C#form 将Label变成圆角矩形

private void label_Paint(object sender, PaintEventArgs e)
{
    DrawRoundRect(e.Graphics, label);//这里出现问题 e.graphics 不能用
}
private void DrawRoundRect(Graphics graphics, Label label)
{
    float X = float.Parse(label.Width.ToString()) - 1;
    float Y = float.Parse(label.Height.ToString()) - 1;
    PointF[] points = {
        new PointF(2,     0),
        new PointF(X-2,   0),
        new PointF(X-1,   1),
        new PointF(X,     2),
        new PointF(X,     Y-2),
        new PointF(X-1,   Y-1),
        new PointF(X-2,   Y),
        new PointF(2,     Y),
        new PointF(1,     Y-1),
        new PointF(0,     Y-2),
        new PointF(0,     2),
        new PointF(1,     1)
        };
    GraphicsPath path = new GraphicsPath();
    path.AddLines(points);//出错
    Pen pen = new Pen(Color.FromArgb(150, Color.Blue), 1);
    pen.DashStyle = DashStyle.Solid;
    graphics.DrawPath(pen, path);//报错
}