我遇到了一个问题，我认为我已经正确设置了，但结果总是没有。
以下是三种模式：
public class FamilyMember
{
[Key]
public int id { get; set; }
[Required]
[Display(Name = "First Name")]
public string firstName { get; set; }
[Required]
[Display(Name = "Surname")]
public string surname { get; set; }
[Required]
[Display(Name = "Date of Birth")]
public DateTime dob { get; set; }
public virtual FamilyRelationship FamilyRelationship { get; set; }
[Display(Name = "Full Name")]
public string fullName
{
get
{
return string.Format("{0} {1}", firstName, surname);
}
}
}
public class RelationshipType
{
[Key]
public int id { get; set; }
[Required]
[Display(Name="Relationship Type")]
public string relationshipType { get; set; }
public virtual FamilyRelationship FamilyRelationship { get; set; }
}
public class FamilyRelationship
{
[Key]
public int id { get; set; }
[ForeignKey("FamilyMembers")]
[Display(Name = "First Family Member")]
public int familyMemberPrimary { get; set; }
[ForeignKey("FamilyMembers")]
[Display(Name = "Second Family Member")]
public int familyMemberSecondary { get; set; }
[Display(Name = "Relationship Type")]
public int relationshipType { get; set; }
public virtual ICollection<FamilyMember> FamilyMembers { get; set; }
public virtual ICollection<RelationshipType> RelationshipTypes { get; set; }
}
因此，我已成功将数据添加到FamilyMember和RelationshipType，并且CRUD运行正常。
问题出现在FamilyRelationship的创建控制器/视图中。下拉列表工作正常，并在两个相关菜单中显示家庭成员，并且关系也显示在relationType下拉列表中。但是，当我单击create时，所有值都设置为null。
创建控制器：
// GET: FamilyRelationships/Create
public ActionResult Create()
{
ViewBag.familyMember = new SelectList(db.FamilyMembers, "id", "fullName");
ViewBag.relationship = new SelectList(db.RelationshipTypes, "id", "relationshipType");
return View();
}
// POST: FamilyRelationships/Create
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create([Bind(Include = "id,familyMemberPrimary,familyMemberSecondary,relationshipType")] FamilyRelationship familyRelationship)
{
if (ModelState.IsValid)
{
db.FamilyRelationships.Add(familyRelationship);
db.SaveChanges();
return RedirectToAction("Index");
}
return View(familyRelationship);
}
创建视图：
@model FamilyTree.Models.FamilyRelationship
@{
ViewBag.Title = "Create";
}
<h2>Create</h2>
@using (Html.BeginForm())
{
@Html.AntiForgeryToken()
<div class="form-horizontal">
<h4>FamilyRelationship</h4>
<hr />
@Html.ValidationSummary(true, "", new { @class = "text-danger" })
<div class="form-group">
@Html.LabelFor(model => model.familyMemberPrimary, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@*@Html.EditorFor(model => model.familyMemberPrimary, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.familyMemberPrimary, "", new { @class = "text-danger" })*@
@Html.DropDownList("familyMember", null, htmlAttributes: new { @class = "form-control" })
@Html.ValidationMessageFor(model => model.familyMemberPrimary, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.familyMemberSecondary, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.DropDownList("familyMember", null, htmlAttributes: new { @class = "form-control" })
@Html.ValidationMessageFor(model => model.familyMemberPrimary, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.relationshipType, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.DropDownList("relationship", null, htmlAttributes: new { @class = "form-control" })
@Html.ValidationMessageFor(model => model.relationshipType, "", new { @class = "text-danger" })
</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")
}
请让我知道我哪里出错了，如果可能的话，请提供一个示例来完成这项工作。
答案 0 :(得分：2)
private void Flush() {
using (DataContext db = new DataContext() {
foreach(Log l in _logs) {
db.Logs.Add(new LogObject() { propX = "blabla" });
}
db.SaveChanges(); // save #2
}
}
您需要使用最有可能的实际属性名称
@Html.DropDownList("familyMember"
您还必须重命名viewbag属性以匹配要显示的项目..或使用dropdownlistfor
@Html.DropDownList("familyMemberPrimary"您还需要为familyMemberSecondary
添加下拉列表@Html.DropDownListFor(a => a.familyMemberPrimary, (SelectList)ViewBag.familyMember , new { @class = "form-control" })
这应该让你非常接近......
@Html.DropDownListFor(a => a.familyMemberSecondary, (SelectList)ViewBag.familyMember , new { @class = "form-control" })
确保在POST失败后重新设置ViewBag属性
答案 1 :(得分：1)
这是预期的行为。记住Http是无国籍的。因此，您需要在返回视图之前重新加载下拉数据
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create([Bind(Include = "id,familyMemberPrimary,familyMemberSecondary,
relationshipType")] FamilyRelationship familyRelationship)
{
if (ModelState.IsValid)
{
db.FamilyRelationships.Add(familyRelationship);
db.SaveChanges();
return RedirectToAction("Index");
}
//Let's reload the data for dropdown.
ViewBag.familyMember = new SelectList(db.FamilyMembers, "id", "fullName");
ViewBag.relationship = new SelectList(db.RelationshipTypes, "id", "relationshipType");
return View(familyRelationship);
}
编辑： 根据评论
FamilyRelationship中的值如此familyMemberPrimary， familyMemberSecondary和relationshipType的值为0，其中I 我希望每个人的身份都会被遗漏。
因为您在视图中使用EditorFor辅助方法来处理familyMemberPrimary属性。因此，如果您没有在该输入字段中填充值，则它将具有默认值（对于int类型为0）
如果您希望使用下拉列表选择（家庭成员）填充该属性，则应将下拉列表名称设为familyMemberPrimary，以便在发布表单时，模型绑定将设置所选的选项值to familyMemberPrimary property。
@Html.DropDownList("familyMemberPrimary",
ViewBag.familyMember as IEnumerable<SelectListItem>,
htmlAttributes: new { @class = "form-control" })