Natural Sort for Datgridview

Question

I have a datagrid with a column that allows entry by the user of strings which may contain numbers. The column I have made sorted programmatically and one other automatically. I have looked at all available information on this and other websites but have found nothing that works or in some cases that I am able to know how to implement. Many of the solutions use Icomparer but few are specifically for datagridview. This is an example of the column data after performing datagridview1.Sort(Column1, ListSortDirection.Ascending);

1
140
2b
40
70
7a
9
aa
aa30
aa5
bc
de

I have introduced the MyDatagridHelper Class and relevant code using the solution from this site: C#: Custom sort of DataGridView, but alas it gives the following results

aa
bc
de
aa30
2b
7a
70
1
40
140
9
aa5

All other solutions are not specific to datagridview. I am self taught and relatively new to coding, so I am not able to make sense of the code within. I have tried as best I can to find commonality and cut and paste but to no avail. Some examples I thought showed promise and might do the job were: https://www.codeproject.com/articles/22517/natural-sort-comparer and Natural Sort Order in C#

I effectively need help on how to implement these or any other solutions that might do the job. I have not included the second column for simplicity as it is not relevant to the question. Thanks

Answer 1

The code project article 22517 that you link to has the logic in there that you require, it just needs some tweaking for use with a DataGridView by creating an implementation of System.Collections.IComparer rather than System.Collections.Generic.Comparer

So if you create yourself a new class in your project something like this:

public class NaturalSortComparer : System.Collections.IComparer {

    private System.Collections.Generic.Dictionary<string, string[]> table;

    public NaturalSortComparer() {
        table = new System.Collections.Generic.Dictionary<string, string[]>();
    }

    public void Dispose() {
        table.Clear();
        table = null;
    }

    public int Compare(object x, object y) {
        System.Windows.Forms.DataGridViewRow DataGridViewRow1 = (System.Windows.Forms.DataGridViewRow)x;
        System.Windows.Forms.DataGridViewRow DataGridViewRow2 = (System.Windows.Forms.DataGridViewRow)y;

        string xStr = DataGridViewRow1.Cells["Column1"].Value.ToString();
        string yStr = DataGridViewRow2.Cells["Column1"].Value.ToString();


        if (xStr == yStr) {
            return 0;
        }
        string[] x1, y1;
        if (!table.TryGetValue(xStr, out x1)) {
            x1 = System.Text.RegularExpressions.Regex.Split(xStr.Replace(" ", ""), "([0-9]+)");
            table.Add(xStr, x1);
        }
        if (!table.TryGetValue(yStr, out y1)) {
            y1 = System.Text.RegularExpressions.Regex.Split(yStr.Replace(" ", ""), "([0-9]+)");
            table.Add(yStr, y1);
        }

        for (int i = 0; i < x1.Length && i < y1.Length; i++) {
            if (x1[i] != y1[i]) {
                return PartCompare(x1[i], y1[i]);
            }
        }
        if (y1.Length > x1.Length) {
            return 1;
        } else if (x1.Length > y1.Length) {
            return -1;
        } else {
            return 0;
        }
    }

    private static int PartCompare(string left, string right) {
        int x, y;
        if (!int.TryParse(left, out x)) {
            return left.CompareTo(right);
        }

        if (!int.TryParse(right, out y)) {
            return left.CompareTo(right);
        }

        return x.CompareTo(y);
    }
}

You can see in here that I have hard coded it to used a column named "Column1" as per your example, but you can change this to be more dynamic.

When you then sort your grid, you can pass in a new instance of this class you have just created, like this:

dataGridView1.Sort(new NaturalSortComparer());