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        private void frmMain_WheelUsage(object sender, MouseEventArgs e)
        {
            if (Properties.Settings.Default.useScrollWheel == true)
            {
                if (e.Delta > 0) picBack();
                else if (e.Delta < 0) picForward();
            }
            else if (opened == true)
            {
                if (zoomed == false)
                {
                    pbMain.Dock = DockStyle.None;
                    pbMain.SizeMode = PictureBoxSizeMode.StretchImage;
                }
                pbMain.Size = getDimension();
                zoomed = true;
                pbMain.SendToBack();
                if (e.Delta > 0)
                {
                    int tempX = pbMain.Size.Width + 30;
                    int tempY = pbMain.Size.Height + 30;
                    int posX = pbMain.Location.X - 15;
                    int posY = pbMain.Location.Y - 15;
                    pbMain.Size = new Size(tempX, tempY);
                    pbMain.Location = new Point(posX, posY);
                }
                else if (e.Delta < 0)
                {
                    int tempX = pbMain.Size.Width - 30;
                    int tempY = pbMain.Size.Height - 30;
                    int posX = pbMain.Location.X + 15;
                    int posY = pbMain.Location.Y + 15;
                    pbMain.Size = new Size(tempX, tempY);
                    pbMain.Location = new Point(posX, posY);
                }
            }
        }


        Size getDimension()
        {
            if (pbMain.Image.Size.Width > pbMain.Size.Width || pbMain.Image.Size.Height > pbMain.Size.Height)
            {
                double dimension = (double)pbMain.Image.Size.Width / (double)pbMain.Image.Size.Height;
                double temp1 = (double)pbMain.Image.Size.Width / (double)pbMain.Size.Width;
                double temp2 = (double)pbMain.Image.Size.Height / (double)pbMain.Size.Height;

                if (temp1 > temp2) //Breite
                {
                    double breite = dimension * (double)pbMain.Size.Height;
                    return new Size((int)breite, pbMain.Size.Height);
                }
                else //Höhe
                {
                    double hoehe = (double)pbMain.Size.Width / dimension;
                    return new Size(pbMain.Size.Width, (int)hoehe);
                }
            }
            else
            {
                return new Size(pbMain.Image.Size.Width, pbMain.Image.Size.Height);
            }
        }