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Merge PDF with C# REST API

This short tutorial guides how to merge PDF with C# REST API. You will learn to merge all PDFs with C# REST Interface using the SDK. It will explain all the steps required to develop the application for combining multiple PDF files.

Prerequisite

Steps to Combine PDF with C# Low Code API

  1. Set API key and SID for initializing the PdfApi class object
  2. Create the MergeDocuments object and provide the list of PDF files that you want to merge
  3. Upload all the source PDF files using the UploadFile() method in the PdfApi class
  4. Call the PutMergeDocuments() method to merge all the PDF files into a single destination PDF file
  5. Download and save the output PDF file containing the contents of all the merged PDF files

These steps summarize how to merge PDF online with C# REST API. Use the MergeDocuments class object to create the list of PDF files that you want to merge, and upload all these PDF files to the cloud using the PdfApi.UploadFile() method, and invoke the PutMergeDocuments() method to merge the PDF files online. The API call returns the status OK whereafter you may call the DownloadFile method to retrieve the output PDF file.

Code to Combine PDF Files with C# .NET-based API

using System;
using System.IO;
using Aspose.Pdf.Cloud.Sdk.Api;
using Aspose.Pdf.Cloud.Sdk.Model;
using System.Collections.Generic;
namespace Aspose.PDF.Cloud.Examples.Kb
{
public class PdfTasks
{
public static void SplitPDFFiles()
{
PdfApi pdfApi = new PdfApi("API KEY", "API SID");
String fileName = "sample.pdf";
String format = "pdf";
int from = 1;
int to = 2;
String storage = "";
String folder = "";
try
{
// Upload source file to aspose cloud storage
pdfApi.UploadFile(fileName, new MemoryStream( System.IO.File.ReadAllBytes(fileName)));
// Invoke Aspose.PDF Cloud SDK API to split pdf files
SplitResultResponse apiResponse = pdfApi.PostSplitDocument(fileName, format, from, to, storage, folder);
if (apiResponse.Status.Equals("OK"))
{
// Download created pdf file
foreach(var item in apiResponse.Result.Documents)
{
Stream storageRes = pdfApi.DownloadFile(item.Href);
storageRes.Position = 0;
using (FileStream fileStream = new FileStream(item.Href, FileMode.Create, FileAccess.Write))
{
storageRes.CopyTo(fileStream);
}
}
Console.WriteLine("Split PDF Files, Done!");
Console.ReadKey();
}
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine("error:" + ex.Message + "\n" + ex.StackTrace);
}
}
public static void MergePDFFiles()
{
PdfApi pdfApi = new PdfApi("API KEY", "API SID");// For merging PDF files
String fileName = "sample-merged.pdf";
String storage = "";
String folder = "";
MergeDocuments body = new MergeDocuments(new List<string> { "sample.pdf", "input.pdf" });
try
{
// Load the input Word file
pdfApi.UploadFile("sample.pdf", new MemoryStream(System.IO.File.ReadAllBytes("sample.pdf")));
pdfApi.UploadFile("input.pdf", new MemoryStream(System.IO.File.ReadAllBytes("input.pdf")));
// Merge the PDF files
DocumentResponse apiResponse = pdfApi.PutMergeDocuments(fileName, body);
if (apiResponse != null && apiResponse.Status.Equals("OK"))
{
// Download created pdf file
Stream storageRes = pdfApi.DownloadFile(fileName);
// Save response stream to a file
storageRes.Position = 0;
using (FileStream fileStream = new FileStream(fileName, FileMode.Create, FileAccess.Write))
{
storageRes.CopyTo(fileStream);
}
Console.WriteLine("Merge Multiple PDF Files, Done!");
Console.ReadKey();
}
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine("error:" + ex.Message + "\n" + ex.StackTrace);
}
}
public static void CreatePDF()
{
try
{
PdfApi pdfApi = new PdfApi("2086fd1a0db8175482a26f53c230483e", "fd43bbdc-4e3d-4a75-8847-2138b3ad167e");
DocumentResponse response = pdfApi.PutCreateDocument("newPdfFile");
if (response != null && response.Status.Equals("OK"))
{
Paragraph para = PrepareParagraph("This is first text for new PDF");
pdfApi.PutAddText("newPdfFile", 1, para);
var stream = pdfApi.DownloadFile("newPdfFile", null, null);
using (var fileStream = File.Create("output.pdf"))
{
stream.Seek(0, SeekOrigin.Begin);
stream.CopyTo(fileStream);
}
}
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine("error:" + ex.Message + "\n" + ex.StackTrace);
Console.WriteLine("error:" + ex.Message + "\n" + ex.StackTrace);
}
}
private static Paragraph PrepareParagraph(string text)
{
List<TextLine> textLines = new List<TextLine>();
Segment segment = new Segment(Value: text);
List<Segment> segments = new List<Segment>();
segments.Add(segment);
TextLine textLine = new TextLine(Segments: segments);
textLines.Add(textLine);
Rectangle rectangle = new Rectangle(50.0, 800, 300.0, 850);
Paragraph paragraph = new Paragraph(Lines: textLines, Rectangle: rectangle);
return paragraph;
}
//THIS CODE IS CREATINg INVALID PDF FILE
public static void CreatePDFFromXML()
{
// For complete examples and data files, please go to https://github.com/aspose-pdf/Aspose.Pdf-for-Cloud
PdfApi pdfApi = new PdfApi("2086fd1a0db8175482a26f53c230483e", "fd43bbdc-4e3d-4a75-8847-2138b3ad167e");
String fileName = "input_out.pdf";
String templateFile = "sample.xsl";
String dataFile = "sample.xml";
//String templateType = "xml";
String storageRef = "my_xml";
//String folder = "";
try
{
// Upload source file to aspose cloud storage
byte[] templateFileBytes = System.IO.File.ReadAllBytes(templateFile);
MemoryStream templateFileStream = new MemoryStream(templateFileBytes);
byte[] dataFileBytes = System.IO.File.ReadAllBytes(dataFile);
MemoryStream dataFileStream = new MemoryStream(dataFileBytes);
pdfApi.UploadFile(templateFile, templateFileStream);
pdfApi.UploadFile(dataFile, dataFileStream);
// Invoke Aspose.PDF Cloud SDK API to create Pdf from XML
//DocumentResponse apiResponse = pdfApi.PutCreateDocument(fileName, templateFile, dataFile);
AsposeResponse apiResponse = pdfApi.PutXmlInStorageToPdf(fileName, dataFile, xslFilePath: templateFile, storage: "my_xml");
if (apiResponse != null && apiResponse.Status.Equals("OK"))
{
// Download created pdf file
Stream storageRes = pdfApi.DownloadFile(fileName);
// Save response stream to a file
//storageRes.CopyTo(new FileStream("Sample_out.pdf", FileMode.Create, FileAccess.Write));
storageRes.Position = 0;
SaveStreamToFile(storageRes, fileName);
//Console.WriteLine("Create PDF from XML, Done!");
//Console.ReadKey();
}
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine("error:" + ex.Message + "\n" + ex.StackTrace);
}
}
private static void SaveStreamToFile(Stream sourceStream, string filePath)
{
// Ensure the directory exists
//string directoryPath = Path.GetDirectoryName(filePath);
//if (!Directory.Exists(directoryPath))
//{
// Directory.CreateDirectory(directoryPath);
//}
// Create a FileStream to write the stream to the file
using (FileStream fileStream = new FileStream(filePath, FileMode.Create, FileAccess.Write))
{
sourceStream.CopyTo(fileStream);
}
}
}
}
view raw Merge PDF with C# REST APIi.cs hosted with ❤ by GitHub

This code has taught us how to concatenate PDF files with the C# REST Interface. Use the similar names in the UploadFile() method as used in the list of PDF files in the MergeDocuments object. When you download the resultant PDF file, set the Position parameter to zero otherwise you will not be able to save the file on the disk.

This article has explained how to merge PDF documents online with C# .NET-based API. To create an empty PDF file, refer to the following article: Create a PDF Document with NET REST API.

 

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