一下这段代码中 如何在最后将pdf文件用PdfiumViewer库中的pdfViewer1控件显示出来 private void Form1_Load(object sender, EventArgs e) { // 读取 PDF 文件 PdfReader reader = new PdfReader("your_pdf_file.pdf"); int pageCount = reader.NumberOfPages; // 添加水印 for (int i = 1; i <= pageCount; i++) { PdfStamper stamper = new PdfStamper(reader, new FileStream("temp.pdf", FileMode.Create)); // 水印文本 string watermarkText = "This is a watermark text"; // 水印字体 BaseFont bf = BaseFont.CreateFont(BaseFont.HELVETICA, BaseFont.CP1252, BaseFont.NOT_EMBEDDED); Font font = new Font(bf, 32, Font.BOLD, new BaseColor(255, 0, 0, 128)); // 水印位置 Rectangle rect = reader.GetPageSize(i); float x = rect.Width / 2; float y = rect.Height / 2; // 添加水印 PdfContentByte over = stamper.GetOverContent(i); over.SaveState(); over.SetGState(new PdfGState() { FillOpacity = 0.5f, StrokeOpacity = 0.5f }); over.BeginText(); over.SetFontAndSize(font.BaseFont, font.Size); over.SetColorFill(font.Color); over.ShowTextAligned(Element.ALIGN_CENTER, watermarkText, x, y, 45); over.EndText(); over.RestoreState(); stamper.Close(); } // 显示 PDF 文件 axAcroPDF1.src = "temp.pdf"; }

可以使用PdfiumViewer库中的pdfViewer1控件来显示pdf文件。首先，需要将生成的temp.pdf文件加载到pdfViewer1控件中，可以使用以下代码实现：
// 将生成的temp.pdf文件加载到pdfViewer1控件中
pdfViewer1.Document = PdfiumViewer.PdfDocument.Load("temp.pdf");

将上述代码添加到Form1_Load方法的最后即可。完整代码如下：
private void Form1_Load(object sender, EventArgs e)
{
// 读取 PDF 文件
PdfReader reader = new PdfReader("your_pdf_file.pdf");
int pageCount = reader.NumberOfPages;

// 添加水印
for (int i = 1; i <= pageCount; i++)
{
PdfStamper stamper = new PdfStamper(reader, new FileStream("temp.pdf", FileMode.Create));

// 水印文本
string watermarkText = "This is a watermark text";

// 水印字体
BaseFont bf = BaseFont.CreateFont(BaseFont.HELVETICA, BaseFont.CP1252, BaseFont.NOT_EMBEDDED);
Font font = new Font(bf, 32, Font.BOLD, new BaseColor(255, 0, 0, 128));

// 水印位置
Rectangle rect = reader.GetPageSize(i);
float x = rect.Width / 2;
float y = rect.Height / 2;

// 添加水印
PdfContentByte over = stamper.GetOverContent(i);
over.SaveState();
over.SetGState(new PdfGState() { FillOpacity = 0.5f, StrokeOpacity = 0.5f });
over.BeginText();
over.SetFontAndSize(font.BaseFont, font.Size);
over.SetColorFill(font.Color);
over.ShowTextAligned(Element.ALIGN_CENTER, watermarkText, x, y, 45);
over.EndText();
over.RestoreState();

stamper.Close();
}

// 将生成的temp.pdf文件加载到pdfViewer1控件中
pdfViewer1.Document = PdfiumViewer.PdfDocument.Load("temp.pdf");
}