C# 无法反序列化当前JSON对象,为什么会出现此错误?
我正在尝试使用WebApi从我的数据库中获取员工列表,使用以下代码:这是我的客户机MVC应用程序的代码:C# 无法反序列化当前JSON对象,为什么会出现此错误?,c#,json,serialization,asp.net-web-api,C#,Json,Serialization,Asp.net Web Api,我正在尝试使用WebApi从我的数据库中获取员工列表,使用以下代码:这是我的客户机MVC应用程序的代码: string u = "http://localhost:1411/api/EmployeeAPI"; Uri uri = new Uri(u); HttpClient httpClient = new HttpClient(); Task<HttpResponseMessage> response = httpClient.GetAsync(uri); Task.Wait
string u = "http://localhost:1411/api/EmployeeAPI";
Uri uri = new Uri(u);
HttpClient httpClient = new HttpClient();
Task<HttpResponseMessage> response = httpClient.GetAsync(uri);
Task.WaitAll(response);
HttpResponseMessage resposta = response.Result;
var msg = resposta.Content.ReadAsStringAsync().Result;
Employee[] employees = JsonConvert.DeserializeObject<Employee[]>(msg);
return View(employees);
我的员工类别:
namespace DataAccess
{
using System;
using System.Collections.Generic;
public partial class Employee
{
public Employee()
{
this.Products = new HashSet<Product>();
}
public int EmployeeId { get; set; }
public string Title { get; set; }
public string FirstName { get; set; }
public string MiddleName { get; set; }
public string LastName { get; set; }
public byte[] rowguid { get; set; }
public System.DateTimeOffset ModifiedDate { get; set; }
public virtual ICollection<Product> Products { get; set; }
}
}
我的JSon
"{\"Message\":\"An error has occurred.\",\
"ExceptionMessage\":\"The 'ObjectContent`1' type failed to serialize the response body for content type 'application/json; charset=utf-8'.\",\
"ExceptionType\":\"System.InvalidOperationException\",\
"StackTrace\":null,\
"InnerException\":{\
"Message\":\"An error has occurred.\",\
"ExceptionMessage\":\"Self referencing loop detected with type 'System.Data.Entity.DynamicProxies.ProductSubCategory_9EC9A3706390DE6A3B51F713F0DDAC2162AFB5B3FAB8F8587C9A865333A7729A'.
Path '[0].Products[0].ProductSubCategory.ProductCategory.ProductSubCategories'.\",\
"ExceptionType\":\"Newtonsoft.Json.JsonSerializationException\",\
"StackTrace\":\"
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.CheckForCircularReference(JsonWriter writer, Object value, JsonProperty property, JsonContract contract, JsonContainerContract containerContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeList(JsonWriter writer, IWrappedCollection values, JsonArrayContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeList(JsonWriter writer, IWrappedCollection values, JsonArrayContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeList(JsonWriter writer, IWrappedCollection values, JsonArrayContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.Serialize(JsonWriter jsonWriter, Object value)\r\n
at Newtonsoft.Json.JsonSerializer.SerializeInternal(JsonWriter jsonWriter, Object value)\r\n at System.Net.Http.Formatting.JsonMediaTypeFormatter.<>c__DisplayClassd.b__c()\r\n at System.Threading.Tasks.TaskHelpers.RunSynchronously(Action action, CancellationToken token)\"}}"
我认为,如果您查看异常消息,您可能能够深入了解问题 异常消息表示检测到自引用循环。您能否查看/共享模型==>Products[0]。ProductSubCategory.ProductCategory.ProductSubCategories'
我认为您的r标记搞错了。您是否尝试使用List而不是[],并在api列表中使用IEnumerable?可能与我发布的JSON重复,请从stacktrace中检查问题似乎出在Product类的子类别字段或属性上。
namespace DataAccess
{
using System;
using System.Collections.Generic;
public partial class Employee
{
public Employee()
{
this.Products = new HashSet<Product>();
}
public int EmployeeId { get; set; }
public string Title { get; set; }
public string FirstName { get; set; }
public string MiddleName { get; set; }
public string LastName { get; set; }
public byte[] rowguid { get; set; }
public System.DateTimeOffset ModifiedDate { get; set; }
public virtual ICollection<Product> Products { get; set; }
}
}
"{\"Message\":\"An error has occurred.\",\
"ExceptionMessage\":\"The 'ObjectContent`1' type failed to serialize the response body for content type 'application/json; charset=utf-8'.\",\
"ExceptionType\":\"System.InvalidOperationException\",\
"StackTrace\":null,\
"InnerException\":{\
"Message\":\"An error has occurred.\",\
"ExceptionMessage\":\"Self referencing loop detected with type 'System.Data.Entity.DynamicProxies.ProductSubCategory_9EC9A3706390DE6A3B51F713F0DDAC2162AFB5B3FAB8F8587C9A865333A7729A'.
Path '[0].Products[0].ProductSubCategory.ProductCategory.ProductSubCategories'.\",\
"ExceptionType\":\"Newtonsoft.Json.JsonSerializationException\",\
"StackTrace\":\"
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.CheckForCircularReference(JsonWriter writer, Object value, JsonProperty property, JsonContract contract, JsonContainerContract containerContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeList(JsonWriter writer, IWrappedCollection values, JsonArrayContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeList(JsonWriter writer, IWrappedCollection values, JsonArrayContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeList(JsonWriter writer, IWrappedCollection values, JsonArrayContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)\r\n
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.Serialize(JsonWriter jsonWriter, Object value)\r\n
at Newtonsoft.Json.JsonSerializer.SerializeInternal(JsonWriter jsonWriter, Object value)\r\n at System.Net.Http.Formatting.JsonMediaTypeFormatter.<>c__DisplayClassd.b__c()\r\n at System.Threading.Tasks.TaskHelpers.RunSynchronously(Action action, CancellationToken token)\"}}"
"ExceptionMessage\":\"Self referencing loop detected with type 'System.Data.Entity.DynamicProxies.ProductSubCategory_9EC9A3706390DE6A3B51F713F0DDAC2162AFB5B3FAB8F8587C9A865333A7729A'.
Path '[0].Products[0].ProductSubCategory.ProductCategory.ProductSubCategories'.\",\
"ExceptionType\":\"Newtonsoft.Json.JsonSerializationException\",\
"StackTrace\":\"
at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.CheckForCircularReference(JsonWriter writer, Object value, JsonProperty property, JsonContract contract, JsonContainerContract containerContract, JsonProperty containerProperty)