Checkboxes in a DataGridView

Hi all, me again with a newbie question.

I have this DataGridView with columns binding to a table, and then a
column with checkboxes that is not binding. I use this kind of column
for the user to select wich rows do delete, change, etc.

I have a button that makes the select all for the checkboxes and have
this code:

for (int i = 0; i < DataGridView.Rows.Count; i++)
{
DataGridView.Rows[i].Cells["clCheckBox"].Value = 1;
}


The problem is that i have kind of 70.000 records and the time to run
this is very long, is there a faster way?


Thanks a lot