ASP.Net MVC 3 ViewModel数据注释

时间:2012-03-27 13:57:53

标签: asp.net-mvc-3 viewmodel data-annotations partial-classes

我正在使用Entity Framework 4.1开发一个ASP.Net MVC 3 Web应用程序,我对使用数据注释进行表单验证感到困惑。 我总是将ViewModel返回给View而不是传递实际对象,因为我意识到这是不好的做法。例如:

public class ViewModelTeam
{
    public Team Team { get; set; }
}

我的视图可能会有类似这样的内容

@model UI.ViewModels.ViewModelTeam

    @Html.HiddenFor(model => model.Team.teamID)


    <div class="editor-label">
        @Html.LabelFor(model => model.Team.description)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.Team.description)
        @Html.ValidationMessageFor(model => model.Team.description)
    </div>

为了验证这个视图,我在部分类中创建了数据注释,如此

[MetadataType(typeof(TeamMetaData))]
public partial class Team
{
    public class TeamMetaData
    {
        [DisplayName("Team Name")]
        [Required(ErrorMessage = "Please enter a Team Name")]
        public object description { get; set; }

然后在我的创建控制器中我有了这个

[HttpPost]
    public ActionResult Create(Team team)
    {
        if (ModelState.IsValid)
        {
           //Add team and redirect
        }

          //Got this far then errors have happened
          //Add Model State Errors


        ViewModelTeam viewModel = new ViewModelTeam
        {
            Team = team            
        };

        return View(viewModel);
    }

现在,这很好用,但是,我读到的关于ViewModel和验证的内容越多,它应该被验证的ViewModel越多,因为在一天结束时,正在显示的是ViewModel在视图中,而不是对象。

因此,我将ViewModel更改为如下所示

public class ViewModelListItem
{

    public int teamID { get; set; }

    [DisplayName("Item Name")]
    [Required(ErrorMessage = "Please enter a Team Name")]
    public string description { get; set; }

我还将创建控制器更改为此

[HttpPost]
    public ActionResult Create(Team team)
    {
        if (ModelState.IsValid)
        {
           //Add team and redirect
        }

          //Got this far then errors have happened
          //Add Model State Errors

        ViewModelTeam viewModel = new ViewModelTeam();
     viewModel.description = team.description;

        return View(viewModel);
    }

再一次,这是有效的,但我感觉第二种方法有点凌乱,或者在第一种方式下效率不高。

我很想听听别人对此的看法。感谢您的帮助,我为这么长的帖子道歉。

1 个答案:

答案 0 :(得分:11)

我总是使用视图模型和AutoMapper来帮助我简化域和视图模型之间的映射。

查看模型:

public class TeamViewModel
{
    [DisplayName("Team Name")]
    [Required(ErrorMessage = "Please enter a Team Name")]
    public string Description { get; set; }
}

然后是常用的模式:

public class TeamsController: Controller
{
    public ActionResult Create()
    {
        var model = new TeamViewModel();
        return View(model);
    }

    [HttpPost]
    public ActionResult Create(TeamViewModel model)
    {
        if (!ModelState.IsValid)
        {
            return View(model);
        }

        Team team = Mapper.Map<TeamViewModel, Team>(model);
        Repository.DoSomethingWithTeam(team);

        return RedirectToAction("Success");
    }
}