Asp.net mvc 4 如何将ViewModel传递回同一页面_Asp.net Mvc 4_Razor_Asp.net Mvc Viewmodel_Html.beginform

Asp.net mvc 4 如何将ViewModel传递回同一页面

asp.net-mvc-4 razor

Asp.net mvc 4 如何将ViewModel传递回同一页面,asp.net-mvc-4,razor,asp.net-mvc-viewmodel,html.beginform,Asp.net Mvc 4,Razor,Asp.net Mvc Viewmodel,Html.beginform,我正试图让一个HTTPPost为视频页面的评论部分工作，但在回发时遇到了一些困难。正在将保存记录到数据库中，但在重新加载页面时，我无法找到第一次找到的@Model.SelectedMediaItem.Name变量。我的html如下所示： @{ ViewBag.Title = "Screencast"; Layout = "~/Views/Shared/_Layout.cshtml"; } @model Project.ViewModels.MediaViewModel <body onlo

我正试图让一个HTTPPost为视频页面的评论部分工作，但在回发时遇到了一些困难。正在将保存记录到数据库中，但在重新加载页面时，我无法找到第一次找到的@Model.SelectedMediaItem.Name变量。我的html如下所示：

@{
ViewBag.Title = "Screencast";
Layout = "~/Views/Shared/_Layout.cshtml";
}
@model Project.ViewModels.MediaViewModel
<body onload="initialize()">

<div class="container region3wrap_screencast">
  <div class="row content_top_contact">
    <div class="nine columns">
      <ul class="breadcrumbs">
        <li><a href="@Url.Action("Index","Home")">Home</a></li>
        <li><a href="@Url.Action("Index","Media")">Media</a></li>
        <li><a href="@Url.Action("Screencast","Media")">Screencast</a></li>
        <li class="current"><a href="#">@Model.SelectedMediaItem.Name</a></li>
      </ul>
    </div>
  </div>
</div>

<div class="twelve columns leave-comment">
  <h3>Leave a Comment</h3>
  @using(Html.BeginForm("Screencast","Media", FormMethod.Post, Model))
  {              
    <div class="row">
      <div class="six columns">
        <div class="row">
          <div class="six columns">
            @Html.LabelFor(c => c.FeedbackComment.UserID)
            @Html.TextBoxFor(c => c.FeedbackComment.UserID)
          </div>
          <div class="six columns">
            @Html.LabelFor(c => c.FeedbackComment.ContentID)
            @Html.TextBoxFor(c => c.FeedbackComment.ContentID)
          </div>   
          <div class="row">
            <div class="twelve columns">
              @Html.LabelFor(c => c.FeedbackComment.FeedbackString)
              @Html.TextAreaFor(c => c.FeedbackComment.FeedbackString)
            </div>
          </div>        
        </div>
      </div>
    </div>          
    <input type="submit" value="Submit button" class="medium button bottom20"/>
  }
</div>
</body>

  //GET
  public ActionResult Screencast(int ID)
  {                        
    mvm = new ViewModels.MediaViewModel(ID);
    return View(mvm);
  }

  //POST
  [HttpPost]
  public ActionResult Screencast(MediaViewModel mvm)
  {
    Feedback newFeedback= new Feedback();
    newFeedback.UserID = mvm.FeedbackComment.UserID;
    newFeedback.ContentID = mvm.FeedbackComment.ContentID;
    newFeedback.CourseID = null;
    newFeedback.Timestamp = DateTime.Now;
    newFeedback.FeedbackString = mvm.FeedbackComment.FeedbackString;

    //Initialize the Feedback Repository and save changes
    feedbackRepository = new Repository<Feedback>(dbcontext);
    feedbackRepository.Add(newFeedback);
    feedbackRepository.SaveChanges();

    return View(mvm);
  }

public class MediaViewModel
{
    private Repository<Content> contentRepository;
    private Repository<Feedback> feedbackRepository;
    private MetaLearningContext dbcontext;

    public int screencastID { get; set; }

    public IEnumerable<Content> Screencasts { get; set; }
    public IEnumerable<Content> Podcasts { get; set; }
    public IEnumerable<Content> Documents { get; set; }
    public IEnumerable<Feedback> FeedbackComments { get; set; }
    public Content SelectedMediaItem { get; set; }
    public MetaLearningUser User { get; set; }
    public MetaLearningUser FeedbackAuthor { get; set; }
    public Feedback FeedbackComment { get; set; }

    public MediaViewModel()
    {
        this.dbcontext = new MyContext(System.Configuration.ConfigurationManager.ConnectionStrings["MyContext"].ConnectionString);
        this.contentRepository = new Repository<Content>(dbcontext);
        this.feedbackRepository = new Repository<Feedback>(dbcontext);
        this.dbcontext.Configuration.LazyLoadingEnabled = true;

        //Retrieve a list of Screencasts
        Screencasts = contentRepository
            .Get(c => c.ContentTypeID == 1);

        //Retrieve a list of Podcasts
        Podcasts = contentRepository
            .Get(c => c.ContentTypeID == 2);

        //Retrieve a list of Documents
        Documents = contentRepository
            .Get(c => c.ContentTypeID == 3);

    }

    public MediaViewModel(int id)
    {
        this.dbcontext = new MyContext(System.Configuration.ConfigurationManager.ConnectionStrings["MyContext"].ConnectionString);
        this.contentRepository = new Repository<Content>(dbcontext);
        this.feedbackRepository = new Repository<Feedback>(dbcontext);
        this.dbcontext.Configuration.LazyLoadingEnabled = true;

        //Retrieve a list of Screencasts
        Screencasts = contentRepository
            .Get(c => c.ContentTypeID == 1);

        //Retrieve a list of Podcasts
        Podcasts = contentRepository
            .Get(c => c.ContentTypeID == 2);

        //Retrieve a list of Documents
        Documents = contentRepository
            .Get(c => c.ContentTypeID == 3);                       

        //Retrieve selected screencast
        SelectedMediaItem = contentRepository
            .Get(c => c.ContentID == id)
            .FirstOrDefault();              

    }

}

@{
ViewBag.Title=“Screencast”；
Layout=“~/Views/Shared/_Layout.cshtml”；
}
@模型Project.ViewModels.MediaViewModel






留言
@使用（Html.BeginForm（“屏幕广播”，“媒体”，FormMethod.Post，Model））
{              
@LabelFor（c=>c.FeedbackComment.UserID）
@Html.TextBoxFor（c=>c.FeedbackComment.UserID）
@LabelFor（c=>c.FeedbackComment.ContentID）
@TextBoxFor（c=>c.FeedbackComment.ContentID）
@LabelFor（c=>c.FeedbackComment.FeedbackString）
@Html.TextAreaFor（c=>c.FeedbackComment.FeedbackString）
}

我的控制器操作如下：

@{
ViewBag.Title = "Screencast";
Layout = "~/Views/Shared/_Layout.cshtml";
}
@model Project.ViewModels.MediaViewModel
<body onload="initialize()">

<div class="container region3wrap_screencast">
  <div class="row content_top_contact">
    <div class="nine columns">
      <ul class="breadcrumbs">
        <li><a href="@Url.Action("Index","Home")">Home</a></li>
        <li><a href="@Url.Action("Index","Media")">Media</a></li>
        <li><a href="@Url.Action("Screencast","Media")">Screencast</a></li>
        <li class="current"><a href="#">@Model.SelectedMediaItem.Name</a></li>
      </ul>
    </div>
  </div>
</div>

<div class="twelve columns leave-comment">
  <h3>Leave a Comment</h3>
  @using(Html.BeginForm("Screencast","Media", FormMethod.Post, Model))
  {              
    <div class="row">
      <div class="six columns">
        <div class="row">
          <div class="six columns">
            @Html.LabelFor(c => c.FeedbackComment.UserID)
            @Html.TextBoxFor(c => c.FeedbackComment.UserID)
          </div>
          <div class="six columns">
            @Html.LabelFor(c => c.FeedbackComment.ContentID)
            @Html.TextBoxFor(c => c.FeedbackComment.ContentID)
          </div>   
          <div class="row">
            <div class="twelve columns">
              @Html.LabelFor(c => c.FeedbackComment.FeedbackString)
              @Html.TextAreaFor(c => c.FeedbackComment.FeedbackString)
            </div>
          </div>        
        </div>
      </div>
    </div>          
    <input type="submit" value="Submit button" class="medium button bottom20"/>
  }
</div>
</body>

  //GET
  public ActionResult Screencast(int ID)
  {                        
    mvm = new ViewModels.MediaViewModel(ID);
    return View(mvm);
  }

  //POST
  [HttpPost]
  public ActionResult Screencast(MediaViewModel mvm)
  {
    Feedback newFeedback= new Feedback();
    newFeedback.UserID = mvm.FeedbackComment.UserID;
    newFeedback.ContentID = mvm.FeedbackComment.ContentID;
    newFeedback.CourseID = null;
    newFeedback.Timestamp = DateTime.Now;
    newFeedback.FeedbackString = mvm.FeedbackComment.FeedbackString;

    //Initialize the Feedback Repository and save changes
    feedbackRepository = new Repository<Feedback>(dbcontext);
    feedbackRepository.Add(newFeedback);
    feedbackRepository.SaveChanges();

    return View(mvm);
  }

public class MediaViewModel
{
    private Repository<Content> contentRepository;
    private Repository<Feedback> feedbackRepository;
    private MetaLearningContext dbcontext;

    public int screencastID { get; set; }

    public IEnumerable<Content> Screencasts { get; set; }
    public IEnumerable<Content> Podcasts { get; set; }
    public IEnumerable<Content> Documents { get; set; }
    public IEnumerable<Feedback> FeedbackComments { get; set; }
    public Content SelectedMediaItem { get; set; }
    public MetaLearningUser User { get; set; }
    public MetaLearningUser FeedbackAuthor { get; set; }
    public Feedback FeedbackComment { get; set; }

    public MediaViewModel()
    {
        this.dbcontext = new MyContext(System.Configuration.ConfigurationManager.ConnectionStrings["MyContext"].ConnectionString);
        this.contentRepository = new Repository<Content>(dbcontext);
        this.feedbackRepository = new Repository<Feedback>(dbcontext);
        this.dbcontext.Configuration.LazyLoadingEnabled = true;

        //Retrieve a list of Screencasts
        Screencasts = contentRepository
            .Get(c => c.ContentTypeID == 1);

        //Retrieve a list of Podcasts
        Podcasts = contentRepository
            .Get(c => c.ContentTypeID == 2);

        //Retrieve a list of Documents
        Documents = contentRepository
            .Get(c => c.ContentTypeID == 3);

    }

    public MediaViewModel(int id)
    {
        this.dbcontext = new MyContext(System.Configuration.ConfigurationManager.ConnectionStrings["MyContext"].ConnectionString);
        this.contentRepository = new Repository<Content>(dbcontext);
        this.feedbackRepository = new Repository<Feedback>(dbcontext);
        this.dbcontext.Configuration.LazyLoadingEnabled = true;

        //Retrieve a list of Screencasts
        Screencasts = contentRepository
            .Get(c => c.ContentTypeID == 1);

        //Retrieve a list of Podcasts
        Podcasts = contentRepository
            .Get(c => c.ContentTypeID == 2);

        //Retrieve a list of Documents
        Documents = contentRepository
            .Get(c => c.ContentTypeID == 3);                       

        //Retrieve selected screencast
        SelectedMediaItem = contentRepository
            .Get(c => c.ContentID == id)
            .FirstOrDefault();              

    }

}

//获取
公共行动结果屏幕广播（int ID）
{                        
mvm=新的ViewModels.MediaViewModel（ID）；
返回视图（mvm）；
}
//职位
[HttpPost]
公共行动结果屏幕广播（MediaViewModel mvm）
{
反馈newFeedback=新反馈（）；
newFeedback.UserID=mvm.FeedbackComment.UserID；
newFeedback.ContentID=mvm.FeedbackComment.ContentID；
newFeedback.CourseID=null；
newFeedback.Timestamp=DateTime.Now；
newfeedbackstring=mvm.FeedbackComment.FeedbackString；
//初始化反馈存储库并保存更改
feedbackRepository=新存储库（dbcontext）；
feedbackRepository.Add（newFeedback）；
feedbackRepository.SaveChanges（）；
返回视图（mvm）；
}

当我在URL/Media/Screencast/1处调用页面开始时，它会加载一个viewmodel，其中填充了所选媒体的详细信息，所有内容都会按预期显示

当我尝试发回此页面时，我的viewmodel详细信息将丢失，尽管注释实际上已按预期保存，但我需要访问另一个页面并重新访问，然后才能看到

如何将@Html.BeginFor中的视图模型作为附加参数传递

我的ViewModel如下所示：

@{
ViewBag.Title = "Screencast";
Layout = "~/Views/Shared/_Layout.cshtml";
}
@model Project.ViewModels.MediaViewModel
<body onload="initialize()">

<div class="container region3wrap_screencast">
  <div class="row content_top_contact">
    <div class="nine columns">
      <ul class="breadcrumbs">
        <li><a href="@Url.Action("Index","Home")">Home</a></li>
        <li><a href="@Url.Action("Index","Media")">Media</a></li>
        <li><a href="@Url.Action("Screencast","Media")">Screencast</a></li>
        <li class="current"><a href="#">@Model.SelectedMediaItem.Name</a></li>
      </ul>
    </div>
  </div>
</div>

<div class="twelve columns leave-comment">
  <h3>Leave a Comment</h3>
  @using(Html.BeginForm("Screencast","Media", FormMethod.Post, Model))
  {              
    <div class="row">
      <div class="six columns">
        <div class="row">
          <div class="six columns">
            @Html.LabelFor(c => c.FeedbackComment.UserID)
            @Html.TextBoxFor(c => c.FeedbackComment.UserID)
          </div>
          <div class="six columns">
            @Html.LabelFor(c => c.FeedbackComment.ContentID)
            @Html.TextBoxFor(c => c.FeedbackComment.ContentID)
          </div>   
          <div class="row">
            <div class="twelve columns">
              @Html.LabelFor(c => c.FeedbackComment.FeedbackString)
              @Html.TextAreaFor(c => c.FeedbackComment.FeedbackString)
            </div>
          </div>        
        </div>
      </div>
    </div>          
    <input type="submit" value="Submit button" class="medium button bottom20"/>
  }
</div>
</body>

  //GET
  public ActionResult Screencast(int ID)
  {                        
    mvm = new ViewModels.MediaViewModel(ID);
    return View(mvm);
  }

  //POST
  [HttpPost]
  public ActionResult Screencast(MediaViewModel mvm)
  {
    Feedback newFeedback= new Feedback();
    newFeedback.UserID = mvm.FeedbackComment.UserID;
    newFeedback.ContentID = mvm.FeedbackComment.ContentID;
    newFeedback.CourseID = null;
    newFeedback.Timestamp = DateTime.Now;
    newFeedback.FeedbackString = mvm.FeedbackComment.FeedbackString;

    //Initialize the Feedback Repository and save changes
    feedbackRepository = new Repository<Feedback>(dbcontext);
    feedbackRepository.Add(newFeedback);
    feedbackRepository.SaveChanges();

    return View(mvm);
  }

public class MediaViewModel
{
    private Repository<Content> contentRepository;
    private Repository<Feedback> feedbackRepository;
    private MetaLearningContext dbcontext;

    public int screencastID { get; set; }

    public IEnumerable<Content> Screencasts { get; set; }
    public IEnumerable<Content> Podcasts { get; set; }
    public IEnumerable<Content> Documents { get; set; }
    public IEnumerable<Feedback> FeedbackComments { get; set; }
    public Content SelectedMediaItem { get; set; }
    public MetaLearningUser User { get; set; }
    public MetaLearningUser FeedbackAuthor { get; set; }
    public Feedback FeedbackComment { get; set; }

    public MediaViewModel()
    {
        this.dbcontext = new MyContext(System.Configuration.ConfigurationManager.ConnectionStrings["MyContext"].ConnectionString);
        this.contentRepository = new Repository<Content>(dbcontext);
        this.feedbackRepository = new Repository<Feedback>(dbcontext);
        this.dbcontext.Configuration.LazyLoadingEnabled = true;

        //Retrieve a list of Screencasts
        Screencasts = contentRepository
            .Get(c => c.ContentTypeID == 1);

        //Retrieve a list of Podcasts
        Podcasts = contentRepository
            .Get(c => c.ContentTypeID == 2);

        //Retrieve a list of Documents
        Documents = contentRepository
            .Get(c => c.ContentTypeID == 3);

    }

    public MediaViewModel(int id)
    {
        this.dbcontext = new MyContext(System.Configuration.ConfigurationManager.ConnectionStrings["MyContext"].ConnectionString);
        this.contentRepository = new Repository<Content>(dbcontext);
        this.feedbackRepository = new Repository<Feedback>(dbcontext);
        this.dbcontext.Configuration.LazyLoadingEnabled = true;

        //Retrieve a list of Screencasts
        Screencasts = contentRepository
            .Get(c => c.ContentTypeID == 1);

        //Retrieve a list of Podcasts
        Podcasts = contentRepository
            .Get(c => c.ContentTypeID == 2);

        //Retrieve a list of Documents
        Documents = contentRepository
            .Get(c => c.ContentTypeID == 3);                       

        //Retrieve selected screencast
        SelectedMediaItem = contentRepository
            .Get(c => c.ContentID == id)
            .FirstOrDefault();              

    }

}

公共类MediaViewModel
{
私有存储库内容存储库；
私有存储库反馈存储库；
私有MetaLearningContext-dbcontext；
public int screencastID{get；set；}
公共IEnumerable屏幕广播{get；set；}
公共IEnumerable播客{get；set；}
公共IEnumerable文档{get；set；}
公共IEnumerable反馈注释{get；set；}
公共内容SelectedMediaItem{get；set；}
公共MetaLearningUser用户{get；set；}
公共MetaLearningUser反馈作者{get；set；}
公共反馈意见{get；set；}
公共媒体视图模型（）
{
this.dbcontext=new MyContext（System.Configuration.ConfigurationManager.ConnectionString[“MyContext”].ConnectionString）；
this.contentRepository=新存储库（dbcontext）；
this.feedbackRepository=新存储库（dbcontext）；
this.dbcontext.Configuration.LazyLoadingEnabled=true；
//检索屏幕广播列表
Screencasts=contentRepository
.Get（c=>c.ContentTypeID==1）；
//检索播客列表
Podcasts=contentRepository
.Get（c=>c.ContentTypeID==2）；
//检索文档列表
文档=内容存储库
.Get（c=>c.ContentTypeID==3）；
}
公共媒体视图模型（int-id）
{
this.dbcontext=new MyContext（System.Configuration.ConfigurationManager.ConnectionString[“MyContext”].ConnectionString）；
this.contentRepository=新存储库（dbcontext）；
this.feedbackRepository=新存储库（dbcontext）；
this.dbcontext.Configuration.LazyLoadingEnabled=true；
//检索屏幕广播列表
Screencasts=contentRepository
.Get（c=>c.ContentTypeID==1）；
//检索播客列表
Podcasts=contentRepository
.Get（c=>c.ContentTypeID==2）；
//检索文档列表
文档=内容存储库
.Get（c=>c.ContentTypeID==3）；
//检索选定的屏幕广播
SelectedMediaItem=contentRepository
.Get（c=>c.ContentID==id）
.FirstOrDefault（）；
}
}

这可能是因为SelectedMediaItem没有与表单中的其他值一起发布。因此，当表单序列化为模型时，SelectedMediaItem属性为null。您可以做的只是在邮寄表单中添加以下内容：

@Html.HiddenFor(c => c.SelectedMediaItem)

@Html.HiddenFor(c => c.SelectedMediaItem)

只是想补充一下Mattias的答案：

1）他是对的——如果您想要一些信息重定向到何处，请将其放置在隐藏字段中或将其作为参数添加到表单方法中

2） MVC中常见的模式是PRG（Post/Redirect/Get），因此本质上，您的帖子应该用RedirectToAction（“Screencast”）而不是视图来回答。（）

要使用它，您应该稍微重构一下您的函数：

public ActionResult Screencast(int ID)
{                        
    mvm = new ViewModels.MediaViewModel(ID); //The id is in the viewmodel i think
    return View(mvm);
}


[HttpPost] 
//Even if unused include the formcollection for cases where the GET has the same signature
public ActionResult Screencast(int ID, MediaViewModel mvm, FormCollection collection)
{
    //Do something
    return RedirectToAction("Screencast", new { id = ID });
}

在你看来：

@using(Html.BeginForm("Screencast", new { id = Model.SelectedMediaItem })) 
{ ... }

可能建议的重载需要更多参数，但您将看到

只是想补充一下Mattias的答案：

1）他是对的