RDG009：不正確的巢狀 AsParameters

	值
規則識別碼	RDG009
修正程式是中斷或非中斷	不中斷

原因

當端點包含不正確的巢狀 [AsParameters] 時，要求委派產生器便會發出此診斷訊息。

檔案描述

透過 [AsParameters] 屬性用於代理系結的類型不得包含也以 屬性標註的 [AsParameters] 巢狀類型：

using System.Text.Json.Serialization;

var builder = WebApplication.CreateSlimBuilder();

var todos = new[]
{
    new Todo(1, "Write tests", DateTime.UtcNow.AddDays(2)),
    new Todo(2, "Fix tests",DateTime.UtcNow.AddDays(1))
};

builder.Services.AddSingleton(todos);
builder.Services.ConfigureHttpJsonOptions(options =>
{
    options.SerializerOptions.TypeInfoResolverChain.Insert(0, AppJsonSerializerContext.Default);
});

var app = builder.Build();

app.MapGet("/v1/todos/{id}", ([AsParameters] TodoItemRequest request) =>
{
     return request.Todos.ToList().Find(todoItem => todoItem.Id == request.Id) is Todo todo
    ? Results.Ok(todo)
    : Results.NotFound();
});

app.Run();

struct TodoItemRequest
{
    public int Id { get; set; }
    [AsParameters]
    public Todo[] Todos { get; set; }
}

internal record Todo(int Id, string Task, DateTime DueDate);

[JsonSerializable(typeof(Todo[]))]
internal partial class AppJsonSerializerContext : JsonSerializerContext
{
}

如何修正違規

移除巢狀巢狀 AsParameters 屬性：

using System.Text.Json.Serialization;

var builder = WebApplication.CreateSlimBuilder();
var todos = new[]
{
    new Todo(1, "Write tests", DateTime.UtcNow.AddDays(2)),
    new Todo(2, "Fix tests",DateTime.UtcNow.AddDays(1))
};
builder.Services.AddSingleton(todos);
builder.Services.ConfigureHttpJsonOptions(options =>
{
    options.SerializerOptions.TypeInfoResolverChain.Insert(0, AppJsonSerializerContext.Default);
});

var app = builder.Build();

app.MapGet("/v1/todos/{id}", ([AsParameters] TodoItemRequest request) =>
{
    return request.Todos.ToList().Find(todoItem => todoItem.Id == request.Id) is Todo todo
    ? Results.Ok(todo)
    : Results.NotFound();
});

app.Run();

struct TodoItemRequest
{
    public int Id { get; set; }
    //[AsParameters]
    public Todo[] Todos { get; set; }
}

internal record Todo(int Id, string Task, DateTime DueDate);

[JsonSerializable(typeof(Todo[]))]
internal partial class AppJsonSerializerContext : JsonSerializerContext
{
}

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