如何在Visual Studio中展开DataGridView中的行？

private void dataGridView1_RowHeaderMouseClick(object sender, DataGridViewCellMouseEventArgs e)
{
    if (e.RowIndex >= 0 && e.Button == MouseButtons.Left)
    {
        DataGridViewRow row = dataGridView1.Rows[e.RowIndex];
        row.Cells[0].Value = "-";
        // 添加展开的子行数据
        // ...
    }
}

private void dataGridView1_RowHeaderMouseDoubleClick(object sender, DataGridViewCellMouseEventArgs e)
{
    if (e.RowIndex >= 0 && e.Button == MouseButtons.Left)
    {
        DataGridViewRow row = dataGridView1.Rows[e.RowIndex];
        row.Cells[0].Value = "+";
        // 移除子行数据，实现折叠
        // ...
    }
}