.net core 将JsonPatchDocument与Blazor一起使用时出现意外错误

我使用Blazor WebAssembly（WASM）客户端通过.NET核心REST API执行更新。为此，我通过HTTP补丁请求发送一个

JsonPatchDocument

，其中

T

是我的应用程序的数据传输对象（DTO）之一

它不起作用。我在Blazor应用程序中返回了一个500内部服务器错误状态代码。我在《邮递员》中得到了更多的细节，但还不足以让我理解这个问题

以下是我的Blazor WASM应用程序中的调用代码：

@code
{
[Parameter]
public int BookId { get; set; } = 101;

private async Task HandleClickAsync()
{
    string newTitle = "How to make JsonPatchDocument work with Blazor - Second Edition";

    var patchDocument = new JsonPatchDocument<Book>()
        .Replace(c => c.Title, newTitle);

    var json = JsonSerializer.Serialize(patchDocument);
    var content = new StringContent(json, Encoding.UTF8, "application/json-patch+json");
    var response = await HttpClient.PatchAsync($"https://localhost:44367/api/books/{BookId}", content);


    if (response.IsSuccessStatusCode)
    {
        // Handle success
    }
    else if (response.StatusCode == HttpStatusCode.NotFound)
    {
        // Handle not found
    }
    else
    {
        // Handle unexpected failures
    }
}
}

当序列化为JSON时，我发送的修补程序文档如下所示：

{"Operations":[{"value":"How to make JsonPatchDocument work with Blazor - Second Edition","OperationType":2,"path":"/Title","op":"replace","from":null}],"ContractResolver":{}}

 public static class HttpClientExtensions
 {
     public static async Task<HttpResponseMessage> PatchAsync<T>(this HttpClient client,
     string requestUri,
     JsonPatchDocument<T> patchDocument)
     where T : class
 {
     var writer = new StringWriter();
     var serializer = new JsonSerializer();
     serializer.Serialize(writer, patchDocument);
     var json = writer.ToString();

     var content = new StringContent(json, Encoding.UTF8, "application/json-patch+json");
     return await client.PatchAsync(requestUri, content);
 }

我在《邮递员》中看到的错误细节是：

System.NotSupportedException: Deserialization of interface types is not supported. Type 'Newtonsoft.Json.Serialization.IContractResolver'
   at System.Text.Json.ThrowHelper.ThrowNotSupportedException_DeserializeCreateObjectDelegateIsNull(Type invalidType)
   at System.Text.Json.JsonSerializer.HandleStartObject(JsonSerializerOptions options, ReadStack& state)
   at System.Text.Json.JsonSerializer.ReadCore(JsonSerializerOptions options, Utf8JsonReader& reader, ReadStack& readStack)
   at System.Text.Json.JsonSerializer.ReadCore(JsonReaderState& readerState, Boolean isFinalBlock, ReadOnlySpan`1 buffer, JsonSerializerOptions options, ReadStack& readStack)
   at System.Text.Json.JsonSerializer.ReadAsync[TValue](Stream utf8Json, Type returnType, JsonSerializerOptions options, CancellationToken cancellationToken)
   at Microsoft.AspNetCore.Mvc.Formatters.SystemTextJsonInputFormatter.ReadRequestBodyAsync(InputFormatterContext context, Encoding encoding)
   at Microsoft.AspNetCore.Mvc.Formatters.SystemTextJsonInputFormatter.ReadRequestBodyAsync(InputFormatterContext context, Encoding encoding)
   at Microsoft.AspNetCore.Mvc.ModelBinding.Binders.BodyModelBinder.BindModelAsync(ModelBindingContext bindingContext)
   at Microsoft.AspNetCore.Mvc.ModelBinding.ParameterBinder.BindModelAsync(ActionContext actionContext, IModelBinder modelBinder, IValueProvider valueProvider, ParameterDescriptor parameter, ModelMetadata metadata, Object value)
   at Microsoft.AspNetCore.Mvc.Controllers.ControllerBinderDelegateProvider.<>c__DisplayClass0_0.<<CreateBinderDelegate>g__Bind|0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeInnerFilterAsync>g__Awaited|13_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResourceFilter>g__Awaited|24_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResourceExecutedContextSealed context)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeFilterPipelineAsync()
--- End of stack trace from previous location where exception was thrown ---
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
   at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
   at Microsoft.AspNetCore.Builder.Extensions.MapWhenMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Builder.Extensions.MapMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

HEADERS
=======
Accept: */*
Accept-Encoding: gzip, deflate, br
Cache-Control: no-cache
Connection: keep-alive
Content-Length: 175
Content-Type: application/json
Host: localhost:44367
User-Agent: PostmanRuntime/7.26.3
Postman-Token: b4444f41-b80f-4ef5-92d5-2416d68d471e

System.NotSupportedException:不支持接口类型的反序列化。键入“Newtonsoft.Json.Serialization.IContractResolver”
位于System.Text.Json.ThrowHelper.ThrownNotSupportedException_反序列化CreateObjectDelegateIsNull（类型invalidType）
位于System.Text.Json.JsonSerializer.handleStarObject（JsonSerializerOptions选项，ReadStack和state）
位于System.Text.Json.JsonSerializer.ReadCore（JsonSerializerOptions选项、Utf8JsonReader和reader、ReadStack和ReadStack）
位于System.Text.Json.JsonSerializer.ReadCore（JsonReaderState和readerState、布尔值isFinalBlock、ReadOnlySpan`1缓冲区、JsonSerializerOptions选项、ReadStack和ReadStack）
在System.Text.Json.JsonSerializer.ReadAsync[TValue]（流utf8Json，类型returnType，JsonSerializerOptions选项，CancellationToken CancellationToken）
位于Microsoft.AspNetCore.Mvc.Formatters.SystemTextJsonInputFormatter.ReadRequestBodyAsync（InputFormatterContext，编码）
位于Microsoft.AspNetCore.Mvc.Formatters.SystemTextJsonInputFormatter.ReadRequestBodyAsync（InputFormatterContext，编码）
位于Microsoft.AspNetCore.Mvc.ModelBinding.Binders.BodyModelBinder.BindModelAsync（ModelBindingContext绑定上下文）
位于Microsoft.AspNetCore.Mvc.ModelBinding.ParameterBinder.BindModelAsync（ActionContext ActionContext、IModelBinder modelBinder、IValueProvider valueProvider、ParameterDescriptor参数、ModelMetadata元数据、对象值）
在Microsoft.AspNetCore.Mvc.Controllers.ControllerBinderDelegateProvider.c_uuDisplayClass0_0.d.MoveNext（）中
---来自引发异常的上一个位置的堆栈结束跟踪---
在Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.g_u等待| 13_0（ControllerActionInvoker invoker，Task lastTask，State next，Scope Scope，Object State，Boolean isCompleted）
在Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g_|24_0（ResourceInvoker invoker、Task lastTask、State next、Scope Scope、Object State、Boolean isCompleted）
位于Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow（ResourceExecutedContextSealed上下文）
位于Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next（状态和下一步、范围和范围、对象和状态、布尔值和isCompleted）
在Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeFilterPipelineAsync（）中
---来自引发异常的上一个位置的堆栈结束跟踪---
在Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g|u waiting | 17|0（ResourceInvoker invoker，Task Task，IDisposable作用域）
位于Microsoft.AspNetCore.Routing.EndpointMiddleware.g_uwaitRequestTask | 6_0（端点、任务请求任务、ILogger记录器）
位于Microsoft.AspNetCore.Builder.Extensions.MapWhenMiddleware.Invoke（HttpContext上下文）
位于Microsoft.AspNetCore.Builder.Extensions.MapMiddleware.Invoke（HttpContext上下文）
位于Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke（HttpContext上下文）
标题
=======
接受：*/*
接受编码：gzip，deflate，br
缓存控制：没有缓存
连接：保持活力
内容长度：175
内容类型：application/json
主机：本地主机：44367
用户代理：PostmanRuntime/7.26.3
邮递代币：b4444f41-b80f-4ef5-92d5-2416d68d471e

我的任何项目都不直接依赖Newtonsoft。不过，我不知道我引用的Microsoft库是否依赖于Newtonsoft。这个错误表明他们可能会这样做

在GitHub上的这个小存储库中可以观察到这种行为：

有人知道它为什么不工作和/或什么能解决它吗

---

谢谢

我设法解决了这个难题，Pavel和Enet的意见非常有用，谢谢

对于其他有相同问题的人，您需要了解以下内容来解决此问题：

到目前为止（2020年末），将.NET核心从

Newtonsoft.Json

移动到

System.Text.Json

的努力还没有完成。包

Microsoft.AspNetCore.JsonPatch

仍然依赖于

Newtonsoft.Json

NET核心开发团队知道GitHub在报告这方面存在很多问题。但它们都没有采取任何行动就被关闭了。显然，将

Microsoft.AspNetCore.JsonPatch

切换到

System.Text.Json

需要付出太多的努力

将Newtonsoft用于

JsonPatch

es，但不用于Web API/server项目的

Startup

类中应使用的任何其他内容。请特别注意

GetJsonPatchInputFormatter

helper方法的使用，该方法在

Startup.ConfigureServices

但这本身可能无法解决Blazor WASM/客户端项目将收到的50X和40X HTTP错误，因为如果使用

System.Text.Json

序列化

JsonPatch

，它会在Json字符串的末尾添加一个空的

ContractResolver

对象（看起来像

，“ContractResolver”：{}

），它在服务器端中断。由于某些原因，该请求与您所做的任何控制器路由都不匹配

要解决这个问题，还必须在Blazor客户端上使用

Newtonsoft.Json

。你不必事事都用它；你只需要使用

System.NotSupportedException: Deserialization of interface types is not supported. Type 'Newtonsoft.Json.Serialization.IContractResolver'
   at System.Text.Json.ThrowHelper.ThrowNotSupportedException_DeserializeCreateObjectDelegateIsNull(Type invalidType)
   at System.Text.Json.JsonSerializer.HandleStartObject(JsonSerializerOptions options, ReadStack& state)
   at System.Text.Json.JsonSerializer.ReadCore(JsonSerializerOptions options, Utf8JsonReader& reader, ReadStack& readStack)
   at System.Text.Json.JsonSerializer.ReadCore(JsonReaderState& readerState, Boolean isFinalBlock, ReadOnlySpan`1 buffer, JsonSerializerOptions options, ReadStack& readStack)
   at System.Text.Json.JsonSerializer.ReadAsync[TValue](Stream utf8Json, Type returnType, JsonSerializerOptions options, CancellationToken cancellationToken)
   at Microsoft.AspNetCore.Mvc.Formatters.SystemTextJsonInputFormatter.ReadRequestBodyAsync(InputFormatterContext context, Encoding encoding)
   at Microsoft.AspNetCore.Mvc.Formatters.SystemTextJsonInputFormatter.ReadRequestBodyAsync(InputFormatterContext context, Encoding encoding)
   at Microsoft.AspNetCore.Mvc.ModelBinding.Binders.BodyModelBinder.BindModelAsync(ModelBindingContext bindingContext)
   at Microsoft.AspNetCore.Mvc.ModelBinding.ParameterBinder.BindModelAsync(ActionContext actionContext, IModelBinder modelBinder, IValueProvider valueProvider, ParameterDescriptor parameter, ModelMetadata metadata, Object value)
   at Microsoft.AspNetCore.Mvc.Controllers.ControllerBinderDelegateProvider.<>c__DisplayClass0_0.<<CreateBinderDelegate>g__Bind|0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeInnerFilterAsync>g__Awaited|13_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResourceFilter>g__Awaited|24_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResourceExecutedContextSealed context)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeFilterPipelineAsync()
--- End of stack trace from previous location where exception was thrown ---
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
   at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
   at Microsoft.AspNetCore.Builder.Extensions.MapWhenMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Builder.Extensions.MapMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

HEADERS
=======
Accept: */*
Accept-Encoding: gzip, deflate, br
Cache-Control: no-cache
Connection: keep-alive
Content-Length: 175
Content-Type: application/json
Host: localhost:44367
User-Agent: PostmanRuntime/7.26.3
Postman-Token: b4444f41-b80f-4ef5-92d5-2416d68d471e

 public static class HttpClientExtensions
 {
     public static async Task<HttpResponseMessage> PatchAsync<T>(this HttpClient client,
     string requestUri,
     JsonPatchDocument<T> patchDocument)
     where T : class
 {
     var writer = new StringWriter();
     var serializer = new JsonSerializer();
     serializer.Serialize(writer, patchDocument);
     var json = writer.ToString();

     var content = new StringContent(json, Encoding.UTF8, "application/json-patch+json");
     return await client.PatchAsync(requestUri, content);
 }