使用EvoPdf的Document对象创建页码未显示的页脚

Question

我有一个由EvoPdf HtmlToPdfConverter从html转换而来的pdf文件。我通过evopdf文档类读取文件字节，并向其中添加页脚元素。保存字节后，它将显示内联webBrowser。没有显示带有页码的页脚。

这是我的密码：

Document pdfDoc = new Document("myFilePath.pdf");

//create the footer element
TextElement footerText = new TextElement(0, 30, "Page &p; of &P;  ",
        new System.Drawing.Font( new System.Drawing.FontFamily("Arial"), 10, System.Drawing.GraphicsUnit.Point));
footerText.EmbedSysFont = true;
footerText.TextAlign = HorizontalTextAlign.Right;
pdfDoc.AddFooterTemplate(50);
pdfDoc.Footer.AddElement(footerText);

byte[] outBuffer = pdfDoc.Save();
pdfDoc.Close();
//...

如果我将脚注元素添加到htmlToPdfConverter中，它将显示得很好。

我该怎么显示呢？

谢谢。

Answer 1

我也遇到过同样的情况。基本上，我想在不使用header转换器的情况下向现有的PDF添加页眉和页脚。

下面是对现有代码进行一些调整的解决方案：

//Create a blank document.
Document MergeDocument = new Document(); 
Document pdfDoc = new Document("myFilePath.pdf");

//Merged n number of existing PDFs to newly created document.
MergedDocument.AppendDocument(pdfDoc, true, true, true);

//create the footer element
TextElement footerText = new TextElement(0, 30, "Page &p; of &P;  ",
    new System.Drawing.Font( new System.Drawing.FontFamily("Arial"), 10, System.Drawing.GraphicsUnit.Point));
footerText.EmbedSysFont = true;
footerText.TextAlign = HorizontalTextAlign.Right;

//Apply footer to the newly created document after all documents appended.
MergeDocument.AddFooterTemplate(50);
MergeDocument.Footer.AddElement(footerText);

byte[] outBuffer = MergeDocument.Save();

MergeDocument.Close();

Answer 2

为了在现有的PDF文档上应用页眉和页脚，您必须创建一个空的文档对象，定义页眉和页脚，然后使用方法Document.AppendDocument( documents，bool enableHeaderAndFooter，bool drawHeaderOnFirstPage，bool drawFooterOnFirstPage)追加外部PDF文档。

下面你可以找到一个完整的例子。您还可以在在外部PDF中添加页眉和页脚上找到一个在线演示。

public void protected void createPdfButton_Click(object sender, EventArgs e)
{
    // Create a PDF document
    Document pdfDocument = new Document();

    // Add a PDF page to PDF document
    PdfPage pdfPage = pdfDocument.AddPage();

    try
    {
        // Add a default document header
        AddHeader(pdfDocument, true);

        // Add a default document footer
        AddFooter(pdfDocument, true, true);

        // Create a HTML to PDF element to add to document
        HtmlToPdfElement htmlToPdfElement = new HtmlToPdfElement(0, 0, urlTextBox.Text);

        // Optionally set a delay before conversion to allow asynchonous scripts to finish
        htmlToPdfElement.ConversionDelay = 2;

        // Add HTML to PDF element to document
        pdfPage.AddElement(htmlToPdfElement);

        // Automatically close the external PDF documents after the final document is saved
        pdfDocument.AutoCloseAppendedDocs = true;

        // Insert an external PDF document in the beginning of the final PDF document
        string pdfFileBefore = Server.MapPath("~/DemoAppFiles/Input/PDF_Files/Merge_Before_Conversion.pdf");
        Document startExternalDocument = new Document(pdfFileBefore);
        pdfDocument.InsertDocument(0, startExternalDocument, addHeaderFooterInInsertedPdfCheckBox.Checked,
                        showHeaderInFirstPageCheckBox.Checked, showFooterInFirstPageCheckBox.Checked);

        // Append an external PDF document at the end of the final PDF document
        string pdfFileAfter = Server.MapPath("~/DemoAppFiles/Input/PDF_Files/Merge_After_Conversion.pdf");
        Document endExternalDocument = new Document(pdfFileAfter);
        pdfDocument.AppendDocument(endExternalDocument, addHeaderFooterInAppendedPdfCheckBox.Checked, true, true);

        // Save the PDF document in a memory buffer
        byte[] outPdfBuffer = pdfDocument.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=Header_Footer_in_External_PDF.pdf; size={0}", outPdfBuffer.Length.ToString()));

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

        // End the HTTP response and stop the current page processing
        Response.End();
    }
    finally
    {
        // Close the PDF document
        pdfDocument.Close();
    }
}

/// <summary>
/// Add a header to document
/// </summary>
/// <param name="pdfDocument">The PDF document object</param>
/// <param name="drawHeaderLine">A flag indicating if a line should be drawn at the bottom of the header</param>
private void AddHeader(Document pdfDocument, bool drawHeaderLine)
{
    string headerHtmlUrl = Server.MapPath("~/DemoAppFiles/Input/HTML_Files/Header_HTML.html");

    // Create the document footer template
    pdfDocument.AddHeaderTemplate(60);

    // Create a HTML element to be added in header
    HtmlToPdfElement headerHtml = new HtmlToPdfElement(headerHtmlUrl);

    // Set the HTML element to fit the container height
    headerHtml.FitHeight = true;

    // Add HTML element to header
    pdfDocument.Header.AddElement(headerHtml);

    if (drawHeaderLine)
    {
        float headerWidth = pdfDocument.Header.Width;
        float headerHeight = pdfDocument.Header.Height;

        // Create a line element for the bottom of the header
        LineElement headerLine = new LineElement(0, headerHeight - 1, headerWidth, headerHeight - 1);

        // Set line color
        headerLine.ForeColor = Color.Gray;

        // Add line element to the bottom of the header
        pdfDocument.Header.AddElement(headerLine);
    }
}

/// <summary>
/// Add a footer to document
/// </summary>
/// <param name="pdfDocument">The PDF document object</param>
/// <param name="addPageNumbers">A flag indicating if the page numbering is present in footer</param>
/// <param name="drawFooterLine">A flag indicating if a line should be drawn at the top of the footer</param>
private void AddFooter(Document pdfDocument, bool addPageNumbers, bool drawFooterLine)
{
    string footerHtmlUrl = Server.MapPath("~/DemoAppFiles/Input/HTML_Files/Footer_HTML.html");

    // Create the document footer template
    pdfDocument.AddFooterTemplate(60);

    // Set footer background color
    RectangleElement backColorRectangle = new RectangleElement(0, 0, pdfDocument.Footer.Width, pdfDocument.Footer.Height);
    backColorRectangle.BackColor = Color.WhiteSmoke;
    pdfDocument.Footer.AddElement(backColorRectangle);

    // Create a HTML element to be added in footer
    HtmlToPdfElement footerHtml = new HtmlToPdfElement(footerHtmlUrl);

    // Set the HTML element to fit the container height
    footerHtml.FitHeight = true;

    // Add HTML element to footer
    pdfDocument.Footer.AddElement(footerHtml);

    // Add page numbering
    if (addPageNumbers)
    {
        // Create a text element with page numbering place holders &p; and & P;
        TextElement footerText = new TextElement(0, 30, "Page &p; of &P;  ",
            new System.Drawing.Font(new System.Drawing.FontFamily("Times New Roman"), 10, System.Drawing.GraphicsUnit.Point));

        // Align the text at the right of the footer
        footerText.TextAlign = HorizontalTextAlign.Right;

        // Set page numbering text color
        footerText.ForeColor = Color.Navy;

        // Embed the text element font in PDF
        footerText.EmbedSysFont = true;

        // Add the text element to footer
        pdfDocument.Footer.AddElement(footerText);
    }

    if (drawFooterLine)
    {
        float footerWidth = pdfDocument.Footer.Width;

        // Create a line element for the top of the footer
        LineElement footerLine = new LineElement(0, 0, footerWidth, 0);

        // Set line color
        footerLine.ForeColor = Color.Gray;

        // Add line element to the bottom of the footer
        pdfDocument.Footer.AddElement(footerLine);
    }
}