在 ASP.Net MVC 中使用 DropDownList 的最佳编程实践 [英] Best programming practice of using DropDownList in ASP.Net MVC

问题描述

我用 MVC 5 工作了几个月，阅读了很多文章、论坛和文档，但总是想知道在视图中什么更好；

I'm working with MVC 5 for a few months read a lot of articles, forums and documentation but always wondering what is better in the view;

1) 使用模型的静态方法绑定数据，例如 here

1) binding data using static method of model like here

2) 使用在控制器中设置的 ViewData[index] 绑定相同的数据，与前面的例子一样

2) binding the same data using ViewData[index] which is set in Controller that with previous example will look like this

@Html.DropDownListFor(n => n.MyColorId, ViewData[index])

推荐答案

你想使用选项1，主要是你想尽可能使用Strongly Type，并在编译时修复错误时间.

You want to use option 1, mainly because you want to use Strongly Type as much as possible, and fix the error at compile time.

相比之下，ViewData 和 ViewBag 是动态的，编译直到运行时才能捕获错误.

In contrast, ViewData and ViewBag are dynamic, and compile could not catch error until run-time.

这是我在许多应用程序中使用的示例代码 -

Here is the sample code I used in many applications -

public class SampleModel
{
    public string SelectedColorId { get; set; }
    public IList<SelectListItem> AvailableColors { get; set; }

    public SampleModel()
    {
        AvailableColors = new List<SelectListItem>();
    }
}

查看

@model DemoMvc.Models.SampleModel
@using (Html.BeginForm("Index", "Home"))
{
    @Html.DropDownListFor(m => m.SelectedColorId, Model.AvailableColors)
    <input type="submit" value="Submit"/>

}

控制器

public class HomeController : Controller
{
    public ActionResult Index()
    {
        var model = new SampleModel
        {
            AvailableColors = GetColorListItems()
        };
        return View(model);
    }

    [HttpPost]
    public ActionResult Index(SampleModel model)
    {
        if (ModelState.IsValid)
        {
            var colorId = model.SelectedColorId;
            return View("Success");
        }
        // If we got this far, something failed, redisplay form
        // ** IMPORTANT : Fill AvailableColors again; otherwise, DropDownList will be blank. **
        model.AvailableColors = GetColorListItems();
        return View(model);
    }

    private IList<SelectListItem> GetColorListItems()
    {
        // This could be from database.
        return new List<SelectListItem>
        {
            new SelectListItem {Text = "Orange", Value = "1"},
            new SelectListItem {Text = "Red", Value = "2"}
        };
    }
}

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