合并内存流以在 c# 中创建 http PDF 响应 [英] Merging Memory Streams to create a http PDF response in c#

问题描述

我正在尝试将 2 个水晶报告合并到单个 pdf 文件中，并且我正在使用 Itextsharp v5.1.1.但它说文件无法打开.它可能已损坏.没有构建错误.但是pdf格式不正确，无法打开.这是我选择完成此操作的顺序.

I am trying to merge 2 crystal reports into single pdf file and I'm using Itextsharp v5.1.1. But it says the document cannot be opened. It might be corrupted. There are no build errors. but the pdf is malformed and cant be opened. Here is the order I chose to accomplish this.

1. 将 Crystal 报表以 pdf 格式导出到 MemoryStream1
2. 将第二个报告导出到 MemoryStream2.
3. 合并内存流
4. 将流以 PDF 格式发送到 Http 输出响应.

这是订单中每个步骤的代码.

Here is the Code for each step in the order.

   /// Get the Dataset from Stored Procedure for the CSSource Report
   dsCS = CSData.GetUSSourceXML(ds_input);
   /// Create the Report of type CSsource
   rptCS = ReportFactory.GetReport(typeof(CSsource));
   rptCS .SetDataSource(dsCS);
   /// Set the Parameters to the CS report
   rptCS .ParameterFields["Parameterid"].CurrentValues.Clear();
   rptCS .SetParameterValue("Parameterid", PID);
   //// Serialize the Object as PDF                    
   msCS=(MemoryStream)rptCS .ExportToStream(ExportFormatType.PortableDocFormat);

对于第 2 步

   /// Get the Dataset from Stored Procedure for the Aden Report
   dsAd = CSData.GetAdden(ds_input);
   /// Create the Report of type Aden
   rptAd = ReportFactory.GetReport(typeof(Aden));
   rptAd.SetDataSource(dsAd );
   /// Set the Parameters to the Aden report
   rptAd.ParameterFields["Parameterid"].CurrentValues.Clear();
   rptAd.SetParameterValue("Parameterid", PID);
   //// Serialize the Object as PDF                    
   msAD = (MemoryStream)rptAd.ExportToStream(ExportFormatType.PortableDocFormat);

第三步

  System.Collections.Generic.List<byte[]> sourceFiles = new List<byte[]>();
  sourceFiles.Add(msCS.ToArray());
  sourceFiles.Add(msAD.ToArray());
  PdfMerger mpdfs = new PdfMerger();
  /// ms is the Memory stream to which both the streams are added
  ms=mpdfs.MergeFiles(sourceFiles);

MergeFiles方法如下

MergeFiles method is as follows

 public MemoryStream MergeFiles(Generic.List<byte[]> sourceFiles)
    {
        Document document = new Document();
        MemoryStream output = new MemoryStream();

        try
        {
            // Initialize pdf writer
            PdfWriter writer = PdfWriter.GetInstance(document, output);
            //writer.PageEvent = new PdfPageEvents();

            // Open document to write
            document.Open();
            PdfContentByte content = writer.DirectContent;

            // Iterate through all pdf documents
            for (int fileCounter = 0; fileCounter < sourceFiles.Count; 
                   fileCounter++)
            {
                // Create pdf reader
                PdfReader reader = new PdfReader(sourceFiles[fileCounter]);
                int numberOfPages = reader.NumberOfPages;

                // Iterate through all pages
                for (int currentPageIndex = 1; currentPageIndex <=
                                   numberOfPages; currentPageIndex++)
                {
                    // Determine page size for the current page
                    document.SetPageSize(
                       reader.GetPageSizeWithRotation(currentPageIndex));

                    // Create page
                    document.NewPage();
                    PdfImportedPage importedPage =
                      writer.GetImportedPage(reader, currentPageIndex);


                    // Determine page orientation
                    int pageOrientation = 
                      reader.GetPageRotation(currentPageIndex);
                    if ((pageOrientation == 90) || (pageOrientation == 270))
                    {
                     content.AddTemplate(importedPage, 0, -1f, 1f, 0, 0,
                     reader.GetPageSizeWithRotation(currentPageIndex).Height);
                    }
                    else
                    {
                    content.AddTemplate(importedPage, 1f, 0, 0, 1f, 0, 0);
                    }
                }
            }
        }
        catch (Exception exception)
        {
        throw new Exception("There has an unexpected exception" +
        " occured during the pdf merging process.", exception);
        }
        finally
        {
           // document.Close();
        }
        return output;
    }

将内存流序列化为 PDF 的步骤 4

Step 4 to Serialize the Memory stream as PDF

  // ms is the memory stream which is to be converted to PDF
  Response.Clear();
        Response.ClearContent();
        Response.ClearHeaders();
        Response.ContentType = "application/pdf";
        Response.Charset = string.Empty;
        Response.AddHeader("Content-Disposition", 
        "attachment; filename=" + 
        "Application of " + FullName.Trim() + ".pdf");
        //Write the file directly to the HTTP content output stream.
        Response.OutputStream.Write(ms.ToArray(), 0, 
               Convert.ToInt32(ms.Length));
        Response.OutputStream.Flush();
        Response.OutputStream.Close();
        rptCS.Close();
        rptCS.Dispose();
        rptAd.Close();
        rptAd.Dispose();

感谢所有帮助我解决此问题的开发人员.这是紧急的，因为它必须在一两天内投入生产.请回复.

Thanks for all those Developers helping me with this. This is Urgent because it has to go production in a day or 2. Please respond.

钱达南.

推荐答案

这里有一个简单的合并方法，将PDF文件复制到一个PDF中.我在合并 pdf 时经常使用这种方法.希望对您有所帮助.

Here's a simple merge method that copies PDF files into one PDF. I use this method quite often when merging pdfs. Hope it helps.

    public MemoryStream MergePdfForms(List<byte[]> files)
    {
        if (files.Count > 1)
        {
            PdfReader pdfFile;
            Document doc;
            PdfWriter pCopy;
            MemoryStream msOutput = new MemoryStream();

            pdfFile = new PdfReader(files[0]);

            doc = new Document();
            pCopy = new PdfSmartCopy(doc, msOutput);

            doc.Open();

            for (int k = 0; k < files.Count; k++)
            {
                pdfFile = new PdfReader(files[k]);
                for (int i = 1; i < pdfFile.NumberOfPages + 1; i++)
                {
                    ((PdfSmartCopy)pCopy).AddPage(pCopy.GetImportedPage(pdfFile, i));
                }
                pCopy.FreeReader(pdfFile);
            }

            pdfFile.Close();
            pCopy.Close();
            doc.Close();

            return msOutput;
        }
        else if (files.Count == 1)
        {
            return new MemoryStream(files[0]);
        }

        return null;
    }

第 4 步尝试:

        rptCS.Close();
        rptCS.Dispose();
        rptAd.Close();
        rptAd.Dispose();

        Response.Clear();
        Response.ContentType = "application/pdf";
        Response.AddHeader("Content-Disposition", 
    "attachment; filename=" + 
    "Application of " + FullName.Trim() + ".pdf");
        Response.BinaryWrite(ms.ToArray());
        ApplicationInstance.CompleteRequest();

这篇关于合并内存流以在 c# 中创建 http PDF 响应的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！