validation - Controller.ValidateModel 方法。它是如何工作的？

Question

我有以下模型类:

public abstract class CompanyFormViewModelBase
{
    public CompanyFormViewModelBase()
    {
        Role = new CompanyRoleListViewModel();
        ContactPerson = new PersonListViewModel();
        Sector = new SectorListViewModel();
    }
    [Required]
    [Display(Name = "Company Name")]
    public string CompanyName { get; set; }
    public CompanyRoleListViewModel Role { get; set; }
    [Display(Name = "Contact Name")]
    public PersonListViewModel ContactPerson { get; set; }
    public SectorListViewModel Sector { get; set; }
}
public class AddCompanyViewModel : CompanyFormViewModelBase, IValidatableObject
{
    public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
    {
        PlugandabandonEntities db = new PlugandabandonEntities();
        CompanyName = CompanyName.Trim();

        var results = new List<ValidationResult>();

        if (db.Company.Where(p => p.CompanyName.ToLower() == CompanyName.ToLower()).Count() > 0)
            results.Add(new ValidationResult("Company already exists.", new string[] { "CompanyName" }));
        return results;
    }
}

它适用于“经典”，使用如下:

    [HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult Create(Plugandabandon.ViewModels.AddCompanyViewModel model)
    {
        if (ModelState.IsValid)
        {
            CreateCompany(model);
            return RedirectToAction("Index");
        }
        else
        {
            return View(model);
        }
    }

但我也想将此模型类用于另一个 ajax 表单。
我有以下方法:

   public JsonResult ReturnJsonAddingCompany(string companyName, int roleID, int sectorID, int personID)
    {
        Plugandabandon.ViewModels.AddCompanyViewModel model = new ViewModels.AddCompanyViewModel()
        {
            CompanyName = companyName,
            ContactPerson = new ViewModels.PersonListViewModel()
            {
                SelectedItem = personID
            },
            Role = new ViewModels.CompanyRoleListViewModel()
            {
                SelectedItem = roleID
            },
            Sector = new ViewModels.SectorListViewModel()
            {
                SelectedItem = sectorID
            }
        };

        ValidateModel(model);

        if (ModelState.IsValid)
        {
            CreateCompany(model);
        }
        else
        {
            throw new Exception("Company with such name already exists");
        }

        var list = Utils.CompanyList();
        return Json(list, JsonRequestBehavior.AllowGet);
    }

看着

    ValidateModel(model);

线。如果模型是正确的 - 它工作正常。如果不正确 - 它抛出异常并中断方法的继续执行(并返回异常以查看)。另外，如果我设置断点

public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)

方法，它永远不会在无效模型案例中调用! (使用有效模型调用 Validate 方法)。我想要像“经典”方法这样的行为，只需验证模型，然后验证 ModelState.IsValid。
ValidateModel(model) 的行为对我来说很奇怪，它是一个“黑匣子”......

Answer 1

ValidateModel()如果模型无效，则抛出异常。相反，使用 TryValidateModel()
来自 documentation

The TryValidateModel() is like the ValidateModel() method except that the TryValidateModel() method does not throw an InvalidOperationExceptionexception if the model validation fails.