MVC 4简单填充下拉从数据库模型 [英] MVC 4 Simple Populate DropDown from database model

问题描述

我觉得自己有点笨。

我试图让MVC 4的窍门，用拳击作为一种功能性的例子。

I'm trying to get a hang of MVC 4, using boxing as a functional example.

我 WeightCategories 在数据库中（重量级等）和义和团。

I have WeightCategories in the database (Heavyweights, etc), and Boxers.

看起来似乎很简单。的关系是一个拳击手有一个当前体重级别，但是当我编辑，我希望它能够与一个下拉去改变它。

Seem simple. The relation is a boxer has a current weight category, but when I edit, I want it to be able to change it with a drop down.

我知道如何做到这一点，如果是我做了自己在code名单，但我有问题，理解如何装入从 WeightCategory 表并显示在拳击手的看法/模式。

I understand how to do it if it's a list I've made myself in the code, but I have problem understanding how to "load" the list from the WeightCategory table and show it in the view/model of the boxer.

所以，这里是我的code为 WeightCategory 项目：

So, here is my code for the WeightCategory item:

[Table("WeightCategories")]
public class WeightCategory
{
    [Key]
    public int WeightCategoryId { get; set; }

    public WEIGHT_CATEGORIES WeightCategoryType { get; set; }

    [Display(Name = "Weight Category Name")]
    [Required]
    [MinLength(5)]
    public string Name { get; set; }
    [Display(Name = "Weight Limit In Pounds")]        
    public int? WeightLimit { get; set; }
}

下面是code为拳击项目

Here is the code for the boxer item

[Table("Boxers")]
public class Boxer
{
    [Key]
    public int BoxerId { get; set; }

    public WeightCategory CurrentWeightCategory { get; set; }

    [Required]
    public string Name { get; set; }
    public int Wins { get; set; }
    public int Losses { get; set; }
    public int Draws { get; set; }
    public int Kayos { get; set; }
}

在看，我真的不知道如何解决的是，我在pretty确保它不是自动的，我需要的地方装载表控制器，也许......我在寻找最好的实践什么的。

In the view, I'm really not sure how to tackle that, I'm pretty sure it's not automatic and I need to load the table somewhere in the controller maybe... I'm looking for best practice or something.

类似的东西在视图中底：

Something like that in the view at the end:

@Html.DropDownListFor(model => model.CurrentWeightCategory.WeightCategoryId,
                      new SelectList(Model.WeightCategories, "WeightCategoryId", "Name", 
                                     Model.WeightCategories.First().WeightCategoryId))

谢谢！

推荐答案

您可以设计一个视图模型：

You could design a view model:

public class MyViewModel
{
    public Boxer Boxer { get; set; }
    public IEnumerable<SelectListItem> WeightCategories { get; set; }
}

再有你的控制器动作填充，并通过该视图模型到视图：

and then have your controller action populate and pass this view model to the view:

public ActionResult Edit(int id)
{
    var model = new MyViewModel();
    using (var db = new SomeDataContext())
    {
        // Get the boxer you would like to edit from the database
        model.Boxer = db.Boxers.Single(x => x.BoxerId == id);

        // Here you are selecting all the available weight categroies
        // from the database and projecting them to the IEnumerable<SelectListItem>
        model.WeightCategories = db.WeightCategories.ToList().Select(x => new SelectListItem
        {
            Value = x.WeightCategoryId.ToString(),
            Text = x.Name
        })
    }
    return View(model);
}

现在你的看法变成强类型的视图模型：

and now your view becomes strongly typed to the view model:

@model MyViewModel
@Html.DropDownListFor(
    x => model.Boxer.CurrentWeightCategory.WeightCategoryId,
    Model.WeightCategories
)

这篇关于MVC 4简单填充下拉从数据库模型的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！