我在数据合约上有一个knowntype属性，并且不知道如何修改xml以接受这些knowntypes

Question

数据合同示例

[DataContract(Namespace = "namespace")]
[KnownType(typeof(KnownType1))]
public class DataContract
{
    [DataMember(IsRequired = true)]
    public int Value;
}

如何编写xml来使用KnownType1代替DataContract。 我尝试做：（为了简化本示例，我忽略了名称空间和所有其他内容）

<DataContract> 
      <Value> 1</Value>
      <KnownType1> ....</KnownType>
</DataContract>

我也尝试过用KnownType1替换DataContract节点，但是我也不认为这是正确的。

Answer 1

例如，我们遵循DTO：

[DataContract(Namespace = "namespace")]
[KnownType(typeof(KnownType1))]
public class DataContract
{
    [DataMember(IsRequired = true)]
    public int Value;
}

[DataContract(Namespace = "namespace1")]
public sealed class KnownType1 : DataContract
{
    [DataMember(IsRequired = true)]
    public int Value1;
}

为简单起见（我使用XmlTextWriter(Console.Out)打印结果xml），序列化函数如下所示：

private void Serialize<T>(object value)
{
    XmlObjectSerializer serializer = new DataContractSerializer(typeof(T));
    var writer = new XmlTextWriter(Console.Out)
    {
        Formatting = Formatting.Indented
    };
    serializer.WriteObject(writer, value);
}

这是序列化：

[Fact]
public void Test()
{
    Serialize<DataContract>(new KnownType1 { Value = 1, Value1 = 2 });

    Serialize<DataContract>(new DataContract { Value = 1 });
}

结果输出：

<DataContract xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns:d1p1="namespace1" i:type="d1p1:KnownType1" xmlns="namespace">
  <Value>1</Value>
  <d1p1:Value1>2</d1p1:Value1>
</DataContract>

<DataContract xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="namespace">
  <Value>1</Value>
</DataContract>

如您所见， KnownType1 xml包含其他i:type="d1p1:KnownType1"