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DropDownList在ASP.NETMVC中不能100%工作

asp.net-mvc

Program.X · 技术社区 · 16 年前

背景:

这适用于文本框。但不是下拉列表。我尝试了很多不同的方法,包括:

我有一个ViewModel,比如taht,我有我的列表和我的模型(linqtosql生成的类)作为属性。如:

public class ConsultantRegistrationFormViewModel
{
    public IConsultantRegistration ConsultantRegistration { get; private set; }

    public SelectList Titles { get; private set; }
    public SelectList Countries { get; private set; }
    public SelectList Currencies { get; private set; }
    public int CurrentSection { get; private set; }

    private ConsultantRegistrationFormViewModel(IConsultantRegistration consultantRegistration)
    {
        ConsultantRegistration = consultantRegistration;


        CurrentSection = 1;

        Titles = new SelectList(new string[] { "Mr", "Mrs", "Miss", "Ms", "Dr", "Sir" });
        Countries = new SelectList(countries.Select(q => q.Name));
        Currencies = new SelectList(currencies,"CurrencyCode","FriendlyForm");
    }
}

public class ConsultantRegistrationController : Controller
{
        public IConsultantRegistrationRepository ConsultantRegistrationRepository { get; private set; }
        public ICountryRepository CountryRepository { get; private set; }
    public IEnumerable<ICountry> Countries { get; private set; }

    public ConsultantRegistrationController()
    {
        ConsultantRegistrationRepository = RepositoryFactory.CreateConsultantRegistrationRepository();
        CountryRepository = RepositoryFactory.CreateCountryRepository();

        Countries = CountryRepository.GetCountries().ToArray();
    }


    public ActionResult Edit(Guid id, int sectionIndex)
    {
        IConsultantRegistration consultantRegistration = ConsultantRegistrationRepository.GetConsultantRegistration(id);

        SelectList bankBranchCountriesSelectList = new SelectList(Countries, "BankBranchCountry", "CountryName", consultantRegistration.BankBranchCountry);
        ViewData["bankBranchCountrySelectList"] = bankBranchCountriesSelectList;

        return View(new ConsultantRegistrationFormViewModel(consultantRegistration,sectionIndex,  Countries,Currencies));
    }
}

        <%: Html.DropDownList("ConsultantRegistration.BankBranchCountry",ViewData["bankBranchCountrySelectList"] as SelectList) %>

这给了我一个错误:

不包含具有名称“BankBranchCountry”。

请看一下这个属性的模式:

public interface IConsultantRegistration
{
    Guid ID { get; set; }


    [DisplayName("Branch Country")]
    string BankBranchCountry { get; set; }

}

(我的LINQ到SQL类型ConsultantRegistration已实现IConsultantRegistration)

不过,它似乎试图绑定到错误的类型?

        <%: Html.DropDownList("ConsultantRegistration.BankBranchCountry ",Model.Countries,"(select a Country)") %>

我很好地得到了保存的值,但是我的模型在发布时没有更新。

如果我用这个观点:

        <%: Html.DropDownListFor(model=>model.ConsultantRegistration.BankBranchCountry ",Model.Countries,"(select a Country)") %>

我得到这个列表,它会将所选的值发回,但不会在视图中预先选择模型中当前所选的项。

希望你能帮我弥补我的无知。

2 回复 | 直到 9 年前

Program.X 16 年前

我正在视图中使用ViewData:

                <%: Html.DropDownList("bankBranchCountrySelectList", ViewData["bankBranchCountrySelectList"] as SelectList)%>

我的控制器中包含以下内容:

        public ActionResult Edit(Guid id, int sectionIndex)
        {
            IConsultantRegistration consultantRegistration = ConsultantRegistrationRepository.GetConsultantRegistration(id);

            ViewData["bankBranchCountrySelectList"] = Countries.Select(q => new SelectListItem() { Text = q.Name, Value = q.Name, Selected = (q.Name.Trim().Equals(consultantRegistration.BankBranchCountry, StringComparison.InvariantCultureIgnoreCase)) }); // bankBranchCountriesSelectList;

            return View(new ConsultantRegistrationFormViewModel(consultantRegistration,sectionIndex,  Countries,Currencies));
        }



        [AcceptVerbs(HttpVerbs.Post)]
        public ActionResult Edit(Guid id, int sectionIndex, FormCollection formValues)
        {
            IConsultantRegistration consultantRegistration = ConsultantRegistrationRepository.GetConsultantRegistration(id); 

            UpdateModel(consultantRegistration);
                    ViewData["bankBranchCountrySelectList"] = Countries.Select(q => new SelectListItem() { Text = q.Name, Value = q.Name, Selected = (q.Name.Trim().Equals(consultantRegistration.BankBranchCountry, StringComparison.InvariantCultureIgnoreCase)) });

            IEnumerable<RuleViolation> ruleViolations = consultantRegistration.GetRuleViolations(sectionIndex);
            if (ruleViolations.Count() == 0)
            {

// ...
            }
            else
            {
                ModelState.AddRuleViolations(ruleViolations);
                return View(new ConsultantRegistrationFormViewModel(consultantRegistration, sectionIndex, Countries, Currencies));
            }


    }

不理想,破坏干净的编码。不知道它为什么能工作,但这似乎就是MVC在“约定重于配置”方面的意义所在。

Fenton 16 年前

本文在编写时考虑了多选列表,但这一原则同样适用于单选下拉列表:

http://www.stevefenton.co.uk/Content/Blog/Date/201002/Blog/How-To-Handle-Multiple-Select-Lists-In-ASP-NET-MVC/