显示 DataGridView 的已删除行的索引

Question

I want to show in a second column of my datagridview the index of the deleted rows.

private void btn_Verify_Click(object sender, EventArgs e)
        {
            var dataA = new HashSet<string>();
            var dataB = new HashSet<string>();
            var exceptA = dataA.Except(dataB);
            var exceptB = dataB.Except(dataA);
            for (int i = 1; i < dgv_A.Rows.Count; i++)
            {
                dataA.Add(dgv_A[8, i].Value.ToString());
            }
            for (int i = 1; i < dgv_B.Rows.Count; i++)
            {
                dataB.Add(dgv_B[8, i].Value.ToString());
            }
            if (dataA.SetEquals(dataB))
            {
                lbl_result.Text = "Certifications are correct";
            }
            else
            {
                lbl_result.Text = "Certifications are incorrect";

//A function is created as the DataGridView expects the object to generate the column.
                dgv_B.DataSource = exceptB.Select(s => new { Value = s }).ToList();
                dgv_A.DataSource = exceptA.Select(s => new { Value = s }).ToList();

                dgv_B.Columns[0].HeaderText = "Deleted Files from First Archive";
                dgv_A.Columns[0].HeaderText = "Deleted Files from Second Archive";
            }
        }

This is the result if the HashSets are unequal, I want to add a second column in each DataGridView with the index of the row removed, all ideas are welcome.

Answer 1

Im assuming the index you want to show is from where the item sat in the original list.

You can achieve this with minimal change by using a HashSet<(string, int)> to store the information and then using an annonymous class with two fields in the select

private void btn_Verify_Click(object sender, EventArgs e)
{
    var dataA = new HashSet<(string, int)>();
    var dataB = new HashSet<(string, int)>();
    var exceptA = dataA.Except(dataB);
    var exceptB = dataB.Except(dataA);
    for (int i = 1; i < dgv_A.Rows.Count; i++)
    {
        dataA.Add((dgv_A[8, i].Value.ToString(), i));
    }
    for (int i = 1; i < dgv_B.Rows.Count; i++)
    {
        dataB.Add((dgv_B[8, i].Value.ToString(), i));
    }
    if (dataA.SetEquals(dataB))
    {
        label1.Text = "Certifications are correct";
    }
    else
    {
        label1.Text = "Certifications are incorrect";

        //A function is created as the DataGridView expects the object to generate the column.
        dgv_B.DataSource = exceptB.Select(s => new { s.Item1, s.Item2 }).ToList();
        dgv_A.DataSource = exceptA.Select(s => new { s.Item1, s.Item2 }).ToList();

        dgv_B.Columns[0].HeaderText = "Deleted Files from First Archive";
        dgv_A.Columns[0].HeaderText = "Deleted Files from Second Archive";
    }
}

This being said I think you have a bug in your code to because your loops iterating over datagrids start at index 1 so you can never add the first item even if it is deleted - but thats not related to your question.