Question

我得到的是一般错误： -

其他信息：附加“实体”类型的实体失败因为同一类型的另一个实体已经具有相同的主要实体核心价值。使用“附加”方法或设置时可能会发生这种情况如果有任何实体，则实体的状态为“未更改”或“已修改” 图表具有冲突的键值。这可能是因为一些实体是新的，尚未收到数据库生成的密钥值。在这种情况下，使用“添加”方法或“已添加”实体状态跟踪图形，然后将非新实体的状态设置为 “不变”或“适当修改”

当实体试图改变其状态时，它正在线下发生。

public void InsertOrUpdate(T entity)
    {
        if (entity.Id == default(int))
        {
            entity.Created = DateTime.Now;
            entity.LastEdit = DateTime.Now;

            Context.Initial.Add(initial);
        }
        else
        {
            entity.LastEdit = DateTime.Now;
            Context.Entry(entity).State = System.Data.Entity.EntityState.Modified;
        }
    }

但是，当我

时，我会得到它

重新加载上下文，即从视图初始化存储库。
正确使用附件Context.T.Attach(entity)

当我不更改状态信息或使用附件时，它不会更新任何内容。

这是我的控制器代码

[HttpPost]
[Authorize]
public ActionResult Create(NewViewModel viewModel)
{
   if (ModelState.IsValid)
   {
      m_CTS.InsertOrUpdate(viewModel.entity);
      m_CTS.Save();

      // My big problem is that the Primary key that 
      // was generated doesnt come back from the view 
      // once edited, so I have created a property in 
      // the viewmodel to handle this

      viewModel.ID = viewModel.entity.Id;

      return RedirectToAction("Edit", new { id = viewModel.entity.Id });
    }
    else
    {
      return View("New", viewModel);
    }
}

[HttpGet]
[Authorize]
public ViewResult Edit(int id)
{
  // Getting this from the same context of when it was created
  viewModel.entity = respoitory.Find(id);

  return View(viewModel);
}

[HttpPost]
[Authorize]
public ActionResult Edit(NewViewModel viewModel)
{
   // Could be the problem : As I said above the ID on the entity.id 
   // never comes back from the view (because I am using a viewmodel?) 
   // So I need to assign the ViewModel ID to the entity model id 
   // before I try and update it

   viewModel.entity.Id = viewModel.ID;

   m_CTS.InsertOrUpdate(viewModel.entity);
   m_CTS.Save();

   return RedirectToAction("Edit", new { id = viewModel.entity.Id });
}

我是否有上述代码出现此错误的原因？

由于

Answer 1

您已在代码的注释中发现了问题：

       // My big problem is that the Primary key that 
       // was generated doesnt come back from the view 
       // once edited, so I have created a property in the viewmodel to handle this

要解决此问题，请在视图中添加@Html.HiddenFor(m => m.Id)。现在，当您向控制器发送POST时，您的视图模型参数将包含您首先发送到视图的Id字段。

实体框架更新实体错误

1 个答案: