如何从C#中的Windows窗体应用程序"打开"pdf等文件

private void btnOpenPdf_Click(object sender, EventArgs e)
{
    // 打开文件对话框，选择PDF文件
    OpenFileDialog openFileDialog = new OpenFileDialog();
    openFileDialog.Filter = "PDF文件|*.pdf";
    if (openFileDialog.ShowDialog() == DialogResult.OK)
    {
        // 读取PDF文件
        PdfDocument pdfDocument = PdfReader.Open(openFileDialog.FileName, PdfDocumentOpenMode.Import);

        // 将PDF文件转换为HTML
        StringBuilder htmlString = new StringBuilder();
        foreach (PdfPage pdfPage in pdfDocument.Pages)
        {
            XGraphics graphics = XGraphics.CreateMeasureContext(new XSize(pdfPage.Width, pdfPage.Height), XGraphicsUnit.Point);
            pdfPage.Render(graphics, XGraphics.FromPdfPage(pdfPage));
        }

        // 在WebBrowser控件中显示HTML
        webBrowser.DocumentText = htmlString.ToString();
    }
}