c# - 无法在 asp.net core api 3.1 中将 [FromForm] 枚举与 [EnumMember] 映射

Question

我有一个枚举，并为其值指定了 EnumMemberAttribute:

public enum HireStrategy
{
    [EnumMember(Value = "30-days")]
    Days30,
    [EnumMember(Value = "60-days")]
    Days60,
    [EnumMember(Value = "90-days")]
    Days90
}    

我希望能够使用值 30-days、60-days、90-days 作为我的 api 的输入参数。这是服务配置:

services
    .AddControllers()
    .AddNewtonsoftJson(config =>
    {
        config.SerializerSettings.Converters.Add(new StringEnumConverter(typeof(CamelCaseNamingStrategy)));
    });

services
    .AddMvc();            

我的行动:

[HttpPost("test")]
public async Task<IActionResult> Test(HireStrategy type)
{
    return Ok();
}        

但是，当我尝试使用请求时(通过 postman )https://localhost:44329/api/v1/users/test?type=60-days我收到验证错误，即它甚至没有执行我的操作:

{
    "errors": {
        "type": [
            "The value '60-days' is not valid."
        ]
    },
    "type": "https://tools.ietf.org/html/rfc7231#section-6.5.1",
    "title": "One or more validation errors occurred.",
    "status": 400,
    "traceId": "|b5f15582-4dc901ce029dfb30."
}

当我传递“days60”作为值时，它工作正常。我有什么遗漏的吗？谢谢!

---

更新#1:我尝试禁用 ApiController 验证以查看 newtonsoft 是否处理请求:

services.Configure<ApiBehaviorOptions>(options =>
{
    options.SuppressModelStateInvalidFilter = true;
});            

但参数会映射到默认值，即 Days30

Answer 1

基于答案here这是@dbc 在评论中提供的。我唯一改变的是使用CamelCaseNamingStrategy来确保pascal或camel大小写被视为有效值。

public class EnumMemberConverter<T> : EnumConverter
{
    private readonly CamelCaseNamingStrategy _camelCaseNamingStrategy;

    public EnumMemberConverter(Type type) 
        : base(type) 
    {
        _camelCaseNamingStrategy = new CamelCaseNamingStrategy();
    }

    public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
    {
        var type = typeof(T);

        foreach (var field in type.GetFields())
        {
            if (Attribute.GetCustomAttribute(field, typeof(EnumMemberAttribute)) is EnumMemberAttribute attribute
                && value is string enumValue
                && _camelCaseNamingStrategy.GetPropertyName(attribute.Value, false) == _camelCaseNamingStrategy.GetPropertyName(enumValue, false))
            {
                return field.GetValue(null);
            }
        }          

        return base.ConvertFrom(context, culture, value);
    }
}    

[TypeConverter(typeof(EnumMemberConverter<HireStrategy>))]
public enum HireStrategy
{
    [EnumMember(Value = "30-days")]
    Days30,
    [EnumMember(Value = "60-days")]
    Days60,
    [EnumMember(Value = "90-days")]
    Days90
}