C#XML序列化 - 领先的问号

Question

问题

通过利用一些样品我在网上找到这里,我已经写了一些XML序列化的方法.

• 方法1:序列化一个Object并返回:(a)类型,(b)xml字符串
• 方法2:取上面的(a)和(b)并返回对象.

我注意到Method1中的xml字符串包含一个前导'？'.当使用Method2重建Object 时,这似乎没问题.

但是当在应用程序中进行一些测试时,有时我们会领先'???' 代替.这导致Method2在尝试重建Object时抛出异常.在这种情况下,'对象'只是一个简单的int.

System.InvalidOperationException未处理Message ="XML文档(1,1)中存在错误." Source ="System.Xml"StackTrace:位于System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader xmlReader,String encodingStyle)的System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader xmlReader,String encodingStyle,XmlDeserializationEvents事件)中. .Serialization.XmlSerializer.Deserialize(Stream stream)位于C:\ Documents and Settings\... Projects\XMLSerialization\Program.cs中的XMLSerialization.Program.DeserializeXmlStringToObject(String xmlString,String objectType):XMLSerialization.Program.Main的第96行(String [] args)在C:\ Documents and Settings\... Projects\XMLSerialization\Program.cs:第49行

是否有人能够解释可能导致这种情况的原因？

示例代码

这是我编写的迷你测试器的示例代码,它是作为VS控制台应用程序运行的.它会显示XML字符串.您还可以取消注释区域以附加额外的前导'??' 重现异常.

using System;
using System.IO;
using System.Text;
using System.Xml;
using System.Xml.Serialization;

namespace XMLSerialization
{
    class Program
    {
        static void Main(string[] args)
        {
            // deserialize to string
            #region int
            object inObj = 5;
            #endregion

            #region string
            //object inObj = "Testing123";
            #endregion

            #region list
            //List inObj = new List();
            //inObj.Add("0:25");
            //inObj.Add("1:26");
            #endregion

            string[] stringArray = SerializeObjectToXmlString(inObj);

            #region include leading ???
            //int indexOfBracket = stringArray[0].IndexOf('<');
            //stringArray[0] = "??" + stringArray[0];
            #endregion

            #region strip out leading ???
            //int indexOfBracket = stringArray[0].IndexOf('<');
            //string trimmedString = stringArray[0].Substring(indexOfBracket);
            //stringArray[0] = trimmedString;
            #endregion

            Console.WriteLine("Input");
            Console.WriteLine("-----");
            Console.WriteLine("Object Type: " + stringArray[1]);
            Console.WriteLine();
            Console.WriteLine("XML String: " + Environment.NewLine + stringArray[0]);
            Console.WriteLine(String.Empty);

             // serialize back to object
            object outObj = DeserializeXmlStringToObject(stringArray[0], stringArray[1]);

            Console.WriteLine("Output");
            Console.WriteLine("------");

            #region int
            Console.WriteLine("Object: " + (int)outObj);
            #endregion

            #region string
            //Console.WriteLine("Object: " + (string)outObj);
            #endregion

            #region list
            //string[] tempArray;
            //List list = (List)outObj;

            //foreach (string pair in list)
            //{
            //    tempArray = pair.Split(':');
            //    Console.WriteLine(String.Format("Key:{0} Value:{1}", tempArray[0], tempArray[1]));
            //}
            #endregion

            Console.Read();
        }

        private static string[] SerializeObjectToXmlString(object obj)
        {
            XmlTextWriter writer = new XmlTextWriter(new MemoryStream(), Encoding.UTF8);
            writer.Formatting = Formatting.Indented;
            XmlSerializer serializer = new XmlSerializer(obj.GetType());
            serializer.Serialize(writer, obj);

            MemoryStream stream = (MemoryStream)writer.BaseStream;
            string xmlString = UTF8ByteArrayToString(stream.ToArray());

            string objectType = obj.GetType().FullName;

            return new string[]{xmlString, objectType};
        }

        private static object DeserializeXmlStringToObject(string xmlString, string objectType)
        {
            MemoryStream stream = new MemoryStream(StringToUTF8ByteArray(xmlString));
            XmlSerializer serializer = new XmlSerializer(Type.GetType(objectType));

            object obj = serializer.Deserialize(stream);

            return obj;
        }

        private static string UTF8ByteArrayToString(Byte[] characters)
        {
            UTF8Encoding encoding = new UTF8Encoding();
            return encoding.GetString(characters);
        }

        private static byte[] StringToUTF8ByteArray(String pXmlString)
        {
            UTF8Encoding encoding = new UTF8Encoding();
            return encoding.GetBytes(pXmlString);
        } 


    }
}

Answer 1

当我以前遇到过这种情况时,它通常与编码有关.我在序列化对象时尝试指定编码.尝试使用以下代码.另外,是否有任何特定原因需要返回string[]数组？我已经改变了使用泛型的方法,因此您不必指定类型.

private static string SerializeObjectToXmlString<T>(T obj)
{
    XmlSerializer xmls = new XmlSerializer(typeof(T));
    using (MemoryStream ms = new MemoryStream())
    {
        XmlWriterSettings settings = new XmlWriterSettings();
        settings.Encoding = Encoding.UTF8;
        settings.Indent = true;
        settings.IndentChars = "\t";
        settings.NewLineChars = Environment.NewLine;
        settings.ConformanceLevel = ConformanceLevel.Document;

        using (XmlWriter writer = XmlTextWriter.Create(ms, settings))
        {
            xmls.Serialize(writer, obj);
        }

        string xml = Encoding.UTF8.GetString(ms.ToArray());
        return xml;
    }
}

private static T DeserializeXmlStringToObject <T>(string xmlString)
{
    XmlSerializer xmls = new XmlSerializer(typeof(T));

    using (MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(xmlString)))
    {
        return (T)xmls.Deserialize(ms);
    }
}

如果您仍然遇到问题,请尝试Encoding.ASCII在您看到的任何地方使用您的代码Encoding.UTF8,除非您有使用UTF8的特定原因.我不确定原因,但在序列化的某些情况下,我看到UTF8编码导致了这个确切的问题.