C# 关于 xmlreader xmldocument 和xpath 之间的性能比较

来源：互联网发布：概预算软件破解版编辑：程序博客网时间：2024/06/01 07:28

下面列出微软.net类库提供的读写xml文件个类及其特点：
类名称优点缺点XmlReader快速、高效、可扩展只读，只向前，需要人工验证XmlDocument可往返、可读写、支持XPath筛选比XmlReader慢XPathNavigator可往返，支持XPath和XSLT只读XPathDocument比XmlDocument，优化支持XPath和XSLT比XmlReader慢

本文提到的XmlReader也是微软类库中的一个类，它的特点是快速高效，并且可扩展，缺点是只读。

本人关于这三个做了一个性能测试

条件：做100000次，每次都进行XML的加载和一个节点的读取，所共的时间如下

xpath: 03.265625

dom: 02.625

xmlreader: 0.140625

其中xpath和dom比较类似，大部分时间都在加载XML上，节点查找倒是挺快的，而xmlreader则是边加载边查找，不需要完全加载完才开始查找节点，可以用于大容量的XML读取，便代码编写上没有前两个快捷

           DateTime dt1, dt2;
            string linkId;
            dt1 = DateTime.Now;
            for (int i = 0; i < 100000; i++)
            {
                linkId = XPathTest(strXml);
            }
            dt2 = DateTime.Now;
            Console.WriteLine("XPathTest: {0}", dt2 - dt1);
            dt1 = DateTime.Now;
            for (int i = 0; i < 100000; i++)
            {
                linkId = DOMTest(strXml);
            }
            dt2 = DateTime.Now;
            Console.WriteLine("DOMTest: {0}", dt2 - dt1);
            dt1 = DateTime.Now;
            for (int i = 0; i < 100000; i++)
            {
                linkId = XmlReaderTest(strXml);
            }
            dt2 = DateTime.Now;
            Console.WriteLine("XmlReaderTest: {0}", dt2 - dt1);
            //XmlStream.Close();
            Console.ReadLine();

#region XPathTest
        static string XPathTest(string strXml)
        {
            XmlDocument XmlDoc = new XmlDocument();
            XmlDoc.LoadXml(strXml);

            //XmlNode linkId0 = XmlDoc.SelectSingleNode("Response/SessionID");
            //XmlNode linkId1 = XmlDoc.SelectSingleNode("Response/Result/Item/LastFeed");
            //XmlNode linkId2 = XmlDoc.SelectSingleNode("Response/Result/Item/LandStatus");
            //XmlNode linkId3 = XmlDoc.SelectSingleNode("Response/Result/Item/AnimalID");
            //XmlNode linkId4 = XmlDoc.SelectSingleNode("Response/Result/Item/RaiseTime");
            //XmlNode linkId5 = XmlDoc.SelectSingleNode("Response/Result/Item/AnimalName");

            XmlNode linkId = XmlDoc.SelectSingleNode("Response/Result/Item/LandID");
            return linkId.InnerXml;
        }
        #endregion

        #region DOMTest
        static string DOMTest(string strXml)
        {
            XmlDocument XmlDoc = new XmlDocument();
            XmlDoc.LoadXml(strXml);

            //XmlNode linkId0 = XmlDoc["Response"]["SessionID"];
            //XmlNode linkId1 = XmlDoc["Response"]["Result"]["Item"]["LastFeed"];
            //XmlNode linkId2 = XmlDoc["Response"]["Result"]["Item"]["LandStatus"];
            //XmlNode linkId3 = XmlDoc["Response"]["Result"]["Item"]["AnimalID"];
            //XmlNode linkId4 = XmlDoc["Response"]["Result"]["Item"]["RaiseTime"];
            //XmlNode linkId5 = XmlDoc["Response"]["Result"]["Item"]["AnimalName"];

            XmlNode linkId = XmlDoc["Response"]["Result"]["Item"]["LandID"];
            return linkId.InnerXml;
        }
        #endregion

        #region XmlReaderTest
        static string XmlReaderTest(string strXml)
        {
            string restr = "";

            MemoryStream XmlStream = new MemoryStream();
            byte[] bytes = Encoding.UTF8.GetBytes(strXml);
            XmlStream.Write(bytes, 0, bytes.Length);

            XmlStream.Position = 0;
            XmlTextReader reader = new XmlTextReader(new StreamReader(XmlStream));
            while (reader.Read() && reader.Name != "Response") ;
            while (reader.Read() && reader.Name != "Result") ;
            while (reader.Read() && reader.Name != "Item") ;
            while (reader.Read() && reader.Name != "LandID") ;
            restr = reader.ReadString();

XmlStream.Close();

            return restr;
        }
        #endregion