How to Export textbox values to pdf form...?

try
{
string textBoxText; // your Text Box text
System.IO.TextReader readFile = new StreamReader("Text.txt");
int yPoint = 0;

PdfDocument pdf = new PdfDocument();
pdf.Info.Title = "TXT to PDF";
PdfPage pdfPage = pdf.AddPage();
XGraphics graph = XGraphics.FromPdfPage(pdfPage);
XFont font = new XFont("Verdana", 20, XFontStyle.Regular );

while (true)
{
    if (string.IsNullOrEmpty("textBoxText"))
    {
        graph.DrawString(line, font, XBrushes.Black, new XRect(40, yPoint, pdfPage.Width.Point, pdfPage.Height.Point), XStringFormats.TopLeft);
        yPoint = yPoint + 40;
    }
}

string pdfFileName = "MyPdfFile.pdf";
pdf.Save(pdfFileName);
readFile.Close();
readFile = null; 
Process.Start(pdfFileName);
}
catch(Exception ex)
{
     //Log exception
}