public override void updateDisplayedOpacity(OpacityTransform parentOpacity)
{
if (parentOpacity.tint != 255 || parentOpacity.add != 0)
{
this.cascadeOpacityEnabled = true;
}
base.updateDisplayedOpacity(parentOpacity);
}
protected override void TransformCore(Image image)
{
string waterMarkImagePath = HttpContext.Current.Server.MapPath(@"~\imgs\confidential.png");
using (Image waterMarkImage = Bitmap.FromFile(waterMarkImagePath))
using (Graphics graphics = Graphics.FromImage(image)) {
ImageAttributes attributes = new ImageAttributes();
attributes.SetColorMatrix(OpacityTransform.CreateOpacityMatrix(Opacity));
graphics.ApplyGraphicsQualitySetting(GraphicsQuality.High);
graphics.DrawImage(waterMarkImage, new Rectangle(0, 0, image.Width, image.Height), 0, 0, waterMarkImage.Width, waterMarkImage.Height, GraphicsUnit.Pixel, attributes);
graphics.Save();
}
}
