If（ModelState.IsValid == false）return View（）;或查看（模型）;？

Question

當驗證失敗時，我應該返回哪一個？視圖（）;或查看（模型）; ？

我注意到這兩個工作。這很混亂。

編輯：

public class MoviesController : Controller 
{ 
    MoviesEntities db = new MoviesEntities(); 

    // 
    // GET: /Movies/ 

    public ActionResult Index() 
    { 
     var movies = from m in db.Movies 
        select m; 
     return View(movies.ToList()); 
    } 

    public ActionResult Create() 
    { 
     return View(); 
    } 

    [HttpPost] 
    public ActionResult Create(Movie movie) 
    { 
     if (ModelState.IsValid) 
     { 
      db.AddToMovies(movie); 
      db.SaveChanges(); 

      return RedirectToAction("Index"); 
     } 
     else 
      return View();//View(movie); 
    } 
} 

我Create.aspx：

<% using (Html.BeginForm()) {%> 
    <%: Html.ValidationSummary(true) %> 

    <fieldset> 
     <legend>Fields</legend> 


     <div class="editor-label"> 
      <%: Html.LabelFor(model => model.Title) %> 
     </div> 
     <div class="editor-field"> 
      <%: Html.TextBoxFor(model => model.Title) %> 
      <%: Html.ValidationMessageFor(model => model.Title) %> 
     </div> 

     <div class="editor-label"> 
      <%: Html.LabelFor(model => model.ReleaseDate) %> 
     </div> 
     <div class="editor-field"> 
      <%: Html.TextBoxFor(model => model.ReleaseDate) %> 
      <%: Html.ValidationMessageFor(model => model.ReleaseDate) %> 
     </div> 

     <div class="editor-label"> 
      <%: Html.LabelFor(model => model.Genre) %> 
     </div> 
     <div class="editor-field"> 
      <%: Html.TextBoxFor(model => model.Genre) %> 
      <%: Html.ValidationMessageFor(model => model.Genre) %> 
     </div> 

     <div class="editor-label"> 
      <%: Html.LabelFor(model => model.Price) %> 
     </div> 
     <div class="editor-field"> 
      <%: Html.TextBoxFor(model => model.Price) %> 
      <%: Html.ValidationMessageFor(model => model.Price) %> 
     </div> 

     <p> 
      <input type="submit" value="Create" /> 
     </p> 
    </fieldset> 

<% } %> 

<div> 
    <%: Html.ActionLink("Back to List", "Index") %> 
</div> 

Answer 1

如果要返回視圖是強類型和使用模型倒不如通過這種模式。如果您只是return View()，並且在您嘗試訪問該模型的視圖中，您很可能會獲得NullReferenceException。

下面是一個常見的模式：

public class HomeController: Controller 
{ 
    public ActionResult Index() 
    { 
     var model = FetchModelFromRepo(); 
     return View(model); 
    } 

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

     // TODO: update db 
     return RedirectToAction("index"); 
    } 
}