private void Test()
    {
        string sourceFileName = @"C:\My_Files\Test.txt";
        //string sourceFileName = @"C:\My_Files\Test.doc";
        //string sourceFileName = @"C:\My_Files\Test.xlsx";

        StringBuilder FileTextBuilder = new StringBuilder();
        using (FileStream ReadStream = File.OpenRead(sourceFileName))
        {
            byte[] DataTransit = new byte[ReadStream.Length + 1];
            UTF8Encoding DataEncoding = new UTF8Encoding(true);
            while (ReadStream.Read(DataTransit, 0, DataTransit.Length) > 0)
            {
                FileTextBuilder.Append(DataEncoding.GetString(DataTransit));
            }
        }

        string sourceContent = FileTextBuilder.ToString();

        PdfDocument document = new PdfDocument();
        document.Info.Title = "Created with PDFsharp";

        PdfPage page = document.AddPage();
        XGraphics gfx = XGraphics.FromPdfPage(page);
        XFont font = new XFont("Verdana", 10, XFontStyle.Regular);

        gfx.DrawString(sourceContent, font, XBrushes.Black,
          new XRect(0, 0, page.Width, page.Height),
          XStringFormats.TopLeft);

        string destinationFileName = @"C:\My_Files\Test.pdf";
        document.Save(destinationFileName);
        document.Close();
    }

private void Test()
    {
        string sourceFileName = @"C:\My_Files\Test.txt";
        //string sourceFileName = @"C:\My_Files\Test.doc";
        //string sourceFileName = @"C:\My_Files\Test.xlsx";

        StringBuilder FileTextBuilder = new StringBuilder();
        string TBFormatted  = "";
    if(sourceFileName.Contains(".txt"){
        using (FileStream ReadStream = File.OpenRead(sourceFileName))
        {
            byte[] DataTransit = new byte[ReadStream.Length + 1];
            UTF8Encoding DataEncoding = new UTF8Encoding(true);
            while (ReadStream.Read(DataTransit, 0, DataTransit.Length) > 0)
            {
                FileTextBuilder.Append(DataEncoding.GetString(DataTransit));
            }
            //read in your .txt file to a string and format it. Pdfsharp/MigraDoc like to use /r for new line characters, whereas other formatters use /n and sometimes /r/n, it will depend on the content
            TBFormatted = FormatTXT(TextBuilder.ToString());
        }
     }
     if(sourceFileName.Contains(".doc"){
                 //read in your .doc file to a string and format it
          TBFormatted = ExtractDOC(sourceFileName);
      }
      else if(sourceFileName.Contains(".xlsx"){
           //read in your .xlsx file to a string and format it. 
          TBFormatted = ExtractXLSX(sourceFileName);
      }

        string sourceContent = TBFormatted;
        PdfDocument document = new PdfDocument();
        document.Info.Title = "Created with PDFsharp";

        PdfPage page = document.AddPage();
        XGraphics gfx = XGraphics.FromPdfPage(page);
        XFont font = new XFont("Verdana", 10, XFontStyle.Regular);

        gfx.DrawString(sourceContent, font, XBrushes.Black,
          new XRect(0, 0, page.Width, page.Height),
          XStringFormats.TopLeft);

        string destinationFileName = @"C:\My_Files\Test.pdf";
        document.Save(destinationFileName);
        document.Close();
    }
private string FormatTXT(string input){
    return something;
}
private string ExtractDOC(string input){
    return something;
}
private string ExtractXLSX(string input){
    return something;
}

public static string LoadFile(string filePath)
        {
            TextReader tr = new StreamReader(filePath);
            string _fileString = tr.ReadToEnd();
            tr.Close();
            tr.Dispose();
            return _fileString;
        }