export arabic data to pdf using itext - pdf

Question

I want to export gridview data to PDF, using iTextsharp. The gridview data contains Persian/Arabic data. It results in just a blank PDF file... what could be the reason?
Following is my code:
GridView1.DataSource = Session("dt")
GridView1.AllowPaging = False
GridView1.DataBind()
Dim bf As BaseFont = BaseFont.CreateFont(Environment.GetEnvironmentVariable("windir") & "\fonts\tahoma.ttf", BaseFont.IDENTITY_H, True)
Dim font As New iTextSharp.text.Font(bf, 10, iTextSharp.text.Font.NORMAL)
Dim table As New iTextSharp.text.pdf.PdfPTable(GridView1.Columns.Count)
Dim widths As Integer() = New Integer(GridView1.Columns.Count - 1) {}
For x As Integer = 0 To GridView1.Columns.Count - 1
widths(x) = CInt(GridView1.Columns(x).ItemStyle.Width.Value)
Dim cellText As String = Server.HtmlDecode(GridView1.HeaderRow.Cells(x).Text)
Dim cell As New iTextSharp.text.pdf.PdfPCell(New Phrase(12, cellText, font))
cell.BackgroundColor = New BaseColor(GridView1.HeaderStyle.BackColor)
'cell.BackgroundColor = New BaseColor(System.Drawing.ColorTranslator.FromHtml("#008000"))
cell.RunDirection = PdfWriter.RUN_DIRECTION_RTL
table.AddCell(cell)
Next
table.SetWidths(widths)
For i As Integer = 0 To GridView1.Rows.Count - 1
If GridView1.Rows(i).RowType = DataControlRowType.DataRow Then
For j As Integer = 0 To GridView1.Columns.Count - 1
Dim cellText As String = Server.HtmlDecode(GridView1.Rows(i).Cells(j).Text)
Dim cell As New iTextSharp.text.pdf.PdfPCell(New Phrase(12, cellText, font))
'Set Color of Alternating row
If i Mod 2 <> 0 Then
'cell.BackgroundColor = New BaseColor(System.Drawing.ColorTranslator.FromHtml("#C2D69B"))
cell.BackgroundColor = New BaseColor(GridView1.RowStyle.BackColor)
End If
cell.RunDirection = PdfWriter.RUN_DIRECTION_RTL
table.AddCell(cell)
Next
End If
Next
'Create the PDF Document
Dim pdfDoc As New Document(PageSize.A4, 10.0F, 10.0F, 10.0F, 0.0F)
PdfWriter.GetInstance(pdfDoc, Response.OutputStream)
pdfDoc.Open()
pdfDoc.Add(table)
pdfDoc.Close()
Response.ContentType = "application/pdf"
Response.AddHeader("content-disposition", "attachment;filename=GridViewExport.pdf")
Response.Cache.SetCacheability(HttpCacheability.NoCache)
Response.Write(pdfDoc)
Response.[End]()

Answer 1

Your question is somewhat misleading because the problem you are experiencing is not caused by the fact that you are using Arabic. If you would write the document to a file, you would notice that the file is OK.
There is a serious error in these lines:
PdfWriter.GetInstance(pdfDoc, Response.OutputStream)
...
Response.ContentType = "application/pdf"
Response.AddHeader("content-disposition", "attachment;filename=GridViewExport.pdf")
Response.Cache.SetCacheability(HttpCacheability.NoCache)
Response.Write(pdfDoc)
Response.[End]()
First you use the Response.OutputStream to write PDF bytes to it, then you use the Response object to set content headers. This is illegal syntax: you should always define your headers before sending any bytes to the output stream.
Furtermore: you should write PDF bytes to the outputstream, not a Document object. The following line is complete non sense:
Response.Write(pdfDoc)
For an example on how to send content bytes to the Response.OutputStream, read the answers to the following question: iTextSharp generated PDF: How to send the pdf to the client and add a prompt?
If you don't know how to create content byte, take a look at this code snippet:
using (MemoryStream myMemoryStream = new MemoryStream()) {
Document document = new Document();
PdfWriter PDFWriter = PdfWriter.GetInstance(document, myMemoryStream);
document.Open();
...
document.Close();
byte[] content = myMemoryStream.ToArray();
...
}
Never write an object such as document to an output stream, always use a byte[].