c# - ASP.Net Core 3.0 SignalR HubConnection.InvokeAsync 抛出 : The JSON property name for 'whatever' collides with another property

Question

我的应用程序中使用了以下通过 SignalR 连接进行通信的 DTO/POCO 类:

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

这在 ASP.Net Core 2.2 中运行良好。然而，我在迁移到 3.0 后遇到了以下异常:

 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)

感谢任何建议和见解。

Answer 1

ASP.NET Core 2.2 使用 Newtonsoft.Json，ASP.NET Core 3.0 使用 System.Text.Json。

您可以安装Microsoft.AspNetCore.SignalR.Protocols.NewtonsoftJson nuget包并将其添加到IServiceCollection以切换到Newtonsoft.Json

services.AddSignalR().AddNewtonsoftJsonProtocol();