Merge PDF Files - Aspose.PDF for .NET

merge-multiple-pdf-files-using-stream.cs

// create PdfFileEditor object
PdfFileEditor pdfEditor = new PdfFileEditor();
// output stream
FileStream outputStream = new FileStream("Merged.pdf", FileMode.Create);
// create array of Streams 
FileStream[] streamArray = new FileStream[3];
streamArray[0] = new FileStream("file1.pdf", FileMode.Open);
streamArray[1] = new FileStream("file2.pdf", FileMode.Open);
streamArray[2] = new FileStream("file3.pdf", FileMode.Open);
// merge files
pdfEditor.Concatenate(streamArray, outputStream);

merge-multiple-pdf-files.cs

// create PdfFileEditor object
PdfFileEditor pdfEditor = new PdfFileEditor();
// create array of PDF files' paths
string[] filesArray = new string[3];
filesArray[0] = "file1.pdf";
filesArray[1] = "file2.pdf";
filesArray[2] = "file3.pdf";
// merge files
pdfEditor.Concatenate(filesArray, "merged.pdf");

merge-two-pdf-files-using-stream.cs

// create PdfFileEditor object
PdfFileEditor pdfEditor = new PdfFileEditor();
// output stream
FileStream outputStream = new FileStream("Merged.pdf", FileMode.Create);
// input streams
FileStream inputStream1 = new FileStream("file1.pdf", FileMode.Open);
FileStream inputStream2 = new FileStream("file2.pdf", FileMode.Open);
// merge files
pdfEditor.Concatenate(inputStream1, inputStream2, outputStream);

merge-two-pdf-files.cs

// create PdfFileEditor object
PdfFileEditor pdfEditor = new PdfFileEditor();
// merge files
pdfEditor.Concatenate("file1.pdf", "file2.pdf", "merged.pdf");