/// <summary>
/// Watermarks a PDF file.
/// </summary>
/// <paramref name="fileName"/>
private void WatermarkPdf(string fileName)
{
var watermarkText = _operation.WatermarkText;
var sourceFile = $"{_operation.SourcePath}\\{fileName}";
var destinationPath = $"{_operation.DestinationPath}\\{PathWatermarked}";
var destinationFile = $"{destinationPath}\\{fileName}";
ValidatePath(destinationPath);
const float watermarkTrimmingRectangleWidth = 600;
const float watermarkTrimmingRectangleHeight = 600;
const float formWidth = 300;
const float formHeight = 300;
const float formXOffset = 0;
const float formYOffset = 0;
const float xTranslation = 50;
const float yTranslation = 25;
const double rotationInRads = Math.PI / 3;
try
{
FontCache.ClearSavedFonts();
}
catch (Exception exception)
{
Log.Error(exception.Message);
}
var font = PdfFontFactory.CreateFont(StandardFonts.COURIER);
const float fontSize = 119;
using var reader = new PdfReader(new MemoryStream(File.ReadAllBytes(sourceFile)));
using var pdfDoc = new PdfDocument(reader, new PdfWriter(destinationFile));
var numberOfPages = pdfDoc.GetNumberOfPages();
PdfPage page = null;
for (var i = 1; i <= numberOfPages; i++)
{
page = pdfDoc.GetPage(i);
var ps = page.GetPageSize();
//Center the annotation
var bottomLeftX = ps.GetWidth() / 2 - watermarkTrimmingRectangleWidth / 2;
var bottomLeftY = ps.GetHeight() / 2 - watermarkTrimmingRectangleHeight / 2;
var watermarkTrimmingRectangle = new Rectangle(bottomLeftX, bottomLeftY,
watermarkTrimmingRectangleWidth, watermarkTrimmingRectangleHeight);
var watermark = new PdfWatermarkAnnotation(watermarkTrimmingRectangle);
//Apply linear algebra rotation math
//Create identity matrix
var transform = new AffineTransform(); //No-args constructor creates the identity transform
//Apply translation
transform.Translate(xTranslation, yTranslation);
//Apply rotation
transform.Rotate(rotationInRads);
var fixedPrint = new PdfFixedPrint();
watermark.SetFixedPrint(fixedPrint);
//Create appearance
var formRectangle = new Rectangle(formXOffset, formYOffset, formWidth, formHeight);
//Observation: font XObject will be resized to fit inside the watermark rectangle
var form = new PdfFormXObject(formRectangle);
var gs1 = new PdfExtGState().SetFillOpacity(0.6f);
var canvas = new PdfCanvas(form, pdfDoc);
var transformValues = new float[6];
transform.GetMatrix(transformValues);
canvas.SaveState()
.BeginText().SetColor(ColorConstants.GRAY, true).SetExtGState(gs1)
.SetTextMatrix(transformValues[0], transformValues[1], transformValues[2], transformValues[3],
transformValues[4], transformValues[5])
.SetFontAndSize(font, fontSize)
.ShowText(watermarkText)
.EndText()
.RestoreState();
canvas.Release();
watermark.SetAppearance(PdfName.N, new PdfAnnotationAppearance(form.GetPdfObject()));
watermark.SetFlags(PdfAnnotation.PRINT);
page.AddAnnotation(watermark);
}
page?.Flush();
pdfDoc.Close();
}
public bool AddWaterMarkerToPdf(string pdfFile, string destFile, string text, string fontFamily, string fontColor, int fontSize = 50)
{
if (File.Exists(pdfFile))
{
try
{
using (var pr = new PdfReader(pdfFile))
{
var rgbColor = System.Drawing.ColorTranslator.FromHtml(fontColor);
PdfFont font = fontFamily.Contains("STSong") ? PdfFontFactory.CreateFont(fontFamily, "UniGB-UCS2-H", true)
: PdfFontFactory.CreateFont(fontFamily);//PdfFontFactory.CreateFont(fontFamily, "UniGB-UCS2-H", true);
if (font != null)
{
var textLength = font.GetWidth(text, fontSize);
var pw = new PdfWriter(destFile);
var pdfDoc = new PdfDocument(pr, pw);
Rectangle ps;
PdfCanvas canvas;
var pageCount = pdfDoc.GetNumberOfPages();
for (var i = 1; i < pageCount + 1; i++)
{
var page = pdfDoc.GetPage(i);
ps = page.GetPageSize();
float watermarkTrimmingRectangleWidth = textLength; //Math.Min(ps.GetWidth(), ps.GetHeight());
float watermarkTrimmingRectangleHeight = watermarkTrimmingRectangleWidth;
var rotationInRads = MathF.Atan2(ps.GetHeight(), ps.GetWidth());
//var angle = rotationInRads * 180f / MathF.PI;
float formWidth = ps.GetWidth(); //watermarkTrimmingRectangleWidth;
float formHeight = ps.GetHeight(); //watermarkTrimmingRectangleWidth;
float formXOffset = 0;
float formYOffset = 0;
float xTranslation = (formWidth - watermarkTrimmingRectangleWidth * MathF.Cos(rotationInRads)) / 2;
float yTranslation = (formHeight - watermarkTrimmingRectangleWidth * MathF.Sin(rotationInRads)) / 2;
//Center the annotation
Rectangle watermarkTrimmingRectangle = new Rectangle(0, 0, formWidth, formHeight);//watermarkTrimmingRectangleWidth, watermarkTrimmingRectangleWidth);
PdfWatermarkAnnotation watermark = new PdfWatermarkAnnotation(watermarkTrimmingRectangle);
//Apply linear algebra rotation math
//Create identity matrix
AffineTransform transform = new AffineTransform(); //No-args constructor creates the identity transform
//Apply translation
//transform.Translate(xTranslation, yTranslation);
//Apply rotation
transform.Translate(xTranslation, yTranslation);
transform.Rotate(rotationInRads);
PdfFixedPrint fixedPrint = new PdfFixedPrint();
watermark.SetFixedPrint(fixedPrint);
//Create appearance
Rectangle formRectangle = new Rectangle(formXOffset, formYOffset, formWidth, formHeight);
//Observation: font XObject will be resized to fit inside the watermark rectangle
PdfFormXObject form = new PdfFormXObject(formRectangle);
PdfExtGState gs1 = new PdfExtGState().SetFillOpacity(rgbColor.A / 255f);
canvas = new PdfCanvas(form, pdfDoc);
float[] transformValues = new float[6];
transform.GetMatrix(transformValues);
canvas.SaveState()
.BeginText().SetFillColorRgb(rgbColor.R / 225f, rgbColor.G / 225f, rgbColor.B / 255f).SetExtGState(gs1)
.SetTextMatrix(transformValues[0], transformValues[1], transformValues[2], transformValues[3], transformValues[4], transformValues[5])
.SetFontAndSize(font, fontSize)
.ShowText(text)
.EndText()
.RestoreState();
canvas.Release();
watermark.SetAppearance(PdfName.N, new PdfAnnotationAppearance(form.GetPdfObject()));
watermark.SetFlags(PdfAnnotation.PRINT);
page.AddAnnotation(watermark);
}
pdfDoc.Close();
}
else
{
App.Current.Dispatcher.Invoke(() =>
{
MessageBoxX.Show($"没有找到字体{fontFamily}，请确认已安装", "字体错误");
});
return(false);
}
return(true);
}
}
catch (Exception ex)
{
Analytics.TrackEvent("PDFError", new Dictionary <string, string>
{
["message"] = ex.ToString()
});
}
finally
{
File.Delete(pdfFile);
}
}
return(false);
}
public void SetFixed()
{
PdfFixedPrint fixedPrint = new PdfFixedPrint();
_watermark.SetFixedPrint(fixedPrint);
}
