c# - 数据契约(Contract)异常。无法序列化

Question

我有以下 WCF 数据契约(Contract):

[DataContract]
public class Occupant
{
    private string _Name;
    private string _Email;
    private string _Organization;
    private string _Badge;

    public Occupant(string name, string badge, string organization)
    {
        Name = name;
        Badge = badge;
        Organization = organization;
    }

    public Occupant(string name, string badge)
    {
        Value = name;
        Key = badge;
    }

    [DataMember]
    public string Key
    {
        get { return _Name; }
        set { _Name = value; }
    }

    [DataMember]
    public string Value
    {
        get { return _Badge; }
        set { _Badge = value; }
    }

    [DataMember]
    public string Name
    {
        get { return _Name; }
        set { _Name = value; }
    }

    [DataMember]
    public string Email
    {
        get { return _Email; }
        set { _Email = value; }
    }

    [DataMember]
    public string Organization
    {
        get { return _Organization; }
        set { _Organization = value; }
    }

    [DataMember]
    public string Badge
    {
        get { return _Badge; }
        set { _Badge = value; }
    }
}

当我尝试通过 Web 浏览器访问此服务(它托管在 IIS 上)时，出现此错误:

System.Runtime.Serialization.InvalidDataContractException: Type 'MyNamespace.Occupant' cannot be serialized. Consider marking it with the DataContractAttribute attribute, and marking all of its members you want serialized with the DataMemberAttribute attribute. If the type is a collection, consider marking it with the CollectionDataContractAttribute.

我的方法之一是返回 Occupant 类型的 List。这会导致它吗？

Answer 1

因为您已经提供了一个或多个初始化构造函数，您还需要添加一个无参数(默认)构造函数。

即您需要添加:

[DataContract]
public class Occupant
{
    // *** Needed only for Serialization
    public Occupant() {}
    ...

这是因为 default constructor disappears当您添加显式构造函数时。

[问题不在于返回 List<Occupant> 的方法，因为方法没有序列化)。]