序列化中的System.OverflowException

Question

我有一些用于解析Web响应的类：

[DataContract]
public abstract class GYResponse 
{
    [DataMember(Name = "code")]
    public int Code { get; set; }
    [DataMember(Name = "message")]
    public string Message { get; set; }
}

[DataContract]
public class ResponseGetUser : GYResponse
{
    [DataMember(Name = "result")]
    public GYUser Result { get; set; }
}

[DataContract]
public class ResponseGetVenue : GYResponse
{
    [DataMember(Name = "result")]
    public GYVenue Result { get; set; }
}

我使用DataContractJsonSerializer：

GYResponse response_obj = request.Creater.CreateResponseObj(); 
//CreateResponseObj() return ResponseGetUser, ResponseGetVenue etc

using (MemoryStream stream = new MemoryStream(Encoding.Unicode.GetBytes(gyResponse)))
{
    DataContractJsonSerializer serializer = new DataContractJsonSerializer(response_obj.GetType());                   
    response_obj = (GYResponse)serializer.ReadObject(stream);       
}

我排队"System.OverflowException"：

response_obj = (GYResponse)serializer.ReadObject(stream); 

/ checked编译器选项已关闭。并且ReadObject无法抛出此异常。

但如果我重写这些类，那么它可以工作：

[DataContract]
public abstract class GYResponse 
{

}

[DataContract]
public class ResponseGetUser : GYResponse
{
    [DataMember(Name = "result")]
    public GYUser Result { get; set; }
    [DataMember(Name = "code")]
    public int Code { get; set; }
    [DataMember(Name = "message")]
    public string Message { get; set; }
}

[DataContract]
public class ResponseGetVenue : GYResponse
{
    [DataMember(Name = "result")]
    public GYVenue Result { get; set; }
    [DataMember(Name = "code")]
    public int Code { get; set; }
    [DataMember(Name = "message")]
    public string Message { get; set; }
}

我明白这是一个模糊的问题，但无法理解可能是什么问题。什么时候可以抛出这个异常？

更新例外信息：

消息：

 There was an error deserializing the object of type GotYou.RequesterService.ResponseGetInfo. Value was either too large or too small for an Int32.

的InnerException：

at System.Number.ParseInt32(String s, NumberStyles style, NumberFormatInfo info)
   at System.String.System.IConvertible.ToInt32(IFormatProvider provider)
   at System.Convert.ChangeType(Object value, Type conversionType, IFormatProvider provider)
   at System.Runtime.Serialization.Json.DataContractJsonSerializer.ConvertObjectToPrimitiveDataContract(DataContract contract, Object value, XmlObjectSerializerReadContextComplexJson context)
   at System.Runtime.Serialization.Json.DataContractJsonSerializer.ConvertObjectToDataContract(DataContract contract, Object value, XmlObjectSerializerReadContextComplexJson context)
   at System.Runtime.Serialization.Json.ObjectToDataContractConverter.ReadClassDataContractMembers(DataContractJsonSerializer serializer, ClassDataContract dataContract, Dictionary`2 deserialzedValue, Object newInstance, XmlObjectSerializerReadContextComplexJson context)
   at System.Runtime.Serialization.Json.ObjectToDataContractConverter.ReadClassDataContractMembers(DataContractJsonSerializer serializer, ClassDataContract dataContract, Dictionary`2 deserialzedValue, Object newInstance, XmlObjectSerializerReadContextComplexJson context)
   at System.Runtime.Serialization.Json.ObjectToDataContractConverter.ConvertDictionaryToClassDataContract(DataContractJsonSerializer serializer, ClassDataContract dataContract, Dictionary`2 deserialzedValue, XmlObjectSerializerReadContextComplexJson context)
   at System.Runtime.Serialization.Json.DataContractJsonSerializer.ConvertObjectToDataContract(DataContract contract, Object value, XmlObjectSerializerReadContextComplexJson context)
   at System.Runtime.Serialization.Json.ObjectToDataContractConverter.ReadClassDataContractMembers(DataContractJsonSerializer serializer, ClassDataContract dataContract, Dictionary`2 deserialzedValue, Object newInstance, XmlObjectSerializerReadContextComplexJson context)
   at System.Runtime.Serialization.Json.ObjectToDataContractConverter.ConvertDictionaryToClassDataContract(DataContractJsonSerializer serializer, ClassDataContract dataContract, Dictionary`2 deserialzedValue, XmlObjectSerializerReadContextComplexJson context)
   at System.Runtime.Serialization.Json.DataContractJsonSerializer.ConvertObjectToDataContract(DataContract contract, Object value, XmlObjectSerializerReadContextComplexJson context)
   at System.Runtime.Serialization.Json.ObjectToDataContractConverter.ReadClassDataContractMembers(DataContractJsonSerializer serializer, ClassDataContract dataContract, Dictionary`2 deserialzedValue, Object newInstance, XmlObjectSerializerReadContextComplexJson context)
   at System.Runtime.Serialization.Json.ObjectToDataContractConverter.ConvertDictionaryToClassDataContract(DataContractJsonSerializer serializer, ClassDataContract dataContract, Dictionary`2 deserialzedValue, XmlObjectSerializerReadContextComplexJson context)
   at System.Runtime.Serialization.Json.DataContractJsonSerializer.ConvertObjectToDataContract(DataContract contract, Object value, XmlObjectSerializerReadContextComplexJson context)
   at System.Runtime.Serialization.Json.DataContractJsonSerializer.ReadObject(Stream stream)

StrackTrace：

 at System.Runtime.Serialization.Json.DataContractJsonSerializer.ReadObject(Stream stream)
   at GotYou.RequesterService.PostRequester.getResponseCallback(IAsyncResult asynchronousResult)

Json回复：

{
    "code": 0,
    "message": "",
    "result": {
        "uid": "51da997decaa3ca351000000",
        "url": "",
        "nickname": "Smileman",
        "avatar": "\/img\/profile_pics\/users\/51da997decaa3ca351000000\/cache\/avatar48x48.jpg?lastUpdate=1381215566",
        "age": {
            "number": "22",
            "suffix": "года",
            "birthday": "1991-04-17"
        },
        "sex": 1,
        "aboutself": "",
        "premium": true,
        "isFriend": 3,
        "online": {
            "lastVisit": "7 минут назад",
            "status": true
        },
        "features": {
            "car": false,
            "house": false,
            "cash": false,
            "group": true
        },
        "location": {
            "longitude": 36.570838832,
            "latitude": 50.571069472,
            "timestamp": 1381319677
        },
        "bonuses": 8515,
        "address": "",
        "city": {
            "code": "3100000100000",
            "title": ""
        },
        "cover": "\/img\/profile_pics\/users\/51da997decaa3ca351000000\/cache\/hero480x290.jpg?lastUpdate=1381215566",
        "distance": 63.671441859659,
        "paidServices": {
            "vip": true,
            "theming": true,
            "invisible": false,
            "incognito": false,
            "closed": true
        },
        "regdate": "19.08.2013",
        "purpose": {
            "id": "500fa718ecaa3c6e3b000002",
            "title": ""
        }
    }
}

Answer 1

您的数据中的这个数字3100000100000太大，Int32无法容纳它。 Int32的最大正值为2147483647。您可以考虑使用Int64（UInt32也会太小，因为其范围在4294967295处结束。

但是，code字段通常被解释为字符串，因此string数据类型可能是更好的选择，例如：

[DataMember(Name = "code")]
public string Code { get; set; }