I have found my solution. here is the code for the same
private void btnDelete_Click(object sender, EventArgs e)
{
foreach (DataGridViewRow Row in DataGridView1.Rows)
{
if (Row.Cells[0].Value != null)
{
if ((bool)(Row.Cells[0].Value) == true)
{
int tradeID = Convert.ToInt32(DataGridView1.Rows[Row.Index].Cells["ID"].Value.ToString());
}
}
}
loadDataGrid();
}