Question

EvoPDF HTML到PDF转换库（http://www.evopdf.com/）声称它支持Windows Azure云平台，但我无法让它工作。我得到了例外：

[Exception: Could not get conversion result header. Data receive error. Could not receive data. Error code: 109]
   EvoPdf.HtmlToPdf.ImgConverter.GetLayoutFromUrl(String url, ps& htmlParseInfo) +622
   EvoPdf.HtmlToPdf.PdfConverter.ConvertAndGetPdfDocument(String url, String htmlString, String baseUrl, String internalLinksDocUrl, Boolean fromUrl) +9748
   EvoPdf.HtmlToPdf.PdfConverter.ConvertAndSaveToStream(Stream outStream, String url, String htmlString, String baseUrl, String internalLinksDocUrl, Boolean fromUrl) +61
   EvoPdf.HtmlToPdf.PdfConverter.SavePdfFromUrlToStream(String url, Stream outPdfStream) +20

这看起来像是在图书馆通过网络请求获取HTML内容时失败了。 Azure中是否存在阻止传出Web请求的任何内容？

该库被部署为两个DLL，一个本机DLL和一个托管程序集 - 是否需要任何特殊的Azure配置才能加载本机DLL？（该库确实支持xcopy部署，我在其他托管环境中以这种方式工作）。

Answer 1

从我可以看到您需要使用Azure Web角色而不是Azure Web站点。这些网站不支持以完全信任方式运行。

http://blogs.msdn.com/b/silverlining/archive/2012/06/27/windows-azure-websites-web-roles-and-vms-when-to-use-which.aspx

EvoPdf有一个Azure示例项目，您可以下载该项目，演示如何使用可以运行EvoPdf dll的站点设置Web角色。

Answer 2

如果问题与您的原生DLL相关，您可能需要尝试更改ServiceDefinition.csdef中的以下属性：

enableNativeCodeExecution ：确保将其设置为true（默认值为true）
executionContext ：尝试将此更改为提升

您是否部署了64位版本的DLL？

我也在错误信息中看到“错误代码：109 ”，你能不能联系EvoPDF询问这意味着什么？

更新：如果您在ASP.NET中运行，是否可以尝试更改信任级别？

<configuration>
  <system.web>
    <trust level="Full" />
  </system.web>
</configuration>

Answer 3

适用于.NET的EVO HTML to PDF通用库可直接在Azure Web角色，Azure辅助角色和Azure虚拟机中使用。

对于Azure网站，您可以使用EVO HTML to PDF for Azure Websites solution。从那里复制的代码示例是：

protected void convertToPdfButton_Click(object sender, EventArgs e)
{
    // Get the server IP and port
    String serverIP = textBoxServerIP.Text;
    uint serverPort = uint.Parse(textBoxServerPort.Text);

    // Create a HTML to PDF converter object with default settings
    HtmlToPdfConverter htmlToPdfConverter = new HtmlToPdfConverter(serverIP, serverPort);

    // Set optional service password
    if (textBoxServicePassword.Text.Length > 0)
        htmlToPdfConverter.ServicePassword = textBoxServicePassword.Text;

    // Set HTML Viewer width in pixels which is the equivalent in converter of the browser window width
    htmlToPdfConverter.HtmlViewerWidth = int.Parse(htmlViewerWidthTextBox.Text);

    // Set HTML viewer height in pixels to convert the top part of a HTML page 
    // Leave it not set to convert the entire HTML
    if (htmlViewerHeightTextBox.Text.Length > 0)
        htmlToPdfConverter.HtmlViewerHeight = int.Parse(htmlViewerHeightTextBox.Text);

    // Set PDF page size which can be a predefined size like A4 or a custom size in points 
    // Leave it not set to have a default A4 PDF page
    htmlToPdfConverter.PdfDocumentOptions.PdfPageSize = SelectedPdfPageSize();

    // Set PDF page orientation to Portrait or Landscape
    // Leave it not set to have a default Portrait orientation for PDF page
    htmlToPdfConverter.PdfDocumentOptions.PdfPageOrientation = SelectedPdfPageOrientation();

    // Set the maximum time in seconds to wait for HTML page to be loaded 
    // Leave it not set for a default 60 seconds maximum wait time
    htmlToPdfConverter.NavigationTimeout = int.Parse(navigationTimeoutTextBox.Text);

    // Set an adddional delay in seconds to wait for JavaScript or AJAX calls after page load completed
    // Set this property to 0 if you don't need to wait for such asynchcronous operations to finish
    if (conversionDelayTextBox.Text.Length > 0)
        htmlToPdfConverter.ConversionDelay = int.Parse(conversionDelayTextBox.Text);

    // The buffer to receive the generated PDF document
    byte[] outPdfBuffer = null;

    if (convertUrlRadioButton.Checked)
    {
        string url = urlTextBox.Text;

        // Convert the HTML page given by an URL to a PDF document in a memory buffer
        outPdfBuffer = htmlToPdfConverter.ConvertUrl(url);
    }
    else
    {
        string htmlString = htmlStringTextBox.Text;
        string baseUrl = baseUrlTextBox.Text;

        // Convert a HTML string with a base URL to a PDF document in a memory buffer
        outPdfBuffer = htmlToPdfConverter.ConvertHtml(htmlString, baseUrl);
    }

    // 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("{0}; filename=Getting_Started.pdf; size={1}",
        openInlineCheckBox.Checked ? "inline" : "attachment", 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();
}

EvoPDF库在Windows Azure托管站点上失败

3 个答案: