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我开始使用https://github.com/graphql-dotnet/server在 .NET 中实现 GraphQA ，我编写了一个非常简单的示例应用程序，在运行 Graphiql 时出现以下错误：

fail: Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware[1]
      An unhandled exception has occurred while executing the request.
System.InvalidOperationException: Synchronous operations are disallowed. Call ReadAsync or set AllowSynchronousIO to true instead.
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpRequestStream.Read(Byte[] buffer, Int32 offset, Int32 count)
   at System.IO.StreamReader.ReadBuffer(Span`1 userBuffer, Boolean& readToUserBuffer)
   at System.IO.StreamReader.ReadSpan(Span`1 buffer)
   at System.IO.StreamReader.Read(Char[] buffer, Int32 index, Int32 count)
   at Newtonsoft.Json.JsonTextReader.ReadData(Boolean append, Int32 charsRequired)
   at Newtonsoft.Json.JsonTextReader.ParseValue()
   at Newtonsoft.Json.JsonReader.ReadForType(JsonContract contract, Boolean hasConverter)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize(JsonReader reader, Type objectType, Boolean checkAdditionalContent)
   at Newtonsoft.Json.JsonSerializer.DeserializeInternal(JsonReader reader, Type objectType)
   at Newtonsoft.Json.JsonSerializer.Deserialize[T](JsonReader reader)
   at GraphQL.Server.Transports.AspNetCore.GraphQLHttpMiddleware`1.Deserialize[T](Stream s)
   at GraphQL.Server.Transports.AspNetCore.GraphQLHttpMiddleware`1.InvokeAsync(HttpContext context)
   at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Cors.Infrastructure.CorsMiddleware.InvokeCore(HttpContext context, ICorsPolicyProvider corsPolicyProvider)
   at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

我在这里找到了一个解决方法https://github.com/graphql-dotnet/graphql-dotnet/issues/1116，它指出 IIS/Krestel 的配置需要使用以下命令允许同步 IO：

services.Configure<IISServerOptions>(options =>
{
    options.AllowSynchronousIO = true;
});

我看到https://www.nuget.org/packages/GraphQL.Server.Transports.AspNetCore.NewtonsoftJson仍处于 alpha 阶段，所以我猜我必须使用 .NET Core 3.1 的 JSON 解析器中的构建。

设置的含义是AllowSynchronousIO什么会使服务器可以处理的调用变慢？

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0 回答 0