.Net核心Web API:如何从接口方法返回验证消息？

[HttpPost]
public IActionResult Create([FromBody] MyModel model)
{
    if (!ModelState.IsValid)
    {
        foreach (var error in ModelState.Values.SelectMany(v => v.Errors))
        {
            ModelState.AddModelError("", error.ErrorMessage);
        }
        return BadRequest(ModelState);
    }

    // 其他逻辑处理

    return Ok();
}

public class ValidateModelAttribute : ActionFilterAttribute
{
    public override void OnActionExecuting(ActionExecutingContext context)
    {
        if (!context.ModelState.IsValid)
        {
            foreach (var error in context.ModelState.Values.SelectMany(v => v.Errors))
            {
                context.ModelState.AddModelError("", error.ErrorMessage);
            }
            context.Result = new BadRequestObjectResult(context.ModelState);
        }
    }
}

[HttpPost]
[ValidateModel]
public IActionResult Create([FromBody] MyModel model)
{
    // 其他逻辑处理

    return Ok();
}

public class MyModel : IValidatableObject
{
    public string Name { get; set; }
    public int Age { get; set; }

    public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
    {
        if (string.IsNullOrEmpty(Name))
        {
            yield return new ValidationResult("Name is required.", new[] { nameof(Name) });
        }

        if (Age < 18)
        {
            yield return new ValidationResult("Age must be at least 18.", new[] { nameof(Age) });
        }
    }
}

[HttpPost]
public IActionResult Create([FromBody] MyModel model)
{
    if (!ModelState.IsValid)
    {
        foreach (var error in ModelState.Values.SelectMany(v => v.Errors))
        {
            ModelState.AddModelError("", error.ErrorMessage);
        }
        return BadRequest(ModelState);
    }

    // 其他逻辑处理

    return Ok();
}