public partial class PanelEx : Panel

    {

        protected Graphics graphics;

        protected override CreateParams CreateParams

        {

            get

            {

                CreateParams cp = base.CreateParams;

                cp.ExStyle |= 0x00000020; // 实现透明样式

                return cp;

            }

        }

        public PanelEx()

        {

            InitializeComponent();

            this.BackColor = Color.Transparent;

            this.ForeColor = Color.Transparent;

        }

        protected override void OnPaintBackground(PaintEventArgs pevent)

        {

        }

        protected override void OnPaint(PaintEventArgs e)

        {

            base.OnPaint(e);

            this.graphics = e.Graphics;

            this.graphics.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAlias;

            this.graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBilinear;

            this.graphics.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;

            this.graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

            this.graphics.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;

            if (this.BackgroundImage != null)

            {

                int width = this.Width;

                int height = this.Height;

                Rectangle recModel = new Rectangle(, , width, height);

                this.graphics.DrawImage(this.BackgroundImage, recModel);

            }

            else if (this.ForeColor != Color.Transparent)

            {

                this.graphics.Clear(this.ForeColor);

            }

        }

    }