C#中pictureBox上如何设置label透明

在pictureBox的Paint事件中写下如下代码
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
foreach (Control C in this.Controls)
{
if (C is Label)
{
Label L = (Label)C;
L.Visible = false;
e.Graphics.DrawString(L.Text, L.Font, new
SolidBrush(L.ForeColor), L.Left - pictureBox1.Left, L.Top - pictureBox1.Top);
}
}
}

或者在载入页面的时候在LOAD中写入下面代码：

pictureBox1.SendToBack();
label1.BackColor = Color.Transparent;
label1.Parent = pictureBox1;
label1.BringToFront();