将值从DataGriedView导出到PDF

Question

我是编程新手，我正在尝试将Windows窗体中的datagriedview的值导出为PDF。 但是，当我执行此代码时，它会在foreach上使我的执行崩溃，在这里我可以正确获得单元格值（PdfPCell pdfCell = new PdfPCell（new Phrase（cell.Value.ToString（）））;）有人可以帮助我使用此代码吗？ / p>

    private void button1_Click(object sender, EventArgs e)
    {
        PdfPTable pdfTable = new PdfPTable(dataGridView1.ColumnCount);
        pdfTable.DefaultCell.Padding = 3;
        pdfTable.WidthPercentage = 30;
        pdfTable.HorizontalAlignment = Element.ALIGN_LEFT;
        pdfTable.DefaultCell.BorderWidth = 1;

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


        foreach (DataGridViewRow row in dataGridView1.Rows)
        {
            foreach (DataGridViewCell cell in row.Cells)
            {
                PdfPCell pdfCell = new PdfPCell(new Phrase(cell.Value.ToString()));
                pdfTable.AddCell(pdfCell);
            }
        }


        string folderPath = "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();
        }


    }