C#如何给word文档添加水印

所有代码：

using Spire.Doc;
using Spire.Doc.Documents;
 
namespace Add_Watermark_To_Word
{
 class Program
 {
  static void Main(string[] args)
  {
   Document doc = new Document();
   doc.LoadFromFile("XML文件简介.doc");
 
   //设图片水印
   /*PictureWatermark picture = new PictureWatermark();
   picture.Picture = System.Drawing.Image.FromFile("花朵_2.jpg");
   picture.Scaling = 80;
   doc.Watermark = picture;*/
 
   //设置文本水印
   TextWatermark txtWatermark = new TextWatermark();
   txtWatermark.Text = "Microsoft";
   txtWatermark.FontSize = 90;
   txtWatermark.Layout = WatermarkLayout.Diagonal;
   doc.Watermark = txtWatermark;
 
   doc.SaveToFile("水印.doc");
   System.Diagnostics.Process.Start("水印.doc");
  }
 }
}