如果我有一个网站,我可以在其中创建以下模型中定义的实体:
public partial class Component
{
public int Id { get; set; }
public string Name { get; set; }
public string Info { get; set; }
public string ManufacturerLink { get; set; }
public string Datasheet { get; set; }
}
现在,我希望能够从我的网站编辑这个实体,我认为我按顺序完成了大部分实体,因为我能够编辑我想要的字段(除Id之外的所有字段)。 / p>
我的问题是,当我尝试对其进行更改时,Id将设置为0,这将始终只使用Id 0更新数据库表中的行。如何从我想要的实体中保留Id改变?
这是我的编辑视图:
@using (Html.BeginForm("Edit", "Edit", FormMethod.Post, new {enctype = "multipart/form-data"}))
{
@Html.AntiForgeryToken()
<div class="form-horizontal">
<h4>Component</h4>
<hr />
@Html.ValidationSummary(true, "", new { @class = "text-danger" })
<div class="form-group">
@Html.LabelFor(model => model.Name, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.Name, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.Name, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.Info, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.Info, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.Info, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.Image, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@{
var base64 = Convert.ToBase64String(Model.Image);
var imgSrc = String.Format("data:image/gif;base64,{0}", base64);
}
<img src="@imgSrc" height="300px" width="300px" alt="No image to display." />
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.ManufacturerLink, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.ManufacturerLink, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.ManufacturerLink, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.Datasheet, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.Datasheet, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.Datasheet, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
<div class="col-md-offset-2 col-md-10">
<input type="submit" value="Save changes" class="btn btn-primary" />
</div>
</div>
</div>
}
这是我在控制器中的操作方法,单击“保存更改”输入按钮时会调用该方法:
[HttpPost]
public ActionResult Edit(Component component)
{
if (ModelState.IsValid)
{
componentRepository.UpdateComponent(component);
return RedirectToAction("Index", component.Id);
}
return View("Index", component);
}
这是来自存储库的UpdateComponent:
public void UpdateComponent(Component component)
{
Component comp = mContext.Components.Find(component.Id);
if (comp != null)
{
comp.Name = component.Name;
comp.Info = component.Info;
comp.Datasheet = component.Datasheet;
comp.ManufacturerLink = component.ManufacturerLink;
}
mContext.SaveChanges();
}
答案 0 :(得分:4)
您发布的表单中应该有一个隐藏字段,其中包含Id的值。
@Html.HiddenFor(model=> model.Id)
您可以将其放在里面您发布的表单中。
为什么会这样?
当您发布表单并且模型数据绑定的时间到来时,由于您为Id
发布的表单中没有任何值,Id
会将其视为{&#39}。 s默认值,即0。