How to Write .PDF file In C#.net

PDfSharp or ITextSharp would do the trick.

on PdfSharp is like this:

class Program
  {
    static void Main(string[] args)
    {
   // Create a new PDF document
      PdfDocument document = new PdfDocument();
      document.Info.Title = "Created with PDFsharp";
 
      // Create an empty page
      PdfPage page = document.AddPage();
 
      // Get an XGraphics object for drawing
      XGraphics gfx = XGraphics.FromPdfPage(page);
 
      // Create a font
      XFont font = new XFont("Verdana", 20, XFontStyle.BoldItalic);
 
      // Draw the text
      gfx.DrawString("Hello, World!", font, XBrushes.Black,
        new XRect(0, 0, page.Width, page.Height),
        XStringFormats.Center);
 
      // Save the document...
      const string filename = "HelloWorld.pdf";
      document.Save(filename);
      // ...and start a viewer.
      Process.Start(filename);
    }
  } 

on ITextSharp is like this:

iTextSharp.text.Document oDoc = new iTextSharp.text.Document();
PdfWriter.GetInstance(oDoc, new FileStream("HelloWorld.pdf", FileMode.Create));
oDoc.Open();
oDoc.Add(new Paragraph("Hello World!"));
oDoc.Close();

I have used them both, and must say both are great, but iTextSharp can also render a PDF to an image (rasterize). PdfSharp is faster and smaller also.

hope it helps.