生成视图出错

Question

以下代码有什么问题？它是由添加视图向导生成的。当我导航到控制器时，我收到以下错误：String was not recognised as a valid Boolean 并突出显示以下行：@using (Html.BeginForm())

这里是视图：

  @model Radio_Management_Interface.DomainModel.Entities.Network

@{
    ViewBag.Title = "Create";
    Layout = "~/Views/Shared/_Layout_main.cshtml";
}

<h2>Create</h2>


@using (Html.BeginForm()) 
{
    @Html.AntiForgeryToken()

    <div class="form-horizontal">
        <h4>Network</h4>
        <hr />
        @Html.ValidationSummary(true)

        <div class="form-group">
            @Html.LabelFor(model => model.name, new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.name)
                @Html.ValidationMessageFor(model => model.name)
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.startCode, new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.startCode)
                @Html.ValidationMessageFor(model => model.startCode)
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.frequency, new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.frequency)
                @Html.ValidationMessageFor(model => model.frequency)
            </div>
        </div>

        <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <input type="submit" value="Create" class="btn btn-default" />
            </div>
        </div>
    </div>
}

<div>
    @Html.ActionLink("Back to List", "Index")
</div>

@section Scripts {
    @Scripts.Render("~/bundles/jqueryval")
}`

控制器：

//
    // GET: /Networks/Details/5
    public ActionResult Details(int? id)
    {
        if (id == null)
        {
            return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
        }
        Network network = db.Networks.Find(id);
        if (network == null)
        {
            return HttpNotFound();
        }
        return View(network);
    }

领域模型：

   public class Network
{
    public int networkID { get; set; }
    public string name { get; set; }
    public int startCode { get; set; }
    public decimal frequency { get; set; }
    public virtual List<Block> blocks { get; set; }
}

Answer 1

你的 id 是一个可以为空的类型，用这一行代替它：

  Network network = db.Networks.Find(id.Value);

还有这个：

 if (id == null)

可以改成这样：

 if (!id.HasValue)

问题出在以下行：

Network network = db.Networks.Find(id);

id 实际上是一个可以为空的类型，当它期望值时传递给您的 Find 方法。

对于可为空的类型，您可以使用 Value 属性读取基础值，即

id.Value