设计一个可以阅读PDF文档的xaml和cs

以下是一个简单的可用于阅读PDF文档的XAML和CS代码示例：

XAML代码：

<Window x:Class="PDFReader.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="PDF Reader" Height="450" Width="800">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>
        <StackPanel Grid.Row="0" Orientation="Horizontal" Margin="10">
            <Button x:Name="OpenButton" Content="Open" Click="OpenButton_Click"/>
            <Button x:Name="PrevButton" Content="Prev" Click="PrevButton_Click"/>
            <Button x:Name="NextButton" Content="Next" Click="NextButton_Click"/>
        </StackPanel>
        <Frame Grid.Row="1" x:Name="PDFViewer"/>
    </Grid>
</Window>

CS代码：

using System;
using System.IO;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Navigation;
using Microsoft.Win32;
using PdfiumViewer;

namespace PDFReader
{
    public partial class MainWindow : Window
    {
        private int currentPageIndex = 0;
        private PdfDocument pdfDocument;

        public MainWindow()
        {
            InitializeComponent();
        }

        private void OpenButton_Click(object sender, RoutedEventArgs e)
        {
            OpenFileDialog openFileDialog = new OpenFileDialog();
            openFileDialog.Filter = "PDF files (*.pdf)|*.pdf";
            if (openFileDialog.ShowDialog() == true)
            {
                string filePath = openFileDialog.FileName;
                LoadPDF(filePath);
            }
        }

        private void LoadPDF(string filePath)
        {
            if (pdfDocument != null)
            {
                pdfDocument.Dispose();
            }

            pdfDocument = PdfDocument.Load(filePath);
            currentPageIndex = 0;
            ShowPage(currentPageIndex);
        }

        private void ShowPage(int pageIndex)
        {
            if (pdfDocument != null && pageIndex >= 0 && pageIndex < pdfDocument.PageCount)
            {
                PageViewModel pageViewModel = new PageViewModel(pdfDocument.GetPage(pageIndex));
                PDFViewer.Navigate(pageViewModel);
                PrevButton.IsEnabled = pageIndex > 0;
                NextButton.IsEnabled = pageIndex < pdfDocument.PageCount - 1;
            }
        }

        private void PrevButton_Click(object sender, RoutedEventArgs e)
        {
            if (currentPageIndex > 0)
            {
                currentPageIndex--;
                ShowPage(currentPageIndex);
            }
        }

        private void NextButton_Click(object sender, RoutedEventArgs e)
        {
            if (currentPageIndex < pdfDocument.PageCount - 1)
            {
                currentPageIndex++;
                ShowPage(currentPageIndex);
            }
        }
    }

    public class PageViewModel : PageFunction<PdfPage>
    {
        public PdfPage Page { get; set; }

        public PageViewModel(PdfPage page)
        {
            Page = page;
        }

        protected override void Start()
        {
            OnReturn(new ReturnEventArgs<PdfPage>(Page));
        }
    }
}

这个示例使用了PdfiumViewer库来加载和显示PDF文档。它包含一个按钮用于打开PDF文档，以及前一页和后一页按钮用于切换页面。PDF文档被加载到一个Frame中，通过导航到一个自定义的PageViewModel来显示每一页的内容