iTextSharp  实现pdf内容的读取   要怎么读取pdf的页数呢？

代码如下：

            Dim reader As New iTextSharp.text.pdf.PdfReader(fl)
            Dim n As Integer = reader.NumberOfPages
            Dim str As String = ""
            For i As Integer = 1 To n
                Dim strategy As object = New iTextSharp.text.pdf.parser.SimpleTextExtractionStrategy()
                Dim currentText As String = iTextSharp.text.pdf.parser.PdfTextExtractor.GetTextFromPage(Reader, i, strategy)
                currentText = Encoding.UTF8.GetString(ASCIIEncoding.Convert(Encoding.[Default], Encoding.UTF8, Encoding.[Default].GetBytes(currentText)))
                str &= currentText
               
            Next
            output.show(str)
           
            reader.Close()

谢谢！