.net使用Spire.Doc给word添加自定义水印

using System;
using System.IO;
using Spire.Doc.Documents;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;

protected void Page_Load(object sender, EventArgs e)
    {
        string exeDir = Path.GetDirectoryName("d:") + Path.DirectorySeparatorChar;

        string dataDir = @"C:test";
        //创建图片
        string sImgPath = dataDir + "Spire.Doc自定义水印" + DateTime.Now.ToString("yyyyMMddHHmmss") + ".png";
        WatermarkText.CreateImage(sImgPath, "Spire.Doc自定义水印" + "rn" + DateTime.Now.ToString("yyyy年M月dd日HH时MM分"));
        //添加水印
        test1(dataDir, "test.docx", sImgPath);
        //删除自定义图片
        File.Delete(sImgPath);

    }

private void test1(string dataDir, string sfile, string sImgPath)
    {

        Spire.Doc.Document doc = new Spire.Doc.Document();
        doc.LoadFromFile(dataDir + sfi