जब डेटाग्रिडव्यू में सभी चेकबॉक्स पर क्लिक किया जाता है तो C# सक्षम बटन

private void dataGridView2_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
    bool flag = true;
    var senderGrid = (DataGridView)sender;
    senderGrid.EndEdit();

    for (int i = 0; i <= dataGridView2.Rows.Count - 1; i++)
    {
        if (e.RowIndex >= 0)
        {
            var cbxCell = (DataGridViewCheckBoxCell)senderGrid.Rows[i].Cells[1];

            if (!(bool)cbxCell.Value)
            {
                flag = false;
            }
        }
    }

    btn1.Enabled = flag;
}

private void dgvSelectedServices_CellContentClick(object sender, DataGridViewCellEventArgs e)
{


    bool flag = true;
    var senderGrid = (DataGridView)sender;
    senderGrid.EndEdit();

    for (int i = 0; i <= dgvSelectedServices.Rows.Count - 1; i++)
    {
        foreach (DataGridViewRow row in dgvSelectedServices.Rows)
        {

            if (e.RowIndex >= 0)
            {
                bool isselect = Convert.ToBoolean(row.Cells[2].Value);
                if (isselect)
                {
                    if (dgvSelectedServices.SelectedRows.Count == dgvSelectedServices.Rows.Count)
                    {
                        flag = true;
                    }

                }
                else
                {
                    flag = false;
                }
                btnNextToWIP.Enabled = flag;
            }

        }

    }


}