如何在C#中级联式下拉列表的文本框中显示固定数据？

// 窗体加载事件
private void Form1_Load(object sender, EventArgs e)
{
    // 初始化父级下拉列表数据
    comboBoxParent.Items.AddRange(new string[] { "Option 1", "Option 2", "Option 3" });
}

// 父级下拉列表选中事件
private void comboBoxParent_SelectedIndexChanged(object sender, EventArgs e)
{
    // 根据选中的父级选项设置子级下拉列表的数据源
    string selectedParent = comboBoxParent.SelectedItem.ToString();
    comboBoxChild.Items.Clear();

    if (selectedParent == "Option 1")
    {
        comboBoxChild.Items.AddRange(new string[] { "Child 1-1", "Child 1-2", "Child 1-3" });
    }
    else if (selectedParent == "Option 2")
    {
        comboBoxChild.Items.AddRange(new string[] { "Child 2-1", "Child 2-2", "Child 2-3" });
    }
    else if (selectedParent == "Option 3")
    {
        comboBoxChild.Items.AddRange(new string[] { "Child 3-1", "Child 3-2", "Child 3-3" });
    }
}