private void addVisibleSignature(PdfSignatureAppearance signAppearance, PdfStamper stamper)
{
if (SignatureData.VisibleSignature == null) return;
signAppearance.Image = string.IsNullOrEmpty(SignatureData.VisibleSignature.ImagePath) ? null : Image.GetInstance(SignatureData.VisibleSignature.ImagePath);
signAppearance.Layer2Text = SignatureData.VisibleSignature.CustomText;
if (SignatureData.VisibleSignature.RunDirection == null)
SignatureData.VisibleSignature.RunDirection = PdfRunDirection.LeftToRight;
signAppearance.RunDirection = (int)SignatureData.VisibleSignature.RunDirection;
signAppearance.Layer2Font = SignatureData.VisibleSignature.Font.Fonts[0];
var pageNumber = SignatureData.VisibleSignature.UseLastPageToShowSignature ? stamper.Reader.NumberOfPages : SignatureData.VisibleSignature.PageNumberToShowSignature;
signAppearance.SetVisibleSignature(SignatureData.VisibleSignature.Position, pageNumber, null);
}