两段相同的代码工作方式不同

本文关键字：代码 工作 方式不 两段 | 更新日期: 2023-09-27 17:57:25

在我的项目中，我遇到了一个问题：EF没有从连接表加载数据，但在其他几乎相同的代码中，一切都是完美的。有人能解释一下吗？

情况如下：

一切正常，已加载type.name：

[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult pacientEdit([Bind(Include = "ID,comments")] Anamnesis anamnesis)
{
    if (ModelState.IsValid)
    {
        db.Entry(anamnesis).State = EntityState.Modified;
        db.SaveChanges();
        return pacientDetails(anamnesis.ID);
    }
    return PartialView(anamnesis);
}
public ActionResult pacientDetails(int? id)
{
    if (id == null)
    {
        return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
    }
    Anamnesis anamnesis = db.anamneses.Include(p => p.type).Where(p => p.ID == id).First();
    if (anamnesis == null)
    {
        return HttpNotFound();
    }
    return PartialView("~/views/Anamnesis/pacientDetails.cshtml", anamnesis);
}

在这里，我运行PacientEdit，然后它流到PacientDetails并给我完整的记忆，包括完整的类型及其名称。

All is bad，type.name is null：

在第二种情况下，类型的名称为null，尽管我试图从数据库加载它。

[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult pacientEdit(Assigment assigment)
{
    if (ModelState.IsValid)
    {
        db.Entry(assigment).State = EntityState.Modified;
        db.SaveChanges();
        return pacientDetails(assigment.ID);
        //dirty fix, but works: return (new AssigmentsController()).pacientDetails(assigment.ID);
    }
    return PartialView(assigment);
}
public ActionResult pacientDetails(int? id)
{
    if (id == null)
    {
        return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
    }
    Assigment assigment = db.assigments.Include(p => p.type).Where(p => p.ID == id).First();
    if (assigment == null)
    {
        return HttpNotFound();
    }
    return PartialView("~/views/Assigments/pacientDetails.cshtml", assigment);
}

在这种情况下，pacientDetails中的所有数据（包括type_ID）都在加载，但type.name为null

有人能解释这种行为吗？

使用型号：

public class Anamnesis
{
    public int ID { get; set; }
    public AnamnesisEventType type { get; set; }
    public String comments { get; set; }
}
public class Assigment
{
    public int ID { get; set; }    
    public AssigmentType type { get; set; }    
    public decimal? weight { get; set; }
    public decimal? dose { get; set; }
    public decimal? inADay { get; set; }
    [DataType(DataType.MultilineText)]
    public String comments { get; set; }
    public String medicine { get; set; }
    [DefaultValue(1)]
    public int actual { get; set; }
    public DateTime cancelDate { get; set; }

}
public class AnamnesisEventType
{
    public int ID { get; set; }
    public String name { get; set; }
}
public class AssigmentType
{
    public int ID { get; set; }
    public String name { get; set; }
    public String description { get; set; }
}

这是用于AssegmentsController的pacientEdit的视图：

@model WebApplication2.Models.Assigment
<form id="@String.Format("AssigmentsEdit{0}", Model.ID)">
    @Html.AntiForgeryToken()
    @Html.HiddenFor(model => model.ID)
    @Html.HiddenFor(model => model.type.ID)
    @Html.HiddenFor(model => model.cancelDate)
    @Html.HiddenFor(model => model.actual)
    <div class="row">
        <div class="col-md-4">
            <strong>
                @Html.DisplayFor(model => model.type.name)
            </strong>
        </div>
        <div class="col-md-6">
            <p>
                @Html.EditorFor(model => model.medicine, new { htmlAttributes = new { @class = "form-control", @placeholder = Html.DisplayNameFor(model => model.medicine) } })
            </p>
        </div>
        <div class="col-md-2">
            <a onclick="CancelEdit('Assigments', @Model.ID);" class="btn btn-warning btn-sm"><span class="glyphicon glyphicon-backward" aria-hidden="true"></span></a>
            <a class="btn btn-sm btn-primary" onclick="PostEditForm('Assigments', @Model.ID);">
                <span class="glyphicon glyphicon-save" aria-hidden="true"></span>
            </a>
        </div>
    </div>
    <div class="row alert alert-info" style="margin-top:10px">
        <div class="col-md-4">
            <h4><span class="glyphicon glyphicon-tint" aria-hidden="true"></span> Назначение:</h4>
             @Html.EditorFor(model => model.weight, new { htmlAttributes = new { @class = "form-control", @placeholder = Html.DisplayNameFor(model => model.weight) } })
            @Html.EditorFor(model => model.dose, new { htmlAttributes = new { @class = "form-control", @placeholder = Html.DisplayNameFor(model => model.dose) } }) 
            @Html.EditorFor(model => model.inADay, new { htmlAttributes = new { @class = "form-control", @placeholder = Html.DisplayNameFor(model => model.inADay) } })
        </div>
        <div class="col-md-8">
            <h4><span class="glyphicon glyphicon-comment" aria-hidden="true"></span> @Html.DisplayNameFor(model => model.comments):</h4>
            <p>@Html.EditorFor(model => model.comments, new { htmlAttributes = new { @class = "form-control", @placeholder = Html.DisplayNameFor(model => model.comments) } })</p>
        </div>

    </div>
    </form>
        <hr />

两段相同的代码工作方式不同

我想问题在于您试图使用相同的名称绑定Assignment ID和AssignmentType ID。创建一个AssignmentViewModel类（这是一个很好的实践），其中只有成员"type"的ID，如下所示：

public class AssigmentViewModel
{
    public int ID { get; set; }    
    public int TypeId { get; set; }    
    public decimal? weight { get; set; }
    public decimal? dose { get; set; }
    public decimal? inADay { get; set; }
    [DataType(DataType.MultilineText)]
    public String comments { get; set; }
    public String medicine { get; set; }
    public int actual { get; set; }
    public DateTime cancelDate { get; set; }
}

你也可以尝试修改隐藏类型如下：

@Html.HiddenFor(model => model.type)

希望这能帮助

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