在XML序列化时，如何设置xsi:type ？

[blackfire1024]

比如我要设计一个Test类
在序列化时能有xsi:type
该如何写？

<?xml version="1.0"?>
<Root>
    <Test name="a" xsi:type="Day" />
    <Test name="b" xsi:type="Month" />
    <Test name="c" xsi:type="Year" />
</Root>

利用 XmlAttribute 属性好像不能设置xsi:type

又查了下 MSDN

发现存在 XmlSerializationWriter类，其中有 WriteXsiType 方法

但MSDN同时建议：此 API 支持 .NET Framework 基础结构，不适合在代码中直接使用。

那该如何设置他才能自动序列化？

请熟练XML序列化的朋友指点

[orain]

class Program
{
	static void Main()
	{
		List<Test> tests = new List<Test>();
		tests.Add(new Test("a", "Day"));
		tests.Add(new Test("b", "Month"));
		tests.Add(new Test("c", "Year"));

		XmlSerializer xs = new XmlSerializer(typeof(List<Test>));
		xs.Serialize(Console.Out, tests);		
	}
}

public class Test
{
	[XmlAttribute(AttributeName="name")]
	public string Name { get; set; }
	[XmlAttribute(AttributeName="Type", Namespace="http://www.w3.org/2001/XMLSchema-instance")] //要正确设置 Namespace
	public string Type { get; set; }

	public Test() { }
	public Test(string name, string type)
	{
		Name = name;
		Type = type;		
	}
}

[blackfire1024]

xsi:type的问题已解决

只要使用泛型进行序列化就可以达到效果



但又有新问题了

若在XmlRoot属性指定了NameSpace
则泛型序列化就会失败

代码如下：

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

    [Serializable]
    [XmlRoot(  Namespace = "http://www.csdn.net" )]
    public class Group
    {
        public List<Employee> Employees = new List<Employee>();
    }

    [XmlInclude( typeof( Manager ) )]
    [Serializable]
    public class Employee
    {
        [XmlAttribute]
        public string Name;
    }

    [Serializable]
    public class Manager : Employee
    {
        [XmlAttribute]
        public int Level;
    }


    public class Run
    {
        public static void Main()
        {
            Run test = new Run();
            string path = @"D:\Temp\xsitype.txt";
            test.SerializeObject( path );
            test.DeserializeObject( path );
        }


        public void SerializeObject( string filename )
        {
            using ( FileStream fs = new FileStream( filename, FileMode.Create ) )
            {
                XmlSerializer s = new XmlSerializer( typeof( Group ) );
                TextWriter writer = new StreamWriter( fs );
                Group group = new Group();

                Manager manager = new Manager();
                Employee emp1 = new Employee();
                Employee emp2 = new Employee();

                manager.Name = "Zeus";
                manager.Level = 2;

                emp1.Name = "Ares";

                emp2.Name = "Artemis";

                group.Employees.Add( manager );
               
                s.Serialize( writer, group);
            }
        }

        public void DeserializeObject( string filename )
        {
            FileStream fs = new FileStream( filename, FileMode.Open );
            XmlSerializer x = new XmlSerializer( typeof( Group ) );
            Group g = ( Group ) x.Deserialize( fs );
            Console.Write( "Members:" );

            foreach ( Employee e in g.Employees )
            {
                Console.WriteLine( "\t" + e.Name );
            }
            Console.ReadLine();
        }
    }

错误内容为 “不应是类型 xxxxxx.Manager。使用 XmlInclude 或 SoapInclude 属性静态指定非已知的类型。”

但我已经设置了XmlInclude 如果把NameSpace去除，则运行正常

请问该如何设置

[orain]

XmlSerializer xs = new XmlSerializer(typeof(Group), "http://www.csdn.net");

[blackfire1024]

[Quote=引用 1 楼 orain 的回复:]
C# codeclass Program
{
static void Main()
{
List<Test> tests = new List<Test>();
tests.Add(new Test("a", "Day"));
tests.Add(new Test("b", "Month"));
tests.Add(new Test("c", "Year"));

XmlSerializer xs = new XmlSerializer(typeof(List<Test>));
xs.Serialize(Console.Out, tests);
}
}

public class Test
{
[XmlAttri…
[/Quote]


这个方法有点投机...

但是 我要的是 xsi:type

如果把 Type 改成 type

那么在反序列化的时候 会失败

请看代码

class Program
    {
        static void Main()
        {
            List<Test> tests = new List<Test>();
            tests.Add( new Test( "a", "Day" ) );
            tests.Add( new Test( "b", "Month" ) );
            tests.Add( new Test( "c", "Year" ) );

            string filename = @"C:\temp.txt";
            XmlSerializer xs = new XmlSerializer( typeof( List<Test> ) );
            using ( FileStream fs = new FileStream( filename, FileMode.Create ) )
            {
                xs.Serialize( fs, tests );
            }

            using ( FileStream fs = new FileStream( filename, FileMode.Open ) )
            {
                tests = xs.Deserialize( fs ) as List<Test>;
                foreach ( Test test in tests )
                {
                    Console.WriteLine( test.Name + " " + test.Type );
                }
            }

            Console.ReadLine();
        }
    }

    public class Test
    {
        [XmlAttribute( AttributeName = "name" )]
        public string Name { get; set; }
        [XmlAttribute( AttributeName = "type", Namespace = "http://www.w3.org/2001/XMLSchema-instance" )] //要正确设置 Namespace
        public string Type { get; set; }

        public Test() { }
        public Test( string name, string type )
        {
            Name = name;
            Type = type;
        }
    }

[blackfire1024]

[Quote=引用 3 楼 orain 的回复:]
XmlSerializer xs = new XmlSerializer(typeof(Group), "http://www.csdn.net");
[/Quote]

3Q 完美解决

[orain]

呵呵,我做的时候也觉得是取巧来着,当时我还奇怪一个 Test 元素怎么会对应着那么多类型,因为好久没接触 XML,所以自己也没把握.所以就硬做了一个出来:)
其实你的第二个问题主要是命名空间冲突了,这样可以看得更明显一些:

[XmlInclude(typeof(Manager))]
[XmlType(Namespace="http://www.w3.org/2001/XMLSchema-instance")] //这一句
[Serializable]
public class Employee
{
	[XmlAttribute]
	public string Name;
}

这样的话就不用改这一句了:
XmlSerializer xs = new XmlSerializer(typeof(Group));
我觉得 XML 最烦的就是命名空间了,规则太多,老搞不清楚.幸好用得也不多.

[orain]

不对,反序列化还是有问题，我上面的推断看来不正确.