我有这个dataGridView，我想转换成PDF文件。我怎么做？我在网上搜索，找到了一些代码，但似乎我找到的网站错过了很多东西。

using System.IO;
using System.Data;
using System.Reflection;
using iTextSharp.text.pdf;
using iTextSharp.text;

private void btnExportPdf_Click(object sender, EventArgs e)
{
    //Creating iTextSharp Table from the DataTable data
    PdfPTable pdfTable = new PdfPTable(dataGridView1.ColumnCount);
    pdfTable.DefaultCell.Padding = 3;
    pdfTable.WidthPercentage = 30;
    pdfTable.HorizontalAlignment = Element.ALIGN_LEFT;
    pdfTable.DefaultCell.BorderWidth = 1;

    //Adding Header row
    foreach (DataGridViewColumn column in dataGridView1.Columns)
    {
        PdfPCell cell = new PdfPCell(new Phrase(column.HeaderText));
        cell.BackgroundColor = new iTextSharp.text.Color(240, 240, 240);
        pdfTable.AddCell(cell);
    }

    //Adding DataRow
    foreach (DataGridViewRow row in dataGridView1.Rows)
    {
        foreach (DataGridViewCell cell in row.Cells)
        {
            pdfTable.AddCell(cell.Value.ToString());
        }
    }

    //Exporting to PDF
    string folderPath = "C:\\PDFs\\";
    if (!Directory.Exists(folderPath))
    {
        Directory.CreateDirectory(folderPath);
    }
    using (FileStream stream = new FileStream(folderPath + "DataGridViewExport.pdf", FileMode.Create))
    {
        Document pdfDoc = new Document(PageSize.A2, 10f, 10f, 10f, 0f);
        PdfWriter.GetInstance(pdfDoc, stream);
        pdfDoc.Open();
        pdfDoc.Add(pdfTable);
        pdfDoc.Close();
        stream.Close();
    }
}