使用C# 11的静态接口方法改进 面向约定 的设计方法

var app = WebApplication.Create();
app.Map("/", (Point point) => point);
app.Run();

public class Point
{
    public double X { get; }
    public double Y { get; }
    public Point(double x, double y)
    {
        X = x;
        Y = y;
    }

    public override string ToString() => $"{X},{Y}";

    public static bool TryParse(string expression, out Point? result)
    {
        result = default;
        var parts = expression.Split(',');
        if (parts.Length != 2) return false;
        if (!double.TryParse(parts[0], out var x) || !double.TryParse(parts[1], out var y)) return false;
        result = new Point(x, y);
        return true;
    }
}

public class Point
{
    ...
    public static ValueTask<Point?> BindAsync(HttpContext httpContext, ParameterInfo parameter)
    {
        Point? result = default;
        var name = parameter.Name;
        var value = httpContext.GetRouteData().Values.TryGetValue(name!, out var v) ? v : httpContext.Request.Query[name!].SingleOrDefault();
        if (value is string expression && TryParse(expression, out var point))
        {
            result = point;
        }
        return new ValueTask<Point?>(result);
    }
}

public interface IBindable<T>
{
    abstract static ValueTask<T?> BindAsync(HttpContext httpContext, ParameterInfo parameter);
}

public interface IParsable<T>
{
    abstract static bool TryParse(string expression, out T? result);
}

public class Point : IBindable<Point>, IParsable<Point>
{
    public double X { get; }
    public double Y { get; }
    public Point(double x, double y)
    {
        X = x;
        Y = y;
    }

    public override string ToString() => $"{X},{Y}";

    public static bool TryParse(string expression, out Point? result)
    {
        result = default;
        var parts = expression.Split(',');
        if (parts.Length != 2) return false;
        if (!double.TryParse(parts[0], out var x) || !double.TryParse(parts[1], out var y)) return false;
        result = new Point(x, y);
        return true;
    }

    public static ValueTask<Point?> BindAsync(HttpContext httpContext, ParameterInfo parameter)
    {
        Point? result = default;
        var name = parameter.Name;
        var value = httpContext.GetRouteData().Values.TryGetValue(name!, out var v) ? v : httpContext.Request.Query[name!].SingleOrDefault();
        if (value is string expression && TryParse(expression, out var point))
        {
            result = point;
        }
        return new ValueTask<Point?>(result);
    }
}

public interface IParsable<TSelf> where TSelf : IParsable<TSelf>?
{
    static TSelf Parse(string s, IFormatProvider? provider);
    static bool TryParse([NotNullWhen(true)] string? s, IFormatProvider? provider, [MaybeNullWhen(false)] out TSelf result);
}

public interface IGrpcService<TService> where TService : class
{
    static abstract void Bind(IServiceBinder<TService> binder);
}

[GrpcService(ServiceName = "Greeter")]
public class GreeterService: IGrpcService<GreeterService>
{
    public Task<HelloReply> SayHelloUnaryAsync(HelloRequest request, ServerCallContext context);

    public async Task<HelloReply> SayHelloClientStreamingAsync(IAsyncStreamReader<HelloRequest> reader, ServerCallContext context);

    public  async Task SayHelloServerStreamingAsync(Empty request, IServerStreamWriter<HelloReply> responseStream, ServerCallContext context);

    public async Task SayHelloDuplexStreamingAsync(IAsyncStreamReader<HelloRequest> reader, IServerStreamWriter<HelloReply> writer, ServerCallContext context);

    public static void Bind(IServiceBinder<GreeterService> binder)
    {
        binder
            .AddUnaryMethod<HelloRequest, HelloReply>(it =>it.SayHelloUnaryAsync(default!,default!), HelloRequest.Parser)
            .AddClientStreamingMethod<HelloRequest, HelloReply>(it => it.SayHelloClientStreamingAsync(default!, default!), HelloRequest.Parser)
            .AddServerStreamingMethod<Empty, HelloReply>(nameof(SayHelloServerStreamingAsync), it => it.SayHelloServerStreamingAsync, Empty.Parser)
            .AddDuplexStreamingMethod<HelloRequest, HelloReply>(nameof(SayHelloDuplexStreamingAsync), it => it.SayHelloDuplexStreamingAsync, HelloRequest.Parser);
    }