Add Text to PDF in C#

readme.md

Read the complete article on adding text to the PDF documents using C#: https://blog.aspose.com/2021/08/26/add-text-to-a-pdf-using-csharp/

add-text-to-pdf-2.cs

// For complete examples and data files, please go to https://github.com/aspose-pdf/Aspose.PDF-for-.NET
string fontFile = "font.ttf";

// Load input PDF file
Document doc = new Document("input.pdf");

// Create text builder object for first page of document
TextBuilder textBuilder = new TextBuilder(doc.Pages[1]);

// Create text fragment with sample string
TextFragment textFragment = new TextFragment("Hello world");

if (fontFile != "")
{
    // Load the TrueType font into stream object
    using (FileStream fontStream = File.OpenRead(fontFile))
    {
        // Set the font name for text string
        textFragment.TextState.Font = FontRepository.OpenFont(fontStream, FontTypes.TTF);
        
        // Specify the position for Text Fragment
        textFragment.Position = new Position(10, 10);
        
        // Add the text to TextBuilder so that it can be placed over the PDF file
        textBuilder.AppendText(textFragment);
    }

    // Save resulting PDF document
    doc.Save("output.pdf");
}

add-text-to-pdf.cs

// For complete examples and data files, please go to https://github.com/aspose-pdf/Aspose.PDF-for-.NET
// Open document
Document pdfDocument = new Document("input.pdf");

// Get particular page
Page pdfPage = (Page)pdfDocument.Pages[1];

// Create text fragment
TextFragment textFragment = new TextFragment("main text");
textFragment.Position = new Position(100, 600);

// Set text properties
textFragment.TextState.FontSize = 12;
textFragment.TextState.Font = FontRepository.FindFont("TimesNewRoman");
textFragment.TextState.BackgroundColor = Aspose.Pdf.Color.FromRgb(System.Drawing.Color.LightGray);
textFragment.TextState.ForegroundColor = Aspose.Pdf.Color.FromRgb(System.Drawing.Color.Red);

// Create TextBuilder object
TextBuilder textBuilder = new TextBuilder(pdfPage);

// Append the text fragment to the PDF page
textBuilder.AppendText(textFragment);

// Save resulting PDF document.
pdfDocument.Save("output.pdf");

add-transparent-text-in-pdf.cs

// For complete examples and data files, please go to https://github.com/aspose-pdf/Aspose.PDF-for-.NET
// Create Document instance
Document doc = new Document("input.pdf");

// Create page to pages collection of PDF file
Aspose.Pdf.Page page = doc.Pages.Add();

// Create Graph object
Aspose.Pdf.Drawing.Graph canvas = new Aspose.Pdf.Drawing.Graph(100, 400);

// Create rectangle instance with certain dimensions
Aspose.Pdf.Drawing.Rectangle rect = new Aspose.Pdf.Drawing.Rectangle(100, 100, 400, 400);

// Create color object from Alpha color channel
rect.GraphInfo.FillColor = Aspose.Pdf.Color.FromRgb(System.Drawing.Color.FromArgb(128, System.Drawing.Color.FromArgb(12957183)));

// Add rectanlge to shapes collection of Graph object
canvas.Shapes.Add(rect);

// Add graph object to paragraphs collection of page object
page.Paragraphs.Add(canvas);

// Set value to not change position for graph object
canvas.IsChangePosition = false;

// Create TextFragment instance with sample value
TextFragment text = new TextFragment("transparent text transparent text transparent text transparent text transparent text transparent text transparent text transparent text transparent text transparent text transparent text transparent text transparent text transparent text transparent text transparent text ");

// Create color object from Alpha channel
Aspose.Pdf.Color color = Aspose.Pdf.Color.FromArgb(30, 0, 255, 0);

// Set color information for text instance
text.TextState.ForegroundColor = color;

// Add text to paragraphs collection of page instance
page.Paragraphs.Add(text);

// Save the updated PDF file
doc.Save("output.pdf");