Selecting values from the checkboxes inside the GridView control is pretty simple. Check out the code below.
// StringBuilder object
StringBuilder str = new StringBuilder();
// Select the checkboxes from the GridView control
for (int i = 0; i < GridView1.Rows.Count; i++)
{
GridViewRow row = GridView1.Rows[i];
bool isChecked = ((CheckBox) row.FindControl("chkSelect")).Checked;
if (isChecked)
{
// Column 2 is the name column
str.Append(GridView1.Rows[i].Cells[2].Text);
}
}
Checkout the complete article:
Selecting Checkboxes inside the GridView Control