For HTML2PDF and XML2PDF solution check our PDFDoc Scout ActiveX library instead

using System;
using System.Collections.Generic;
using System.Text;
using Bytescout.PDF;
using System.Diagnostics;

namespace HelloWorld
{
class Program
{
static void Main(string[] args)
{
// Create main PDF Doc Engine
PDFDocEngine engine = new PDFDocEngine("", "");

// Add new document
Document document = engine.AddDocument();

// Append new page to the document
Page page = document.AddPage(PageSizeType.A4, PageOrientationType.LandScape);

// Create new drawing
Drawing drawing = page.AddDrawing();

// font size constant
const int fontSize = 90;

//Add standart font
uint font = document.AddFontStandard(StandardFontType.TimesBold, FontEncodingType.WinAnsi);

// Set Active Font
drawing.SetActiveFont(font, fontSize, false, false);

// X position of the text to draw
int textX = 200;
// Y position of the text to draw
int textY = 250;

// Draw Text
drawing.PlaceText(textX, textY, 0, "Landscape");

// Close drawing
drawing.Close();

// Append new page to the document
page = document.AddPage(PageSizeType.A4, PageOrientationType.Portrait);

// Create new drawing
drawing = page.AddDrawing();

// Set Active Font
drawing.SetActiveFont(font, fontSize, false, false);

// X position of the text to draw
textX = 150;
// Y position of the text to draw
textY = 400;

// Draw Text
drawing.PlaceText(textX, textY, 0, "Portrait");

// Close drawing
drawing.Close();

// Save document
document.Save("PortraitLandscape.pdf");

// open generated PDF document in default PDF viewer installed in Windows
Process.Start("PortraitLandscape.pdf");
}
}
}

Download example source code: bytescoutpdf_page_orientation_portrait_landscape.zip (5 KB)

For HTML2PDF and XML2PDF solution check our PDFDoc Scout ActiveX library instead