DGVColumnTable.Add(DGVPointCtrl.Columns[colCount]);
            colCount++;
        }
    }

Edit2:

public class MatchComparer : IComparer
{
    private static IComparer defaultComparer = new CaseInsensitiveComparer();
    int IComparer.Compare(object x, object y)
    {
        DataGridViewRow xr = (DataGridViewRow)x;
        DataGridViewRow yr = (DataGridViewRow)y;

        string xs = "";
        string ys = "";
        try
        {
            xs = xr.Cells[0].Value.ToString();
        }
        catch
        {
        }
        try
        {
            ys = yr.Cells[0].Value.ToString();
        }
        catch
        {
        }

        if (HasMatch(xs) && !HasMatch(ys)) return -1;
        else if (!HasMatch(xs) && HasMatch(ys)) return 1;
        else return defaultComparer.Compare(xs, ys);
    }

Answer 1

This is possible only if you are populating the grid yourself as opposed to binding it to the database.

Set DataGridViewColumn.SortMode to Programmatic.

Use DataGridView.Sort to impose a comparer like this:

public class MatchComparer : IComparer  {
     int IComparer.Compare(object x, object y)  {
         if (HasMatch(x) && !HasMatch(y)) return -1;
         else if (!HasMatch(x) && HasMatch(y)) return 1;
         else return defaultComparer.Compare(x, y);
     }

     private bool HasMatch(object x) {
         return x is string && ((string)x).StartsWith("comp");
     }

     private static IComparer defaultComparer = new CaseInsensitiveComparer();
}