Introduction

public static void MergeSpecificPagesInDocument()
{
  Console.WriteLine( "=== MERGE SPECIFIC PAGES IN DOCUMENT===" );

  var file1 = "Tech_Companies.pdf";
  var file2 = "Animals.pdf";
  var outputFileName = "Merged_Specific_Pages.pdf";
  var outputPath = MergeSample.MergeOutputDirectory + outputFileName;

  // Load file1 and file2.
  using( var doc1 = PdfDocument.Load( MergeSample.MergeSampleResourceDirectory + file1 ) )
  {
    using( var doc2 = PdfDocument.Load( MergeSample.MergeSampleResourceDirectory + file2 ) )
    {
      // Make sure doc2 has at least 3 pages.
      if( doc2.Pages.Count > 3 )
      {
        // Merge page0 from doc2 at PageIndex 1 in doc1.
        doc1.Merge( new MergeOptions( doc2, 0, 0 ) { PageIndex = 1 } );
        // Merge page2 to page3 from doc2 at PageIndex 2 in doc1.
        doc1.Merge( new MergeOptions( doc2, 2, 3 ) { PageIndex = 2 } );
      }
      else
      {
        Console.WriteLine( "Warning: doc2 does not have enough pages to merge." );
      }

      // Save the output document.
      doc1.SaveAs( outputPath );
      Console.WriteLine( "Merged specific pages saved to: " + outputPath );
    }
  }
}