Split PDF Documents

protected void splitPdfButton_Click(object sender, EventArgs e)
{
    Document pdfDocumentToSplit = null;
    Document splitResultDocument1 = null;
    Document splitResultDocument2 = null;
    try
    {
        // Load the PDF document to split
        // The document must remain opened until the PDF documents resulted after split are saved
        string pdfFileToSplitPath = Server.MapPath("~/DemoAppFiles/Input/PDF_Files/PDF_Document.pdf");
        pdfDocumentToSplit = new Document(pdfFileToSplitPath);

        // Get the page count of the document to split
        int pageCount = pdfDocumentToSplit.Pages.Count;

        // Check if the document has the minimum required number of page
        if (pageCount < 2)
        {
            return;
        }

        // Create the first PDF document resulted after split
        splitResultDocument1 = new Document();
        // Set license key received after purchase
        splitResultDocument1.LicenseKey = "4W9+bn19bn5ue2B+bn1/YH98YHd3d3c=";
        // Copy pages from loaded document into split result document
        splitResultDocument1.AppendDocument(pdfDocumentToSplit, 0, pageCount / 2);
        // Save the first PDF document document resulted after split in a memory buffer
        byte[] outPdfBuffer1 = splitResultDocument1.Save();

        // Create the second PDF document resulted after split  
        splitResultDocument2 = new Document();
        // Set license key received after purchase
        splitResultDocument2.LicenseKey = "4W9+bn19bn5ue2B+bn1/YH98YHd3d3c=";
        // Copy pages from loaded document into split result document
        splitResultDocument2.AppendDocument(pdfDocumentToSplit, pageCount / 2, pageCount - pageCount / 2);
        // Save the second PDF document document resulted after split in a memory buffer
        byte[] outPdfBuffer2 = splitResultDocument2.Save();

        // Send the PDF as response to browser

        // Set response content type
        Response.AddHeader("Content-Type", "application/pdf");

        // Instruct the browser to open the PDF file as an attachment or inline
        Response.AddHeader("Content-Disposition", String.Format("attachment; filename=Split_PDF_1.pdf.pdf; size={0}", outPdfBuffer1.Length.ToString()));

        // Write the PDF document buffer to HTTP response
        Response.BinaryWrite(outPdfBuffer1);

        // End the HTTP response and stop the current page processing
        Response.End();
    }
    finally
    {
        // Close all the PDF documents after the PDF documents resulted after split were already saved

        // Close the first split result document
        if (splitResultDocument1 != null)
            splitResultDocument1.Close();

        // Close the second split result document
        if (splitResultDocument2 != null)
            splitResultDocument2.Close();

        // Close the document to split
        if (pdfDocumentToSplit != null)
            pdfDocumentToSplit.Close();
    }
}

Protected Sub splitPdfButton_Click(ByVal sender As Object, ByVal e As EventArgs)
    Dim pdfDocumentToSplit As Document = Nothing
    Dim splitResultDocument1 As Document = Nothing
    Dim splitResultDocument2 As Document = Nothing
    Try
        ' Load the PDF document to split
        ' The document must remain opened until the PDF documents resulted after split are saved
        Dim pdfFileToSplitPath As String = Server.MapPath("~/DemoAppFiles/Input/PDF_Files/PDF_Document.pdf")
        pdfDocumentToSplit = New Document(pdfFileToSplitPath)

        ' Get the page count of the document to split
        Dim pageCount As Integer = pdfDocumentToSplit.Pages.Count

        ' Check if the document has the minimum required number of page
        If pageCount < 2 Then
            Return
        End If

        ' Create the first PDF document resulted after split
        splitResultDocument1 = New Document()
        ' Set license key received after purchase
        splitResultDocument1.LicenseKey = "4W9+bn19bn5ue2B+bn1/YH98YHd3d3c="
        ' Copy pages from loaded document into split result document
        splitResultDocument1.AppendDocument(pdfDocumentToSplit, 0, pageCount \ 2)
        ' Save the first PDF document document resulted after split in a memory buffer
        Dim outPdfBuffer1() As Byte = splitResultDocument1.Save()

        ' Create the second PDF document resulted after split  
        splitResultDocument2 = New Document()
        ' Set license key received after purchase
        splitResultDocument2.LicenseKey = "4W9+bn19bn5ue2B+bn1/YH98YHd3d3c="
        ' Copy pages from loaded document into split result document
        splitResultDocument2.AppendDocument(pdfDocumentToSplit, pageCount \ 2, pageCount - pageCount \ 2)
        ' Save the second PDF document document resulted after split in a memory buffer
        Dim outPdfBuffer2() As Byte = splitResultDocument2.Save()

        ' Send the PDF as response to browser

        ' Set response content type
        Response.AddHeader("Content-Type", "application/pdf")

        ' Instruct the browser to open the PDF file as an attachment or inline
        Response.AddHeader("Content-Disposition", String.Format("attachment; filename=Split_PDF_1.pdf.pdf; size={0}", outPdfBuffer1.Length.ToString()))

        ' Write the PDF document buffer to HTTP response
        Response.BinaryWrite(outPdfBuffer1)

        ' End the HTTP response and stop the current page processing
        Response.End()
    Finally
        ' Close all the PDF documents after the PDF documents resulted after split were already saved

        ' Close the first split result document
        If splitResultDocument1 IsNot Nothing Then
            splitResultDocument1.Close()
        End If

        ' Close the second split result document
        If splitResultDocument2 IsNot Nothing Then
            splitResultDocument2.Close()
        End If

        ' Close the document to split
        If pdfDocumentToSplit IsNot Nothing Then
            pdfDocumentToSplit.Close()
        End If
    End Try
End Sub