Asp.net mvc 如何发送多值以创建操作

我有一个医生，我想将医生子专业添加到医生子专业表多对多关系中

我需要从multiselect列表中添加子专业，但我的控制器只添加第一个选择，我希望我的创建控制器获取所有传递的子专业并创建它

我的模型

public partial class DoctorSubSpecialty
{
    public int Id { get; set; }
    public Nullable<int> DoctorId { get; set; }
    public Nullable<int> SubSpecialtyId { get; set; }

    public virtual DoctorProfile DoctorProfile { get; set; }
    public virtual  SubSpecialty SubSpecialty { get; set; }
}

创建后期操作

 [HttpPost]
    [ValidateAntiForgeryToken]
    public async Task<ActionResult> Create([Bind(Include = "Id,DoctorId,SubSpecialtyId")] DoctorSubSpecialty doctorSubSpecialty)
    {

            DoctorSubSpecialty doctorSub = db.DoctorSubSpecialties.Where(d => d.DoctorId == doctorSubSpecialty.DoctorId & d.SubSpecialtyId == doctorSubSpecialty.SubSpecialtyId).FirstOrDefault();
            if (doctorSub == null) { 
            db.DoctorSubSpecialties.Add(doctorSubSpecialty);
            await db.SaveChangesAsync();
            }

{ @Html.AntiForgeryToken（）

博士专科

@Html.ValidationSummary（true，“，new{@class=“text danger”}）
@LabelFor（model=>model.DoctorId，“DoctorId”，htmlAttributes:new{@class=“control label col-md-2”，@id=“DoctorId”}）
@DropDownList（“DoctorId”，null，htmlAttributes:new{@class=“form control”}）
@Html.ValidationMessageFor（model=>model.DoctorId，“，new{@class=“text danger”}）
@LabelFor（model=>model.SubSpecialtyId，“SubSpecialtyId”，htmlAttributes:new{@class=“controllabel col-md-2”}）
@DropDownList（“SubSpecialtyId”，（MultiSelectList）ViewBag.SubSpecialtyId，htmlAttributes:new{@multiple=“multiple”，@class=“form control”}）
@Html.ValidationMessageFor（model=>model.SubSpecialtyId，“，new{@class=“text danger”}）

---

}

创建一个特定于您的用例的视图模型，该视图模型实际上可以传输多个Id。 也就是说，您需要一个

int[]

来绑定所选内容。 ViewModel还可以帮助您摆脱所有这些

ViewBag

和

[Bind]

废话

public class CreateDoctorSubSpecialtyViewModel {

     // These are the selected values to be posted back
     public int DoctorId { get; set; }
     public int[] SubSpecialtyIds { get; set; }

     // These are the possible values for the dropdowns
     public IEnumerable<SelectListItem> DoctorProfiles { get; set; }
     public IEnumerable<SelectListItem> SubSpecialties { get; set; }
}

查看“Create.cshtml”（为了清晰起见，样式设置已删除）-告诉MVC我们要在

@model

中使用哪个ViewModel：

@model CreateDoctorSubSpecialtyViewModel
@using (Html.BeginForm("Create", "YourControllerName", FormMethod.Post)) {

    @Html.DropDownListFor(m => m.DoctorId, Model.DoctorProfiles)

    @Html.DropDownListFor(m => m.SubSpecialtyIds, Model.SubSpecialties, new { multiple = "multiple" })

    <input type="submit" />
}

---

EDIT

@Html。DropDownListFor

需要一个

IEnumerable

作为第二个参数

<div class="form-horizontal">
    <h4>DoctorSubSpecialty</h4>
    <hr />
    @Html.ValidationSummary(true, "", new { @class = "text-danger" })
    <div class="form-group">
        @Html.LabelFor(model => model.DoctorId, "DoctorId", htmlAttributes: new { @class = "control-label col-md-2", @id = "DoctorID" })
        <div class="col-md-10">
            @Html.DropDownList("DoctorId", null, htmlAttributes: new { @class = "form-control" })
            @Html.ValidationMessageFor(model => model.DoctorId, "", new { @class = "text-danger" })
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.SubSpecialtyId, "SubSpecialtyId", htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.DropDownList("SubSpecialtyId",(MultiSelectList)ViewBag.SubSpecialtyId, htmlAttributes: new { @multiple = "multiple", @class = "form-control" })
            @Html.ValidationMessageFor(model => model.SubSpecialtyId, "", 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>

public class CreateDoctorSubSpecialtyViewModel {

     // These are the selected values to be posted back
     public int DoctorId { get; set; }
     public int[] SubSpecialtyIds { get; set; }

     // These are the possible values for the dropdowns
     public IEnumerable<SelectListItem> DoctorProfiles { get; set; }
     public IEnumerable<SelectListItem> SubSpecialties { get; set; }
}

[HttpGet]
public ActionResult Create() {

    var doctorProfiles = db.DoctorProfiles.Select(d => 
        new SelectListItem {
            Text = d.FullName,
            Value = d.Id
        }
    ).ToArray();

    var subSpecialties = db.SubSpecialties.Select(s => 
        new SelectListItem {
            Text = s.Name,
            Value = s.id
        }
    ).ToArray();

    var viewModel = new CreateDoctorSubSpecialtyViewModel {
        DoctorProfiles = doctorProfiles,
        SubSpecialties = subSpecialties 
    };

    return View("Create", viewModel);
}

@model CreateDoctorSubSpecialtyViewModel
@using (Html.BeginForm("Create", "YourControllerName", FormMethod.Post)) {

    @Html.DropDownListFor(m => m.DoctorId, Model.DoctorProfiles)

    @Html.DropDownListFor(m => m.SubSpecialtyIds, Model.SubSpecialties, new { multiple = "multiple" })

    <input type="submit" />
}

[HttpPost]
[ValidateAntiForgeryToken]
public async Task<ActionResult> Create(CreateDoctorSubSpecialtyViewModel postData) {

    DoctorSubSpecialty[] allSelectedSubSpecialities = db.DoctorSubSpecialties
        .Where(d => d.DoctorId == postData.DoctorId 
                 && postData.SubSpecialtyIds.Contains(d.SubSpecialtyId)) 
        .ToArray();

    // ...
}