How to create Watermarks using Foxit PDF SDK (.NET)

A watermark is a type of PDF annotation and is widely used in PDF documents. A watermark is a visible embedded overlay on a document consisting of text, a logo, or a copyright notice. The purpose of a watermark is to brand your work and discourage its unauthorized use. Foxit PDF SDK provides APIs to work with watermarks, allowing applications to create, insert, release and remove watermarks.

Example:

How to create a text watermark and insert it into the first page

using foxit.common;
using foxit.pdf;
...
// Assuming PDFDoc doc has been loaded.
WatermarkSettings settings = new WatermarkSettings();
settings.offset_x = 0;
settings.offset_y = 0;
settings.opacity = 90;
settings.position = Position.e_PosTopRight;
settings.rotation = -45.0f;
settings.scale_x = 1.0f;
settings.scale_y = 1.0f;
WatermarkTextProperties text_properties = new WatermarkTextProperties();
text_properties.alignment = Alignment.e_AlignmentCenter;
text_properties.color = 0xF68C21;
text_properties.font_style = WatermarkTextProperties.FontStyle.e_FontStyleNormal;
text_properties.line_space = 1;
text_properties.font_size = 12.0f;
text_properties.font = font;
Watermark watermark = new Watermark(doc, "Foxit PDF SDK\nwww.foxitsoftware.com", text_properties, settings);
watermark.InsertToPage(doc.GetPage(0));
// Save document to file
...

How to create an image watermark and insert it into the first page

using foxit.common;
using foxit.pdf;
...
// Assuming PDFDoc doc has been loaded.
// Assuming PDFPage page has been loaded and parsed.
WatermarkSettings settings = new WatermarkSettings();
settings.flags = (int)(WatermarkSettings.Flags.e_FlagASPageContents | WatermarkSettings.Flags.e_FlagOnTop);
settings.offset_x = 0.0f;
settings.offset_y = 0.0f;
settings.opacity = 20;
settings.position = Position.e_PosCenter;
settings.rotation = 0.0f;
Image image = new Image(image_file);
System.Drawing.Bitmap bitmap = image.GetFrameBitmap(0);
settings.scale_x = page.GetWidth() * 0.618f / bitmap.Width;
settings.scale_y = settings.scale_x;
Watermark watermark = new Watermark(doc, image, 0, settings);
watermark.InsertToPage(doc.GetPage(0));
// Save document to file.
...

How to remove all watermarks from a page

using foxit.common;
using foxit.pdf;
...
// Assuming PDFPage page has been loaded and parsed.
...
page.RemoveAllWatermarks();
...
// Save document to file
...