How to compare cells of one column for selected rows?

February 25, 2022

Hi everyone please i need you’re help if it’s possible:
i have a DGV with 8 columns i want to compare all cells of second column "Fournisseur" whene rows are selected.

image1: selected rows have the same value of second column "Tramauto"="Tramauto"
image2: selected rows have differents values of sec column 1row "Tramauto"= 3row "Tramauto" but 2row different "Sonasid"

private void button13_Click(object sender, EventArgs e)
    {
      foreach (DataGridViewRow row in commandeDataGridView.SelectedRows)
            {
                 if(//selected rows have the same value of second column)
                    {do function}

               else
            {

                string message = "shoose the same Fournisseur";
                string title = "Error";
                MessageBox.Show(message,title);
            }

Thank you so much for you’re help!

>Solution :

You could use:

List<string> allCol2Values = commandeDataGridView.SelectedRows.Cast<DataGridViewRow>()
    .Select(r => r.Cells[1].Value?.ToString())
    .ToList();
string first = allCol2Values.FirstOrDefault();
bool allSame = allCol2Values.Skip(1).All(s => s == first);

If you don’t want to use LINQ, this is the classic loop way:

bool allSame = true;
string firstValue = null;
foreach (DataGridViewRow row in commandeDataGridView.SelectedRows)
{
    string col2Value = row.Cells[1].Value?.ToString();
    if (firstValue == null) firstValue = col2Value;
    if(col2Value != firstValue)
    {
        allSame = false;
        break;
    }
}