json - 使用 Newtonsoft JSON 反序列化的 System.TypeLoadException

Question

我真的被难住了。这是我返回的 JSON:

{"ResponseData":[{"ClusterID":"c02f1f5c-c61b-4f2c-ab5a-249966b3cdef","ClusterName":"Northeast","Courses":[{"CourseID":"8ab4f2b3-8160-4d7e-b79f-8d8b58926cc0","CourseName":"Home Course","SubCourses":[{"SubCourseName":"SubCourse1","SubCourseNumber":18}]},{"CourseID":"b3223464-333b-4c54-89c2-23908e0510c9","CourseName":"Away Course","SubCourses":[{"SubCourseName":"SubCourse1","SubCourseNumber":19}]}],"IsHomeCluster":true},"ResponseErrors":[]}

这是我要反序列化的代码:

        JArray jArr = (JArray)JsonConvert.DeserializeObject(json);
        foreach (var item in jArr) {
            foreach (var subitem in item["ResponseData"]) {
                Console.WriteLine (subitem ["ClusterID"]);
            }
        }

项目编译正常，但是当我在模拟器中运行它时，出现此错误:

System.TypeLoadException: A type load exception has occurred. at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize (Newtonsoft.Json.JsonReader reader, System.Type objectType, Boolean checkAdditionalContent) [0x00000] in :0 at Newtonsoft.Json.JsonSerializer.DeserializeInternal (Newtonsoft.Json.JsonReader reader, System.Type objectType) [0x00000] in :0 at Newtonsoft.Json.JsonSerializer.Deserialize (Newtonsoft.Json.JsonReader reader, System.Type objectType) [0x00000] in :0 at Newtonsoft.Json.JsonConvert.DeserializeObject (System.String value, System.Type type, Newtonsoft.Json.JsonSerializerSettings settings) [0x00000] in :0 at Newtonsoft.Json.JsonConvert.DeserializeObject (System.String value) [0x00000] in :0 at AppMultiView.CourseInformationScreen.ViewDidLoad () [0x00029] in /Users/Dan/Desktop/AppTouch_dev /Screens/CourseInformationScreen.cs:48 at (wrapper managed-to-native) MonoTouch.ObjCRuntime.Messaging:void_objc_msgSend_IntPtr_bool (intptr,intptr,intptr,bool) at MonoTouch.UIKit.UINavigationController.PushViewController (MonoTouch.UIKit.UIViewController viewController, Boolean animated) [0x00021] in /Developer/MonoTouch/Source/monotouch/src/UIKit/UINavigationController.g.cs:176 at AppMultiView.HomeScreen.m__2 (System.Object sender, System.EventArgs e) [0x00016] in /Users/Dan/Desktop/AppTouch_dev /Screens/HomeScreen.cs:75 at MonoTouch.UIKit.UIControlEventProxy.Activated () [0x00000] in /Developer/MonoTouch/Source/monotouch/src/UIKit/UIControl.cs:30 at (wrapper managed-to-native) MonoTouch.UIKit.UIApplication:UIApplicationMain (int,string[],intptr,intptr) at MonoTouch.UIKit.UIApplication.Main (System.String[] args, System.String principalClassName, System.String delegateClassName) [0x0004c] in /Developer/MonoTouch/Source/monotouch/src/UIKit/UIApplication.cs:38
at AppMultiView.Application.Main (System.String[] args) [0x00000] in /Users/Dan/Desktop/AppTouch_dev /Main.cs:18

我是否试图反序列化错误的东西？

任何指点将不胜感激。

Answer 1

我不完全确定您所看到的问题是什么。可能只是你的 json 格式错误。

它有帮助，我通常解决这个问题的方法是:

1. 使用类似 http://chris.photobooks.com/json/ 的工具验证 JSON - 在这种情况下，这向我揭示了一个错误 - 您的“ResponseData”数组未终止。固定代码为:

   {"ResponseData":[
       {"ClusterID":"c02f1f5c-c61b-4f2c-ab5a-249966b3cdef","ClusterName":"Northeast",
       "Courses":
       [
       {"CourseID":"8ab4f2b3-8160-4d7e-b79f-8d8b58926cc0","CourseName":"Home Course","SubCourses":
           [{"SubCourseName":"SubCourse1","SubCourseNumber":18}]},
       {"CourseID":"b3223464-333b-4c54-89c2-23908e0510c9","CourseName":"Away Course","SubCourses":
           [{"SubCourseName":"SubCourse1","SubCourseNumber":19}]}
       ],
       "IsHomeCluster":true}
   ]
   ,"ResponseErrors":[]}
   

2. 将更正后的 JSON 复制到 http://json2csharp.com/

   这给了我这样的类(class):

   public class SubCours
   {
       public string SubCourseName { get; set; }
       public int SubCourseNumber { get; set; }
   }
   
   public class Cours
   {
       public string CourseID { get; set; }
       public string CourseName { get; set; }
       public List<SubCours> SubCourses { get; set; }
   }
   
   public class ResponseData
   {
       public string ClusterID { get; set; }
       public string ClusterName { get; set; }
       public List<Cours> Courses { get; set; }
       public bool IsHomeCluster { get; set; }
   }
   
   public class RootObject
   {
       public List<ResponseData> ResponseData { get; set; }
       public List<object> ResponseErrors { get; set; }
   }
   

3. 使用JsonConvert.DeserializeObject<RootObject>(json)获取反序列化的 RootObject

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还有一个新的 JSON 粘贴为类功能可用: http://blogs.msdn.com/b/webdev/archive/2012/12/18/paste-json-as-classes-in-asp-net-and-web-tools-2012-2-rc.aspx