如何在C#中关闭MessageBox后强制按钮,TextBoxes在窗体上重绘

DialogResult result = MessageBox.Show("您确定要关闭此窗口吗？", "提示", MessageBoxButtons.OKCancel);

if (result == DialogResult.OK)
{
    this.Close();
    this.Refresh();
}

foreach (Control control in this.Controls)
{
    if (control is TextBox)
    {
        control.Invalidate();
    }
}

private void button1_Click(object sender, EventArgs e)
{
    DialogResult result = MessageBox.Show("您确定要关闭此窗口吗？", "提示", MessageBoxButtons.OKCancel);

    if (result == DialogResult.OK)
    {
        this.Close();
        this.Refresh();

        foreach (Control control in this.Controls)
        {
            if (control is TextBox)
            {
                control.Invalidate();
            }
        }
    }
}