private void ShowPDF(string fileName)
{
PDFLibrary qp = new PDFLibrary();
qp.UnlockKey(LicenseKey);
qp.LoadFromFile(fileName);
// Fit width of PDF to width of picture box
int dpi = Convert.ToInt32((pictureBox1.Width * 72) / qp.PageWidth());
byte[] bmpData = (byte[])qp.RenderPageToVariant(dpi, 1, 0);
MemoryStream ms = new MemoryStream(bmpData);
Bitmap bmp = new Bitmap(ms);
pictureBox1.Image = bmp;
ms.Dispose();
}