如何获得关联关系

Posted 2023-03-27

【中文标题】如何获得关联关系

【英文标题】：How to get a linked relationship

【发布时间】：2021-10-07 13:14:30

【问题描述】：

我有基础模型

public class Group

    public int Id  get; set; 
    public int GroupVag  get; set; 
    public ICollection<Vagon> Vagons  get; set; 


public class Vagon 

    public int Id  get; set; 
    public string Nom_Vag  get; set; 
    //[Required]
    public int NumberGroup  get; set; 
    [ForeignKey("Group")]
    public int? GroupId  get; set; 
    public Group Group  get; set; 
    public virtual ICollection<SPR4664> SPR4664s  get; set; 

我的视图模型

public class ViewModelAddVag

    public int Id  get; set; 
    [Display(Name = "Name vag")]
    [Required]
    [MaxLength(8, ErrorMessage = "incorrect")]
    public string Nom_Vag  get; set; 

    [Display(Name = "Group vag")]
    //[Required]
    public int NumberGroup  get; set; 
    [Display(Name = "TrainingType")]
    [UIHint("DropDownList")]
    public IEnumerable<SelectListItem> GroupDictionary  get; set; 

我想加入 View DropDownList table Group。 我为它做了 ViewModel。但我不知道该怎么做？ 我想我应该在 ViewModel 使用属性 Get 中得到它

public IEnumerable<SelectListItem> GroupDictionary  get; set; 

【参考方案1】：

我想得到什么：

查看

<div class="form-group">
        <div class="col-md-10">
            
                Grops <br />
                @html.DropDownListFor(model => model.Id, ViewBag.Group as SelectList, null, new  @class = "btn btn-info dropdown-toggle" )
            
            <select name="TrainingTypeId" class="btn btn-light dropdown-toggle dropdown-toggle-split" aria-label="Default select example">
                @foreach (var item in ViewBag.Group)
                
                    <option value="@item.Value">
                        @item.Text
                    </option>
                
            </select>
            </div>
        </div>

控制器：

    [HttpGet]
    public ActionResult Create()
    
        SelectList groupsList = new SelectList(db.groups, "Id", "GroupVag");
        ViewBag.Group = groupsList;
        return View();