6
我有一個ScriptService
幅方法(.NET 3.5)這需要一個抽象基類的一個參數:ASP.NET ScriptService反序列化問題與派生類型
[WebMethod(EnableSession=true)]
[ScriptMethod()]
public bool Test(Item item) { ... }
和:
namespace Namespace {
public abstract class Item
{
public int id;
}
public class Group : Item
{
public Item[] items;
}
public class Instance : Item
{
public string whatever;
}
}
通常,當調用該方法時,item
將是包含Instance
和/或Group
對象的Group
。我從jQuery調用這個服務;我沒有使用Microsoft客戶端框架。調用其他方法工作正常。
問題:當我打電話時,在我的方法被調用之前拋出異常。例如,如果我的電話是:
POST /WebService.asmx/Test HTTP/1.1
Content-Type: application/json; charset=UTF-8
Accept: application/json, text/javascript, */*
{"item":{"id":0,"__type":"Namespace.Group","items":[]}}
...我得到一個InvalidOperationException
:
{"Message":"Operation is not valid due to the current state of the object.","StackTrace":" at System.Web.Script.Serialization.ObjectConverter.ConvertDictionaryToObject(IDictionary`2 dictionary, Type type, JavaScriptSerializer serializer, Boolean throwOnError, Object& convertedObject)\r\n at System.Web.Script.Serialization.ObjectConverter.ConvertObjectToTypeInternal(Object o, Type type, JavaScriptSerializer serializer, Boolean throwOnError, Object& convertedObject)\r\n at System.Web.Script.Serialization.ObjectConverter.ConvertObjectToTypeMain(Object o, Type type, JavaScriptSerializer serializer, Boolean throwOnError, Object& convertedObject)\r\n at System.Web.Script.Serialization.JavaScriptObjectDeserializer.DeserializeInternal(Int32 depth)\r\n at System.Web.Script.Serialization.JavaScriptObjectDeserializer.DeserializeDictionary(Int32 depth)\r\n at System.Web.Script.Serialization.JavaScriptObjectDeserializer.DeserializeInternal(Int32 depth)\r\n at System.Web.Script.Serialization.JavaScriptObjectDeserializer.BasicDeserialize(String input, Int32 depthLimit, JavaScriptSerializer serializer)\r\n at System.Web.Script.Serialization.JavaScriptSerializer.Deserialize(JavaScriptSerializer serializer, String input, Type type, Int32 depthLimit)\r\n at System.Web.Script.Serialization.JavaScriptSerializer.Deserialize[T](String input)\r\n at System.Web.Script.Services.RestHandler.ExecuteWebServiceCall(HttpContext context, WebServiceMethodData methodData)","ExceptionType":"System.InvalidOperationException"}
如果我把JSON對象的__type
成員或將其更改爲Namespace.Item
(並刪除abstract
從Item
修改),異常消失,但由此產生的反序列化的對象顯然有點無用。
我錯過了什麼?
我得到了一個像這樣的錯誤,但我的問題完全不同。我將WCF服務轉換爲ASMX服務。每個人對'__type'屬性使用不同的格式。更新'__type'使用ASMX的格式完全解決了我的問題。 – sparebytes 2012-07-25 20:22:10