.NET 6.0とMagicOnionで実現するgRPC通信（Windowsフォーム）v3

.NET 6.0 の Windowsフォームアプリから、MagicOnion NuGetパッケージを使い、gRPC通信処理を行う前回作成したサンプルは、通信用Modelクラスのメンバに使っている型によっては、Exceptionが発生したり、Colorの値がサーバ側に渡らなかったりする問題が発生していました。
今回作成したサンプルは、クライアント側とサーバ側のアプリ起動時に Resolverを設定することで、それらの問題を解消しています。
ソースコードは GitHub で公開しています。

発生していた問題

通信時に発生していたException


Status(StatusCode="Internal", Detail="Error starting gRPC call. MessagePackSerializationException: Failed to serialize MagicOnion.DynamicArgumentTuple`2[[ClassLibrary1.Model.ModelClassA, ClassLibrary1, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[ClassLibrary1.Model.ModelClassA, ClassLibrary1, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]] value. FormatterNotRegisteredException: System.Drawing.Color is not registered in resolver: MessagePack.Resolvers.StandardResolver", DebugException="MessagePack.MessagePackSerializationException: Failed to serialize MagicOnion.DynamicArgumentTuple`2[[ClassLibrary1.Model.ModelClassA, ClassLibrary1, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[ClassLibrary1.Model.ModelClassA, ClassLibrary1, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]] value.
 ---> MessagePack.FormatterNotRegisteredException: System.Drawing.Color is not registered in resolver: MessagePack.Resolvers.StandardResolver
   at MessagePack.FormatterResolverExtensions.Throw(Type t, IFormatterResolver resolver)
   at MessagePack.Formatters.ClassLibrary1_Model_ModelClassAFormatter3.Serialize(MessagePackWriter& writer, ModelClassA value, MessagePackSerializerOptions options)
   at MessagePack.Formatters.MagicOnion_DynamicArgumentTuple`2\[\[ClassLibrary1_Model_ModelClassA\, ClassLibrary1\]\,\[ClassLibrary1_Model_ModelClassA\, ClassLibrary1\]\]Formatter2.Serialize(MessagePackWriter& writer, DynamicArgumentTuple`2 value, MessagePackSerializerOptions options)
   at MessagePack.MessagePackSerializer.Serialize[T](MessagePackWriter& writer, T value, MessagePackSerializerOptions options)
   --- End of inner exception stack trace ---
   at MessagePack.MessagePackSerializer.Serialize[T](MessagePackWriter& writer, T value, MessagePackSerializerOptions options)
   at MessagePack.MessagePackSerializer.Serialize[T](IBufferWriter`1 writer, T value, MessagePackSerializerOptions options, CancellationToken cancellationToken)
   at MagicOnion.Serialization.MessagePackMagicOnionSerializerProvider.MessagePackMagicOnionSerializer.Serialize[T](IBufferWriter`1 writer, T& value)
   at MagicOnion.GrpcMethodHelper.<>c__DisplayClass9_0`1.<CreateBoxedMarshaller>b__0(Box`1 obj, SerializationContext ctx)
   at Grpc.Net.Client.StreamExtensions.WriteMessageAsync[TMessage](Stream stream, GrpcCall call, TMessage message, Action`2 serializer, CallOptions callOptions)
   at Grpc.Net.Client.Internal.PushUnaryContent`2.WriteMessageCore(ValueTask writeMessageTask)
   at System.Net.Http.Http2Connection.Http2Stream.SendRequestBodyAsync(CancellationToken cancellationToken)
   at System.Net.Http.Http2Connection.SendAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
   at System.Net.Http.HttpConnectionPool.SendWithVersionDetectionAndRetryAsync(HttpRequestMessage request, Boolean async, Boolean doRequestAuth, CancellationToken cancellationToken)
   at System.Net.Http.RedirectHandler.SendAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
   at Grpc.Net.Client.Internal.GrpcCall`2.RunCall(HttpRequestMessage request, Nullable`1 timeout)")


   場所 MagicOnion.Client.ResponseContextRaw`2.<FromRawResponseToResponseAsync>d__20.MoveNext()
   場所 MagicOnion.UnaryResult`1.<UnwrapResponse>d__11.MoveNext()

Status(StatusCode="Internal", Detail="Error starting gRPC call. MessagePackSerializationException: Failed to serialize MagicOnion.DynamicArgumentTuple`2[[ClassLibrary1.Model.ModelClassA, ClassLibrary1, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[ClassLibrary1.Model.ModelClassA, ClassLibrary1, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]] value. FormatterNotRegisteredException: System.Drawing.Color is not registered in resolver: MessagePack.Resolvers.StandardResolver", DebugException="MessagePack.MessagePackSerializationException: Failed to serialize MagicOnion.DynamicArgumentTuple`2[[ClassLibrary1.Model.ModelClassA, ClassLibrary1, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[ClassLibrary1.Model.ModelClassA, ClassLibrary1, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]] value.

---> MessagePack.FormatterNotRegisteredException: System.Drawing.Color is not registered in resolver: MessagePack.Resolvers.StandardResolver

at MessagePack.FormatterResolverExtensions.Throw(Type t, IFormatterResolver resolver)

at MessagePack.Formatters.ClassLibrary1_Model_ModelClassAFormatter3.Serialize(MessagePackWriter& writer, ModelClassA value, MessagePackSerializerOptions options)

at MessagePack.Formatters.MagicOnion_DynamicArgumentTuple`2\[\[ClassLibrary1_Model_ModelClassA\, ClassLibrary1\]\,\[ClassLibrary1_Model_ModelClassA\, ClassLibrary1\]\]Formatter2.Serialize(MessagePackWriter& writer, DynamicArgumentTuple`2 value, MessagePackSerializerOptions options)

at MessagePack.MessagePackSerializer.Serialize[T](MessagePackWriter& writer, T value, MessagePackSerializerOptions options)

--- End of inner exception stack trace ---

at MessagePack.MessagePackSerializer.Serialize[T](MessagePackWriter& writer, T value, MessagePackSerializerOptions options)

at MessagePack.MessagePackSerializer.Serialize[T](IBufferWriter`1 writer, T value, MessagePackSerializerOptions options, CancellationToken cancellationToken)

at MagicOnion.Serialization.MessagePackMagicOnionSerializerProvider.MessagePackMagicOnionSerializer.Serialize[T](IBufferWriter`1 writer, T& value)

at MagicOnion.GrpcMethodHelper.<>c__DisplayClass9_0`1.<CreateBoxedMarshaller>b__0(Box`1 obj, SerializationContext ctx)

at Grpc.Net.Client.StreamExtensions.WriteMessageAsync[TMessage](Stream stream, GrpcCall call, TMessage message, Action`2 serializer, CallOptions callOptions)

at Grpc.Net.Client.Internal.PushUnaryContent`2.WriteMessageCore(ValueTask writeMessageTask)

at System.Net.Http.Http2Connection.Http2Stream.SendRequestBodyAsync(CancellationToken cancellationToken)

at System.Net.Http.Http2Connection.SendAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)

at System.Net.Http.HttpConnectionPool.SendWithVersionDetectionAndRetryAsync(HttpRequestMessage request, Boolean async, Boolean doRequestAuth, CancellationToken cancellationToken)

at System.Net.Http.RedirectHandler.SendAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)

at Grpc.Net.Client.Internal.GrpcCall`2.RunCall(HttpRequestMessage request, Nullable`1 timeout)")

場所 MagicOnion.Client.ResponseContextRaw`2.<FromRawResponseToResponseAsync>d__20.MoveNext()

場所 MagicOnion.UnaryResult`1.<UnwrapResponse>d__11.MoveNext()

Resolverを追加することで解消

クライアント側

サーバ側

通信時にColorの値がサーバ側に渡らない

ColorFormatter/ColorResolverクラスを作成することで解消

ライブラリ側

クライアント側

サーバ側

MagicOnion ライブラリ側

ソースコード構成

MessagePack内部の ColorFormatter/ColorResolverを使うと、サーバからクライアントへは値が渡っても、クライアントからサーバへは値が渡らない、バグがあるので自作しています。

ソースコード変更内容を解説

/Formatter/ColorFormatter.cs

Color型を処理できるFormatterを追加。


using MessagePack;
using MessagePack.Formatters;
using System.Drawing;

namespace ClassLibrary1.Interface
{
    public class ColorFormatter : IMessagePackFormatter<Color>
    {
        public static readonly IMessagePackFormatter<Color> Instance = new ColorFormatter();

        public void Serialize(ref MessagePackWriter writer, Color value, MessagePackSerializerOptions options)
        {
            writer.WriteInt32(value.ToArgb());
        }

        public Color Deserialize(ref MessagePackReader reader, MessagePackSerializerOptions options)
        {
            return Color.FromArgb(reader.ReadInt32());
        }
    }
}

using MessagePack;

using MessagePack.Formatters;

using System.Drawing;

namespace ClassLibrary1.Interface

{

public class ColorFormatter : IMessagePackFormatter<Color>

{

public static readonly IMessagePackFormatter<Color> Instance = new ColorFormatter();

public void Serialize(ref MessagePackWriter writer, Color value, MessagePackSerializerOptions options)

{

writer.WriteInt32(value.ToArgb());

}

public Color Deserialize(ref MessagePackReader reader, MessagePackSerializerOptions options)

{

return Color.FromArgb(reader.ReadInt32());

}

/Formatter/ColorResolver.cs

Color型を処理できるResolverを追加。


using MessagePack;
using MessagePack.Formatters;
using System.Drawing;

namespace ClassLibrary1.Interface
{
    public class ColorResolver : IFormatterResolver
    {
        public static IFormatterResolver Instance = new ColorResolver();

        public IMessagePackFormatter<T> GetFormatter<T>()
        {
            return FormatterCache<T>.formatter;
        }

        static class FormatterCache<T>
        {
            public static readonly IMessagePackFormatter<T> formatter;

            static FormatterCache()
            {
                if (typeof(T) == typeof(Color))
                {
                    formatter = (IMessagePackFormatter<T>)ColorFormatter.Instance;
                }
                else
                {
                    formatter = null;
                }
            }
        }
    }
}

using MessagePack;

using MessagePack.Formatters;

using System.Drawing;

namespace ClassLibrary1.Interface

{

public class ColorResolver : IFormatterResolver

{

public static IFormatterResolver Instance = new ColorResolver();

public IMessagePackFormatter<T> GetFormatter<T>()

{

return FormatterCache<T>.formatter;

}

static class FormatterCache<T>

{

public static readonly IMessagePackFormatter<T> formatter;

static FormatterCache()

{

if (typeof(T) == typeof(Color))

{

formatter = (IMessagePackFormatter<T>)ColorFormatter.Instance;

}

else

{

formatter = null;

}

/Model/ModelClassA.cs

通信用Modelクラスに、Color型のメンバを追加。


using MessagePack;
using System.Drawing;

namespace ClassLibrary1.Model
{
    [MessagePackObject]
    public class ModelClassA
    {
        [Key("IntA")] 
        public int IntA { get; set; }

        [Key("StringA")] 
        public string StringA { get; set; }

        [Key("ColorA")]
        public Color ColorA { get; set; }
    }
}

using MessagePack;

using System.Drawing;

namespace ClassLibrary1.Model

{

[MessagePackObject]

public class ModelClassA

{

[Key("IntA")]

public int IntA { get; set; }

[Key("StringA")]

public string StringA { get; set; }

[Key("ColorA")]

public Color ColorA { get; set; }

}

MagicOnion サーバ側

ソースコード構成

ソースコード変更内容を解説

/Program.cs

Resolverを設定する処理を追加。
※Resolverを設定する処理は、サーバ側とクライアント側の両方に追加する必要がある。


using ClassLibrary1.Interface;
using MagicOnion;
using MagicOnion.Server;
using MessagePack.Resolvers;
using MessagePack;

var Resolver = CompositeResolver.Create(
    NativeDateTimeResolver.Instance,
    NativeDecimalResolver.Instance,
    DynamicGenericResolver.Instance,
    ColorResolver.Instance,
    ContractlessStandardResolver.Instance
);
var options = ContractlessStandardResolver.Options.WithResolver(Resolver);
MessagePackSerializer.DefaultOptions = options;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddGrpc();
builder.Services.AddMagicOnion();

var app = builder.Build();

app.MapMagicOnionService();

app.MapGet("/", () => "Hello World!");

app.Run();

using ClassLibrary1.Interface;

using MagicOnion;

using MagicOnion.Server;

using MessagePack.Resolvers;

using MessagePack;

var Resolver = CompositeResolver.Create(

NativeDateTimeResolver.Instance,

NativeDecimalResolver.Instance,

DynamicGenericResolver.Instance,

ColorResolver.Instance,

ContractlessStandardResolver.Instance

);

var options = ContractlessStandardResolver.Options.WithResolver(Resolver);

MessagePackSerializer.DefaultOptions = options;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddGrpc();

builder.Services.AddMagicOnion();

var app = builder.Build();

app.MapMagicOnionService();

app.MapGet("/", () => "Hello World!");

app.Run();

/Services/MyFirstService.cs

Color型のテストデータを追加。


using MagicOnion.Server;
using MagicOnion;
using ClassLibrary1.Interface;
using ClassLibrary1.Model;
using System.Drawing;

namespace WebApplication1.Services
{
    // Implements RPC service in the server project.
    // The implementation class must inherit `ServiceBase<IMyFirstService>` and `IMyFirstService`
    public class MyFirstService : ServiceBase<IMyFirstService>, IMyFirstService
    {
        // `UnaryResult<T>` allows the method to be treated as `async` method.
        public async UnaryResult<int> SumAsync(int x, int y)
        {
            Console.WriteLine($"Received:{x}, {y}");
            return x + y;
        }

        public async UnaryResult<ModelClassA> Sum2Async(ModelClassA modelClassA1, ModelClassA modelClassA2)
        {
            var ModelClassA = new ModelClassA()
            {
                IntA = modelClassA1.IntA + modelClassA2.IntA,
                StringA = modelClassA1.StringA + modelClassA2.StringA,
                ColorA = Color.FromArgb(11, 22, 33)
            };

            return ModelClassA;
        }

    }
}

using MagicOnion.Server;

using MagicOnion;

using ClassLibrary1.Interface;

using ClassLibrary1.Model;

using System.Drawing;

namespace WebApplication1.Services

{

// Implements RPC service in the server project.

// The implementation class must inherit `ServiceBase<IMyFirstService>` and `IMyFirstService`

public class MyFirstService : ServiceBase<IMyFirstService>, IMyFirstService

{

// `UnaryResult<T>` allows the method to be treated as `async` method.

public async UnaryResult<int> SumAsync(int x, int y)

{

Console.WriteLine($"Received:{x}, {y}");

return x + y;

}

public async UnaryResult<ModelClassA> Sum2Async(ModelClassA modelClassA1, ModelClassA modelClassA2)

{

var ModelClassA = new ModelClassA()

{

IntA = modelClassA1.IntA + modelClassA2.IntA,

StringA = modelClassA1.StringA + modelClassA2.StringA,

ColorA = Color.FromArgb(11, 22, 33)

};

return ModelClassA;

}

MagicOnion クライアント側

ソースコード構成

ソースコード変更内容を解説

/Program.cs

Resolverを設定する処理を追加。


using ClassLibrary1.Interface;
using MessagePack.Resolvers;
using MessagePack;

namespace WinFormsApp1
{
    internal static class Program
    {
        /// <summary>
        ///  The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            var Resolver = CompositeResolver.Create(
                NativeDateTimeResolver.Instance,
                NativeDecimalResolver.Instance,
                DynamicGenericResolver.Instance,
                ColorResolver.Instance,
                ContractlessStandardResolver.Instance
            );
            var options = ContractlessStandardResolver.Options.WithResolver(Resolver);
            MessagePackSerializer.DefaultOptions = options;

            // To customize application configuration such as set high DPI settings or default font,
            // see https://aka.ms/applicationconfiguration.
            ApplicationConfiguration.Initialize();
            Application.Run(new Form1());
        }
    }
}

using ClassLibrary1.Interface;

using MessagePack.Resolvers;

using MessagePack;

namespace WinFormsApp1

{

internal static class Program

{

/// <summary>

/// The main entry point for the application.

/// </summary>

[STAThread]

static void Main()

{

var Resolver = CompositeResolver.Create(

NativeDateTimeResolver.Instance,

NativeDecimalResolver.Instance,

DynamicGenericResolver.Instance,

ColorResolver.Instance,

ContractlessStandardResolver.Instance

);

var options = ContractlessStandardResolver.Options.WithResolver(Resolver);

MessagePackSerializer.DefaultOptions = options;

// To customize application configuration such as set high DPI settings or default font,

// see https://aka.ms/applicationconfiguration.

ApplicationConfiguration.Initialize();

Application.Run(new Form1());

}

/Form1.cs

Color型のテストデータを追加。


using ClassLibrary1.Interface;
using ClassLibrary1.Model;
using Grpc.Net.Client;
using MagicOnion.Client;

namespace WinFormsApp1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private async void button1_Click(object sender, EventArgs e)
        {
            // Connect to the server using gRPC channel.
            var channel = GrpcChannel.ForAddress("https://localhost:7061");

            // Create a proxy to call the server transparently.
            var client = MagicOnionClient.Create<IMyFirstService>(channel);

            // Call the server-side method using the proxy.
            var result = (await client.SumAsync(123, 456));
            textBox1.Text = result.ToString();

            var modelClassA1 = new ModelClassA()
            {
                IntA = 1,
                StringA = "aa"
                ,ColorA = Color.FromArgb(10, 20, 30)
            };
            var modelClassA2 = new ModelClassA()
            {
                IntA = 2,
                StringA = "bb"
                ,ColorA = Color.FromArgb(10, 20, 30)
            };
            var resultModelClassA = (await client.Sum2Async(modelClassA1, modelClassA2));
            textBox1.Text = resultModelClassA.IntA.ToString() + " " + resultModelClassA.StringA;
        }
    }
}

using ClassLibrary1.Interface;

using ClassLibrary1.Model;

using Grpc.Net.Client;

using MagicOnion.Client;

namespace WinFormsApp1

{

public partial class Form1 : Form

{

public Form1()

{

InitializeComponent();

}

private async void button1_Click(object sender, EventArgs e)

{

// Connect to the server using gRPC channel.

var channel = GrpcChannel.ForAddress("https://localhost:7061");

// Create a proxy to call the server transparently.

var client = MagicOnionClient.Create<IMyFirstService>(channel);

// Call the server-side method using the proxy.

var result = (await client.SumAsync(123, 456));

textBox1.Text = result.ToString();

var modelClassA1 = new ModelClassA()

{

IntA = 1,

StringA = "aa"

,ColorA = Color.FromArgb(10, 20, 30)

};

var modelClassA2 = new ModelClassA()

{

IntA = 2,

StringA = "bb"

,ColorA = Color.FromArgb(10, 20, 30)

};

var resultModelClassA = (await client.Sum2Async(modelClassA1, modelClassA2));

textBox1.Text = resultModelClassA.IntA.ToString() + " " + resultModelClassA.StringA;

}