Question

鉴于以下代码，

[DataContract]
public class TestClass
{
  [DataMember]
  public object _TestVariable;

  public TestClass(object value)
  {
    _TestVariable = value;
  }

  public void Save()
  {
    using (XmlDictionaryWriter writer = XmlDictionaryWriter.CreateTextWriter(new FileStream("test.tmp", FileMode.Create)))
    {
      DataContractSerializer ser = new DataContractSerializer(typeof(TestClass));
      ser.WriteObject(writer, this);
    }
  }
}

public enum MyEnum
{
  One,
  Two,
  Three
}

为什么在_TestVariable设置为枚举值时无法序列化？

new TestClass(1).Save(); // Works
new TestClass("asdfqwer").Save(); // Works
new TestClass(DateTime.UtcNow).Save(); // Works
new TestClass(MyEnum.One).Save(); // Fails

抛出的异常是：

System.Runtime.Serialization.SerializationException : Type 'xxx.MyEnum' with data contract name 'xxx.MyEnum:http://schemas.datacontract.org/2004/07/Tests' is not expected. Consider using a DataContractResolver or add any types not known statically to the list of known types - for example, by using the KnownTypeAttribute attribute or by adding them to the list of known types passed to DataContractSerializer.

Answer 1

您应该在TestClass上使用KnownTypeAttribute。

[DataContract]
[KnownTypeAttribute(typeof(MyEnum))]
public class TestClass

Answer 2

您可以使用的另一个选项是避免必须将KnownType属性放在所有位置，而是使用类型推导为您完成工作。

class Program
{
    static void Main(string[] args)
    {
        TestClass.Create(1).Save(); // Works
        TestClass.Create("asdfqwer").Save(); // Works
        TestClass.Create(DateTime.UtcNow).Save(); // Works
        TestClass.Create(MyEnum.One).Save(); // Fails
    }
}

public class TestClass
{
    public static TestClass<T> Create<T>(T value)
    {
        return new TestClass<T>(value);
    }
}

[DataContract]
public class TestClass<T>
{
    [DataMember]
    public T _TestVariable;

    public TestClass(T value)
    {
        _TestVariable = value;
    }

    public void Save()
    {
        using (XmlDictionaryWriter writer = XmlDictionaryWriter.CreateTextWriter(new MemoryStream()))
        {
            DataContractSerializer ser = new DataContractSerializer(typeof(TestClass<T>));
            ser.WriteObject(writer, this);
        }
    }
}

public enum MyEnum
{
    One,
    Two,
    Three
}

Answer 3

MyEnum未标记为可序列化。将DataContractAttribute添加到MyEnum应该修复它。

C＃DataContractSerializer序列化异常，在对象字段中设置了枚举

3 个答案: