whats missing im using itext sharp to export wpf grid to pdf

Question

PdfPTable table = new PdfPTable(dataGridCst.Columns.Count);

//Table header

BaseFont btnColumnHeader = BaseFont.CreateFont(BaseFont.TIMES_ROMAN, BaseFont.CP1252, BaseFont.NOT_EMBEDDED);

iTextSharp.text.Font fntColumnHeader = new iTextSharp.text.Font(btnColumnHeader, 10, 1, BaseColor.WHITE);

for (int i = 0; i < dataGridCst.Columns.Count; i++)

{

PdfPCell cell = new PdfPCell();

cell.BackgroundColor = BaseColor.GRAY;

cell.AddElement(new Chunk(dataGridCst.Columns[i], fntColumnHeader));// <<<< keeps showing a red line

table.AddCell(cell);

}

//table Data

for (int i = 0; i < dataGridCst.Items.Count; i++)

{

for (int j = 0; j < dataGridCst.Columns.Count; j++)

{

table.AddCell(dataGridCst.Items.ToString());

}

}