ASP.Net脚手架MVC努力使用实体框架填充下拉列表

Question

I'm struggling to conceptualise this because every resource I have found on Google has presented a different way to do it.

I have, at the moment generated razor views pertaining to a scaffolded controller using entity Framework. My controller looks like this:

    // GET: tbl_computerinfo
    public ActionResult Index()
    {
        var tbl_computerinfo = db.tbl_computerinfo.Include(t => t.tbl_equipment);
        tbl_computerinfo = tbl_computerinfo.Where(c => c.Company == "Company Name");
        return View(tbl_computerinfo.ToList());
    }

My Model is quite large but is just a generated entity framework model built on two tables linked with a foreign key tbl_computerinfo and tbl_equipment.

There is a string field called company in tbl_computerinfo. I need to select all the unique company values in the database and then use that to populate a dropdown which would exist on the index view. The selection of a company on that dropdown list should then filter the results in index view to only pull back entries with that company name. Any pointing in the right direction would be gratefully appreciated.

Answer 1

You need to create a ViewModel:

public class ComputerInfoViewModel
{
    public List<string> CompanyList {get; set;}
    public ComputerInfo ComputerInfo {get; set;}
}

In your Index method you populate this and pass it to the View:

public ActionResult Index()
    {
        var model = new ComputerInfoViewModel
        {
            CompanyList = /* populate this with your list of companies  */
            ComputerInfo = /* populate this with what? */
        };

        return View(model);
    }

In your View, you declare the model:

@model ComputerInfoViewModel

And you can access the model properties for display using @Model.CompanyList and @Model.ComputerInfo