Why is this code to paste into a DataGridView so slow?

string s = Clipboard.GetText().Replace(开发者_运维知识库"\r", " ");
string[] lines = s.Split('\n');
int row = dgView.CurrentCell.RowIndex;
int col = dgView.CurrentCell.ColumnIndex;
int linesCount = lines.Count();
if ((row + linesCount) - dgView.RowCount > 0) dgView.Rows.Add((row + linesCount) - dgView.RowCount);

asyncSqlResultsViewer.publicToolStripProgressBar.Maximum = linesCount;
asyncSqlResultsViewer.publicToolStripProgressBar.Step = 1;
asyncSqlResultsViewer.publicToolStripProgressBar.Visible = true;
dgView.ReadOnly = true;

foreach (string line in lines)
{
    if (line.Length > 0)
    {
        string[] cells = line.Split('\t');
        for (int i = 0; i < cells.GetLength(0); ++i)
        {
            if (col + i < dgView.ColumnCount)
            {
                dgView[col + i, row].Value = cells[i];
            }
            else
            {
                break;
            }
        }
        row++;
    }
    else
    {
        break;
    }
    asyncSqlResultsViewer.publicToolStripProgressBar.PerformStep();
}

It is ridiculously slow. Pasting 500 rows with 5 columns takes about 30 seconds. Please take into consideration that there might be already data in the DataGridView and I don't necessarily want to override it (it all depends on the starting cell). So I don't know how could I use a DataTable and assign it as DataSource in case you had that idea.

---

You should always suspend the layout before updating the grid:

dgView.SuspendLayout();
// Do updates here
dgView.ResumeLayout();

---

I had my AutoSizeColumnsMode set to AllCells. I need to set it to None when pasting. That makes a exponential difference. My 30 seconds now became less than half a second.