使用 html.hiddenfor 时，表单集合优先于模型

Question

我知道 asp.net mvc web 应用程序中的 html 助手，例如 Html.EditorFor Html.TextBoxFor 等会查看表单集合，如果找不到值，它将使用模型值，除非调用 @987654321 @ 但现在我有以下后期编辑操作方法，我正在检查并发异常：-

[HttpPost]
[ValidateAntiForgeryToken]
public async Task<ActionResult> Edit(Skill skill)
{
  try
  {
    var dbskill = db.Skills.SingleOrDefault(a => a.SkillID == skill.SkillID);
    db.Entry(dbskill).State = EntityState.Detached;
    skill.Created = dbskill.Created;
    skill.Modified = System.DateTime.Now;
    skill.CreatedBy = dbskill.CreatedBy;
    skill.ModifiedBy = staffrepo.GetUserIdByUserName(User.Identity.Name.Substring(User.Identity.Name.IndexOf("\\") + 1));
    skill.DeletedDate = dbskill.DeletedDate;
    skill.IsActive = dbskill.IsActive;
    skill.StatusID = db.SkillStatus.Where(a => a.SkillStatusName.ToLower().StartsWith("pen")).SingleOrDefault().SkillStatusID;
    if (ModelState.IsValid)
    {
      skill.CurrentVersion =  dbskill.CurrentVersion + (Decimal)0.01;
      db.Entry(skill).State = EntityState.Modified;
      await db.SaveChangesAsync();
      return RedirectToAction("Details", new { id =skill.SkillID});
    }
  }        
  catch (DbUpdateConcurrencyException ex)
  {
    var entry = ex.Entries.Single();
    var clientValues = (Skill)entry.Entity;
    var databaseEntry = entry.GetDatabaseValues();
    var databaseValues = (Skill)databaseEntry.ToObject();
    var currentSkillTypename = db.SkillTypes.SingleOrDefault(a => a.SkillTypeID == databaseValues.SkillTypeID).Name;
    var currentSkillStatusname = db.SkillStatus.SingleOrDefault(a => a.SkillStatusID == databaseValues.StatusID).SkillStatusName;
    var currentModifiedByName = db.Staffs.SingleOrDefault(a => a.StaffID == databaseValues.ModifiedBy).SamAccUserName;
    if (databaseEntry == null)
    {
      ModelState.AddModelError(string.Empty, "Unable to save changes. The department was deleted by another user.");
    }
    else
    {              
      if (databaseValues.Name != clientValues.Name)
        ModelState.AddModelError("Name", "Current value: " + databaseValues.Name);

      //code goes here...........
      ModelState.AddModelError(string.Empty, "The record you attempted to edit "
      + "was modified by another user after you got the original value. The "
      + "edit operation was canceled and the current values in the database "
      + "have been displayed. If you still want to edit this record, click "
      + "the Save button again. Otherwise click the Back to List hyperlink.");
      skill.timestamp = databaseValues.timestamp;
    }
  }
  catch (Exception e)
  {
    var c = e;
  }
  //
  return View(skill);
}

我感到困惑的是在异常中使用它：-

 skill.timestamp = databaseValues.timestamp

现在，由于我在视图上使用 hiddenfor 将时间戳传递给后期编辑操作方法，因此这意味着 Skill.timestamp 将始终相同，用户将始终收到并发异常，因为 Html. Hiddenfor 将始终从模型中读取值，因此时间戳将始终相同，但发生的情况是在第一次并发异常之后，并且如果用户单击保存，那么第二次他的修改将被保存。 ..那么有人可以就此提出建议吗？

Answer 1

默认情况下，值提供者集合按以下顺序评估来自各种来源的值：

• 之前绑定的动作参数，当动作是子动作时

• 表单字段（Request.Form）

• JSON 请求正文 (Request.InputStream) 中的属性值， 但仅当请求是 AJAX 请求时

• 路线数据（RouteData.Values）

• 查询字符串参数（Request.QueryString）

• 发布的文件（Request.Files）

https://msdn.microsoft.com/en-us/magazine/hh781022.aspx

http://dotnetslackers.com/articles/aspnet/Understanding-ASP-NET-MVC-Model-Binding.aspx