C# ASP.Net Core 3.0 SignalR HubConnection.InvokeAsync抛出'；不管怎样'；与另一个属性冲突

我的应用程序中使用了以下DTO/POCO类，通过信号机连接进行通信：

class Base {
     public string Value { get; set; }
}
class Child : Base {
     public new string Value { get; set; }
}

这在ASP.NETCore2.2中运行良好。但是，在迁移到3.0后，我遇到了以下异常：

 Error Message:
   System.InvalidOperationException : The JSON property name for 'Biz4x.Frontend.Web.DTO.BoardRates.BoardTemplateWithRatesDTO.Template' collides with another property.
  Stack Trace:
     at System.Text.Json.ThrowHelper.ThrowInvalidOperationException_SerializerPropertyNameConflict(JsonClassInfo jsonClassInfo, JsonPropertyInfo jsonPropertyInfo)
   at System.Text.Json.JsonClassInfo..ctor(Type type, JsonSerializerOptions options)
   at System.Text.Json.JsonSerializerOptions.GetOrAddClass(Type classType)
   at System.Text.Json.WriteStackFrame.Initialize(Type type, JsonSerializerOptions options)
   at System.Text.Json.JsonSerializer.WriteCore(Utf8JsonWriter writer, PooledByteBufferWriter output, Object value, Type type, JsonSerializerOptions options)
   at System.Text.Json.JsonSerializer.WriteValueCore(Utf8JsonWriter writer, Object value, Type type, JsonSerializerOptions options)
   at System.Text.Json.JsonSerializer.Serialize(Utf8JsonWriter writer, Object value, Type inputType, JsonSerializerOptions options)
   at Microsoft.AspNetCore.SignalR.Protocol.JsonHubProtocol.WriteArguments(Object[] arguments, Utf8JsonWriter writer)
   at Microsoft.AspNetCore.SignalR.Protocol.JsonHubProtocol.WriteInvocationMessage(InvocationMessage message, Utf8JsonWriter writer)
   at Microsoft.AspNetCore.SignalR.Protocol.JsonHubProtocol.WriteMessageCore(HubMessage message, IBufferWriter`1 stream)
   at Microsoft.AspNetCore.SignalR.Protocol.JsonHubProtocol.WriteMessage(HubMessage message, IBufferWriter`1 output)
   at Microsoft.AspNetCore.SignalR.Client.HubConnection.SendHubMessage(ConnectionState connectionState, HubMessage hubMessage, CancellationToken cancellationToken)
   at Microsoft.AspNetCore.SignalR.Client.HubConnection.InvokeCore(ConnectionState connectionState, String methodName, InvocationRequest irq, Object[] args, String[] streams, CancellationToken cancellationToken)
   at Microsoft.AspNetCore.SignalR.Client.HubConnection.InvokeCoreAsyncCore(String methodName, Type returnType, Object[] args, CancellationToken cancellationToken)
   at System.Threading.Tasks.ForceAsyncAwaiter`1.GetResult()
   at Microsoft.AspNetCore.SignalR.Client.HubConnection.InvokeCoreAsync(String methodName, Type returnType, Object[] args, CancellationToken cancellationToken)

---

非常感谢您的建议和见解。

ASP.NET Core 2.2正在使用

Newtonsoft.Json

，ASP.NET Core 3.0正在使用

System.Text.Json

您可以安装nuget软件包并将其添加到

IServiceCollection

以切换到

Newtonsoft.Json

services.AddSignalR().AddNewtonsoftJsonProtocol();

public void ConfigureServices(IServiceCollection services)
{
    ...
    services.AddControllers().AddNewtonsoftJson()
    ...
}

---

如果要切换回使用Newtonsoft.Json的先前默认设置，请执行以下操作：

• 安装Microsoft.AspNetCore.Mvc.NewtonsoftJsonNuGet软件包
• 在

  ConfigureServices（）

  中添加对

  AddNewtonsoftJson（）的调用