！！十万火急html 转化为word，背景图在word 中不显示

[laoyao1580]

FileStream fs = new FileStream(path, FileMode.OpenOrCreate, FileAccess.ReadWrite);//如
StreamWriter writer = new StreamWriter(fs, System.Text.Encoding.GetEncoding("utf-8"));
string context = GetRequestString(8000, 1, Encoding.GetEncoding("utf-8"), url);
writer.WriteLine(HttpUtility.HtmlDecode(context));
writer.Close();

html里的img标签里的图片能呈现在word里但是背景图片不显示，背景颜色可以显示，急需大侠帮忙。