Using UserControl to show bitmap flicker, I have used double buffer

Question

Hi!
I have created a coustom control derived from a UserControl using C#, and I created a bitmap to draw every component, and then draw this bitmap to the screen. But, when I pan this picture, it refresh from top to bottom in the control, and cause a flicker,
you can see many horizontal lines flicker in it.
So, what can I do to fix this problem?
Thank you very much!

Answer 1

some dode like this:
        protected override void OnPaint(PaintEventArgs e)
            CreateImage();
            if (imgImageForDraw != null)
                e.Graphics.DrawImage(imgImageForDraw, 0, 0, this.Width, this.Height);
           imgImageForDraw.Dispose();
        private void CreateImage()
            Graphics g;
            Pen p;
            //-------------------------------------------no image---------------------------------------
            #region no image
            if (imgImageToShow == null)//no image
                imgImageForDraw = new Bitmap(this.Width, this.Height);
                g = Graphics.FromImage(imgImageForDraw);
                g.Clear(Color.Black);
                p.Dispose();
            #endregion
            //-------------------------------------------have image---------------------------------------
            #region have image
            else//have image
                imgImageForDraw = new Bitmap(this.Width, this.Height);
                g = Graphics.FromImage(imgImageForDraw);
                if (bEnvironmentSetted)//simulate
                    log.info("Environment set", "SA" + nSAID.ToString() + ".SC" + nSCID.ToString() + ".CreateImage");
                    //-------------------------Pan Image------------------------------------------------
                    #region Pan Image
                    if (eMouseOperationStatus == MouseOperationStatus.PanImage)
                    {//simulate pan image
                        try
                            log.info("Pan Image", "SA" + nSAID.ToString() + ".SC" +
nSCID.ToString() + ".CreateImage");
                            Rectangle ShowPosition = new Rectangle(narrGeneralVariable[0],
narrGeneralVariable[1],
narrGeneralVariable[2],
narrGeneralVariable[3]);
                            Rectangle ShowPart = new Rectangle(narrGeneralVariable[4],
narrGeneralVariable[5],
narrGeneralVariable[6],
narrGeneralVariable[7]);
                            g.Clear(Color.Black);
                            g.DrawImage(imgImageToShow, ShowPosition, ShowPart, GraphicsUnit.Pixel);
                        catch (System.Exception PanEX)
                            ExceptionLog.info(PanEX.Message, "An exception break in Pan of Paint");
                    }//simulate pan image
                    #endregion
                }//simulate
            }//have image
            #endregion
            if (g != null) g.Dispose();
            log.info("End", "SA" + nSAID.ToString() + ".SC" + nSCID.ToString() + ".CreateImage");