正確的派生類的XML表示形式

Question

因此，我有以下基類和派生類：

[XmlInclude(typeof(Circle))]
[XmlInclude(typeof(Square))]
public class Shape
{
    public int XPos { get; set; }
    public int YPos { get; set; }
}

public class Circle : Shape
{
   public int Radius { get; set; }
}

public class Square : Shape
{
    public int Side { get; set; }
}

如何在XML中表示圓形和正方形，以便可以反序列化為新對象？

我正在努力：

<Shape type="Circle">
   <Radius>10</Radius>
</Shape>
<Shape type="Square">
   <Side>20</Side>
</Shape>

和

<Circle>
   <Radius>10</Radius>
</Circle>
<Square>
   <Side>20</Side>
</Square>

但它們都沒有使用當前派生類（Square或Circle）加載Shape對象。 第一個選項創建一個Square對象。 第二個根本不創建任何對象。 我正在使用C＃MVC4。

[編輯-測試代碼]

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

public class Program
{
    public static void Main()
    {
        var shape = new Shape { XPos = 4, YPos = 5 };
        Console.WriteLine(Serialize(shape));
        Console.WriteLine();

        var circle = new Circle { XPos = 1, YPos = 2, Radius = 3 };
        Console.WriteLine(Serialize(circle));
        Console.WriteLine();

        var square = new Square { XPos = 2, YPos = 1, Side = 5 };

        var ser = Serialize(square);

        Console.WriteLine(square);

        Square sq = Deserialize(ser);

        Console.WriteLine(sq.Side);
    }

    public static string Serialize(Shape objectToSerialize)
    {
        XmlSerializer xmlSerializer = new XmlSerializer(typeof(Shape));
        StringWriter textWriter = new StringWriter();
        xmlSerializer.Serialize(textWriter, objectToSerialize);
        return textWriter.ToString();
    }

    public static Square Deserialize(string ser)
    {
        XmlSerializer serializer = new XmlSerializer(typeof(Square));

        using (StringReader reader = new StringReader(ser))
        {
            return (Square)(serializer.Deserialize(reader));
        }
    }

    [XmlInclude(typeof(Circle))]
    [XmlInclude(typeof(Square))]
    public class Shape
    {
        public int XPos { get; set; }
        public int YPos { get; set; }
    }

    public class Circle : Shape
    {
       public int Radius { get; set; }
    }

    public class Square : Shape
    {
        public int Side { get; set; }
    }
}

Answer 1

您將使用xsi:type聲明Type ，例如xsi:type="Circle"

例

<Shape xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xsi:type="Circle">
  <XPos>1</XPos> 
  <YPos>2</YPos> 
  <Radius>3</Radius> 
</Shape>

我的反序列化測試代碼

var shape = new Circle { XPos = 1, YPos = 2, Radius = 3};
var ser = new XmlSerializer(typeof(Shape));
var xml = string.Empty;

using(var sw = new StringWriter())
{
    ser.Serialize(sw, shape);
    xml = sw.ToString();
}

using (var sr = new StringReader(xml))
{
    var obj = ser.Deserialize(sr);
}

如果您需要一種簡單的方法來返回強類型，則可以添加一個通用方法。

public T DeserializeShape<T>(string xml) where T : Shape
{
    var ser = new XmlSerializer(typeof(Shape));
    using (var sr = new StringReader(xml))
    {
        return (T)ser.Deserialize(sr);
    }
}

var circle = DeserializeShape<Circle>(xml);
var square = DeserializeShape<Square>(xml); // etc....

Answer 2

下面的兩種方法將對形狀進行序列化和反序列化。 反序列化方法是通用的，以允許對不同形狀進行反序列化。

我提供了每個序列化為XML的對象的示例。 這是用於創建示例的點網小提琴 。 它還顯示了如何反序列化對象。

連載

public static string Serialize(Shape objectToSerialize)
{
    XmlSerializer xmlSerializer = new XmlSerializer(typeof(Shape));
    StringWriter textWriter = new StringWriter();

    xmlSerializer.Serialize(textWriter, objectToSerialize);
    return textWriter.ToString();
}

反序列化

public static T Deserialize<T>(string xmlToDeserialize) where T : Shape
{
    XmlSerializer xmlSerializer = new XmlSerializer(typeof(Shape));

    using (StringReader reader = new StringReader(xmlToDeserialize)) {
         return (T)xmlSerializer.Deserialize(reader);
    }
}

示例形狀XML

<?xml version="1.0" encoding="utf-16"?>
<Shape xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <XPos>4</XPos>
  <YPos>5</YPos>
</Shape>

圓形XML示例

<?xml version="1.0" encoding="utf-16"?>
<Shape xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="Circle">
  <XPos>1</XPos>
  <YPos>2</YPos>
  <Radius>3</Radius>
</Shape>

示例Square XML

<?xml version="1.0" encoding="utf-16"?>
<Shape xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="Square">
  <XPos>2</XPos>
  <YPos>1</YPos>
  <Side>5</Side>
</Shape>