WPF:如何在横向模式下打印？

using System;
using System.Printing;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Media;

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }

    private void PrintButton_Click(object sender, RoutedEventArgs e)
    {
        PrintDialog printDialog = new PrintDialog();
        if (printDialog.ShowDialog() == true)
        {
            PrintDocument printDocument = new PrintDocument();
            printDocument.PrintPage += PrintDocument_PrintPage;

            // 设置打印页面的大小和方向
            printDocument.PrintTicket.PageOrientation = PageOrientation.Landscape;
            printDocument.PrintTicket.PageMediaSize = new PageMediaSize(PageMediaSizeName.ISOA4);

            printDialog.PrintDocument(printDocument.DocumentPaginator, "Printing WPF Content");
        }
    }

    private void PrintDocument_PrintPage(object sender, PrintPageEventArgs e)
    {
        // 获取要打印的内容
        UIElement content = ContentToPrint;

        // 获取打印页面的大小
        Size pageSize = new Size(e.PrintableArea.Width, e.PrintableArea.Height);

        // 设置打印内容的位置和大小
        content.Measure(pageSize);
        content.Arrange(new Rect(new Point(0, 0), pageSize));

        // 使用VisualBrush将内容绘制到打印页面
        VisualBrush brush = new VisualBrush(content);
        e.Graphics.DrawRectangle(brush, null, new Rect(new Point(), pageSize));

        // 指示是否还有更多页面需要打印
        e.HasMorePages = false;
    }
}