我的历史记录页面运行正常，但是现在当我尝试添加历史记录时，它并没有创建，并且给了我NullReferenceException: Object reference not set to an instance of an object.
此行错误：
<h2>Canidate - @Model.Name</h2>
这是我的控制人：
public IActionResult CandidateHistory(int Id)
{
using (var applicationcontext = new ApplicationContext())
{
var candidate = applicationcontext.Candidates.Where(s => s.Id.Equals(Id)).SingleOrDefault();
if (candidate == null)
{
return NotFound();
}
return View(candidate);
}
}
[HttpPost, ActionName("CandidateHistory")]
[ValidateAntiForgeryToken]
public IActionResult CandidateHistoryPost([Bind("Description, State, DateOfDescription, Saving, Interviewer, Feedback, FeedbackDate, Behavior,InterViewDate")]Candidate candidate, int Id)
{
try
{
using (var applicationContext = new ApplicationContext())
{
var candidates = applicationContext.Candidates.Where(s => s.Id.Equals(Id)).SingleOrDefault(); //Getting all the DATA from the Candidate with the Id passed in the Get Method
candidates.DescriptionList.Add(candidate);
applicationContext.Candidates.Add(candidates);
applicationContext.SaveChanges();
return RedirectToAction("CandidateHistory");
}
}
catch (DbUpdateException ex)
{
//Log the error (uncomment ex variable name and write a log.
ModelState.AddModelError("", "Unable to save changes. " + "Try again, and if the problem persists " + "see your system administrator.");
}
return View();
}
我真的不知道为什么这会给我这个错误。
这也是我的观点：
@model HCCBPOHR.Data.Candidate
@{
ViewData["State"] = "CandidateHistory";
}
<h2>Canidate - @Model.Name</h2>
<label>History</label>
<hr />
<div class="panel panel-default">
<div class="panel-heading">
<i class="fa fa-clock-o fa-fw"></i> History Of @Model.Name
</div>
<div class="panel-body">
@foreach (var Description in Model.DescriptionList)
{
@if (Description.Saving == true)
{
<ul class="timeline">
<li class="timeline">
<div class="timeline-badge">
<i class="fa fa-check"></i>
</div>
<div class="timeline-panel">
<div class="timeline-heading">
<h4 class="timeline-title">@Description.State</h4>
<p>
<small class="text-muted"><i class="fa fa-clock-o"></i> @Description.DateOfDescription.ToShortDateString()</small>
</p>
</div>
<div class="timeline-body">
<p><b>Description:</b> @Description.Description</p>
</div>
<div class="timeline-body">
<p><b>Interviewer:</b> @Description.Interviewer</p>
</div>
<div class="timeline-body">
<p><b>Feedback:</b> @Description.Feedback</p>
</div>
<div class="timeline-body">
<p><b>FeedbackDate:</b> @Description.FeedbackDate</p>
</div>
<div class="timeline-body">
<p> <b>Bad behavior:</b> @Description.Behavior</p>
</div>
<div class="timeline-body">
<p> <b>Applied For:</b> @Description.SelectedAd</p>
</div>
</div>
</li>
</ul>
}
@if (Description.Saving == false)
{
<ul class="timeline">
<li class="timeline-inverted">
<div class="timeline-badge">
<i class="fa fa-check"></i>
</div>
<div class="timeline-panel">
<div class="timeline-heading">
<h4 class="timeline-title">@Description.State</h4>
<p>
<small class="text-muted"><i class="fa fa-clock-o"></i> @Description.DateOfDescription.ToShortDateString()</small>
</p>
</div>
<div class="timeline-body">
<p><b>Description:</b> @Description.Description</p>
</div>
<div class="timeline-body">
<p><b>Interviewer:</b> @Description.Interviewer</p>
</div>
<div class="timeline-body">
<p><b>Feedback:</b> @Description.Feedback</p>
</div>
<div class="timeline-body">
<p><b>FeedbackDate:</b> @Description.FeedbackDate</p>
</div>
<div class="timeline-body">
<p> <b>Bad behavior:</b> @Description.Behavior</p>
</div>
<div class="timeline-body">
<p> <b>Bad behavior:</b> @Description.InterViewDate</p>
</div>
</div>
</li>
</ul>
}
}
</div>
</div>
<button type="button" class="btn btn-primary" data-toggle="modal" data-target="#exampleModal" data-whatever="@Model.Saving"> Add History Description</button>
<div class="modal fade" id="exampleModal" tabindex="-1" role="dialog" aria-labelledby="exampleModalLabel" aria-hidden="true">
<div class="modal-dialog" role="document">
<div class="modal-content">
<div class="modal-body">
<form asp-action="CandidateHistory">
<div asp-validation-summary="ModelOnly" class="text-danger">
</div>
<div class="form-group">
<label>Estado</label>
<select asp-for="State" class="form-control">
<option value="FirstIntrerview">First Interview
</option>
<option value="SecoundInterview">Secound Interview</option>
<option value="Contract">Contract</option>
</select>
</div>
<div class="form-group">
<label asp-for="InterViewDate" class="control-label">Interview Date:</label>
<input asp-for="InterViewDate" class="form-control" value="" />
<span asp-validation-for="InterViewDate" class="text-danger"></span>
</div>
<div class="form-group">
<label asp-for="Description" class="control-label">Description</label>
<input asp-for="Description" class="form-control" value="" />
<span asp-validation-for="Description" class="text-danger"></span>
</div>
<div class="form-group">
<label>Side of History</label>
<select asp-for="Saving" class="form-control">
<option value="false">Candidate </option>
<option value="true">Hitachi</option>
</select>
</div>
<div class="form-group">
<label>Interviewer</label>
<select asp-for="Interviewer" class="form-control">
<option value="Mananger">Mananger </option>
<option value="Diretora">Diretora</option>
</select>
</div>
<div class="form-group">
<label>FeedBack</label>
<select asp-for="Feedback" class="form-control">
<option value="Yes">Yes </option>
<option value="No">No</option>
</select>
</div>
<div class="form-group">
<label asp-for="FeedbackDate" class="control-label">Feedback Date:</label>
<input asp-for="FeedbackDate" class="form-control" value="" />
<span asp-validation-for="FeedbackDate" class="text-danger"></span>
</div>
<div class="form-group">
<label>Bad Behavior?</label>
<select asp-for="Behavior" class="form-control">
<option value="Yes">Yes </option>
<option value="No">No</option>
</select>
</div>
<div class="form-group">
<label asp-for="DateOfDescription" class="form-group">Date of the HistoryPost</label>
<input asp-for="DateOfDescription" class="form-group" />
<span asp-validation-for="DateOfDescription" class="text-danger"></span>
</div>
<div class="form-group">
<input type="submit" value="Create" class="btn btn-default" />
</div>
</form>
</div>
<div class="modal-footer">
<button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
</div>
</div>
</div>
</div>