ASP.NET MVC5:想要使用模型绑定更新Collection中的多个项目

Question

所以我有一个User对象集合,它应该是可批量编辑的(同时编辑许多用户).我正在使用Entity Framework将用户输入保存到数据库.

控制器方法从表单获取的集合为null.为什么？另外,BindAttribute是否可以与我的代码中的集合一起使用？

视图:

@model IEnumerable<Domain.User>
@using (Html.BeginForm("UpdateUsers", "Users"))
{
    @Html.AntiForgeryToken()
    @Html.ValidationSummary(true)
    foreach (var item in Model)
    {
        @Html.HiddenFor(modelItem => item.Id)
        @Html.EditorFor(modelItem => item.FirstName)
        @Html.ValidationMessageFor(model => item.FirstName)
        @Html.EditorFor(modelItem => item.LastName)
        @Html.ValidationMessageFor(model => item.LastName)
        @Html.EditorFor(modelItem => item.Birth)
        @Html.ValidationMessageFor(model => item.Birth)
    }

    <input type="submit" value="Update user data"/>
}

控制器:

[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult UpdateUsers([Bind(Include = "Id,FirstName,LastName,Birth")] IEnumerable<User> users)
{
    if (ModelState.IsValid)
    {
        foreach (User u in users)
        {
            db.Entry(u).State = EntityState.Modified;
        }
        db.SaveChanges();
    }

    return RedirectToAction("EditUsers");
}

Answer 1

你需要使用一个for而不是foreach按顺序索引你的集合,以便ModelBinder选择它:

for (var i = 0 ; i < Model.Count(); i++)
    {
        @Html.HiddenFor(modelItem => modelItem[i].Id)
        @Html.EditorFor(modelItem => modelItem[i].FirstName)
        @Html.ValidationMessageFor(modelItem => modelItem[i].FirstName)
        @Html.EditorFor(modelItem => modelItem[i].LastName)
        @Html.ValidationMessageFor(modelItem => modelItem[i].LastName)
        @Html.EditorFor(modelItem => modelItem[i].Birth)
        @Html.ValidationMessageFor(modelItem => modelItem[i].Birth)
    }