MVC实体框架DropDownListFor<> [英] MVC Entity Framework DropDownListFor<>

问题描述

我想遵循最佳的MVC最佳实践来创建DropList。

I would like to follow best MVC best practise for creating DropLists.

我有3个模型（为此我将它们缩减了）

I have 3 Models (I have cut them down for the purposes of this)

模型一
学生

public int ID {get;set;}
public string Name {get;set}
public Site SiteID {get;set;}

模型二
站点

public int ID {get;set;}
public string SiteName {get;set}

模型三
VM

Model Three VM

public int ID {get;set}
public student Students {get;set;}

public DateTime Date  { get { return DateTime.Now; } }
public bool Criteria {get;set;}

在我的VM视图中，我是使用EditorFor html助手来填充我的VM和学生模型。该站点模型已预先填充在数据库种子中。

In my VM view I am using EditorFor html helpers to populate my VM and Student Models. The site model is pre populated at the database seed.

我正在寻找在VM视图中包括站点下拉列表的最佳方法，该列表将映射到我的学生

I am looking for the best way to include a dropdownlist of sites on my VM view, that will map to my student model.

如何正确设置模型来实现这一目标？

How to I correctly set up my models to achieve this?

推荐答案

简而言之，您需要 DropDownListFor 扩展方法，并将 List< Site> 放入视图模型。

In short, you want the DropDownListFor extension method and to put a List<Site> into the view model.

演示您情况的小提琴。小提琴有更多细节。螺母和螺栓在这里：

Here is a Fiddle that demonstrates your case. The Fiddle has more details. The nuts and bolts are here:

public class MyViewModel
{
    public MyViewModel()
    {
        this.Sites = new List<Site>();
    }

    public int ID { get; set;}
    public Student Students { get; set; }

    public DateTime Date  { get { return DateTime.Now; } }
    public bool Criteria { get; set; }      

    public List<Site> Sites { get; set; }
}

视图-使用 DropDownListFor

View - Use DropDownListFor

@Html.DropDownListFor(m => m.Sites, 
    new SelectList(Model.Sites, "ID", "SiteName"))

在伪代码中，上面说的是

In psuedo-code, the above says

• 模型中的站点对象包含要显示的属性。


• 使用模型中的站点对象创建新的 SelectList 。使用 ID 属性作为数据值，并使用 SiteName 属性作为数据文本。


• 基于上述信息创建一个下拉列表。

• The Sites object in the model contains the properties to display.
• Create a new SelectList using the Sites object in the model. Use the ID property as the data value and the SiteName property as the data text.
• Create a drop down list based on the above info.

这只是将种子视图模型传递给视图。

This just passes a seeded view model to the view.

public ActionResult Index()
{
    var vm = SeedFromDatabase();
    return View(vm);
}

private MyViewModel SeedFromDatabase()
{
    var vm = new MyViewModel();
    vm.Sites.Add(new Site(0, "one"));
    vm.Sites.Add(new Site(1, "two"));
    vm.Sites.Add(new Site(2, "three"));
    return vm;
}

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