RDG013：源属性无效

	值
规则 ID	RDG013
修复是中断修复还是非中断修复	非中断

原因

当终结点包含的路由处理程序的参数包含服务源属性的无效组合时，请求委托生成器会发出此诊断。

规则说明

ASP.NET Core 支持通过依赖项注入解析密钥和非密钥服务。 将服务同时解析为键捡控和非键控服务是不可行的。 以下代码生成诊断并引发运行时错误，显示相同的消息：

using System.Text.Json.Serialization;
using Microsoft.AspNetCore.Mvc;

var builder = WebApplication.CreateSlimBuilder(args);
builder.Services.ConfigureHttpJsonOptions(options =>
{
    options.SerializerOptions.TypeInfoResolverChain.Insert(0,
                                 AppJsonSerializerContext.Default);
});
builder.Services.AddKeyedSingleton<IService, FizzService>("fizz");

var app = builder.Build();

app.MapGet("/fizz", ([FromKeyedServices("fizz")][FromServices] IService service) =>
{
    return Results.Ok(service.Echo());
});

app.Run();

如何解决冲突

将目标参数解析为键控或非键控服务。

using System.Text.Json.Serialization;
using Microsoft.AspNetCore.Mvc;

var builder = WebApplication.CreateSlimBuilder(args);
builder.Services.ConfigureHttpJsonOptions(options =>
{
    options.SerializerOptions.TypeInfoResolverChain.Insert(0,
                                 AppJsonSerializerContext.Default);
});

builder.Services.AddKeyedSingleton<IService, FizzService>("fizz");
builder.Services.AddKeyedSingleton<IService, BuzzService>("buzz");
builder.Services.AddSingleton<IService, FizzBuzzService>();
var app = builder.Build();

app.MapGet("/fizz", ([FromKeyedServices("fizz")] IService service) =>
{
    return Results.Ok(service.Echo());
}); 

app.MapGet("/buzz", ([FromKeyedServices("buzz")] IService service) =>
{
    return Results.Ok(service.Echo());
}); 

app.MapGet("/fizzbuzz", ([FromServices] IService service) =>
{
    return Results.Ok(service.Echo());
});

app.Run();

public interface IService
{
    string Echo();
}

public class FizzService : IService
{
    public string Echo() => "Fizz";
}

public class BuzzService : IService
{
    public string Echo() => "Buzz";
}

public class FizzBuzzService : IService
{
    public string Echo()
    {
        return "FizzBuzz";
    }
}
[JsonSerializable(typeof(string[]))]
internal partial class AppJsonSerializerContext : JsonSerializerContext
{

}

何时禁止显示警告

不应抑制此警告。 禁止显示警告会导致 NotSupportedException 运行时异常 The FromKeyedServicesAttribute is not supported on parameters that are also annotated with IFromServiceMetadata.