获取DWF页面尺寸

            var width = 0.0;
            var height = 0.0;
            //获取DWF页面尺寸
            using (var zip = new ZipFile(fileName))
            {
                foreach (ZipEntry entry in zip.Entries)
                {
                    if (entry.FileName.Contains("dwf.ePlot_") && Path.GetFileName(entry.FileName) == "descriptor.xml")
                    {
                        var stream = entry.OpenReader();
                        var xml = new XmlDocument();//初始化一个xml实例
                        xml.Load(stream);//载入文件
                        var root = xml.DocumentElement;
                        var nodes = root.ChildNodes;
                        foreach (XmlNode node in nodes)
                        {
                            if (node.Name.Equals("ePlot:Paper"))
                            {
                                double.TryParse(node.Attributes["width"].Value, out width);
                                double.TryParse(node.Attributes["height"].Value, out height);
                                break;
                            }
                        }
                        break;
                    }
                }
            }