ASP.NET MVC: How to transfer more than one object to View method?

问题

I finished NerdDinner tutorial and now I'm playing a bit with project. Index page shows all upcoming dinners:

    public ActionResult Index()
    {
        var dinners = dinnerRepository.FindUpComingDinners().ToList();
        return View(dinners);
    }

In DinnerRepository class I have method FindAllDinners and I would like to add to above Index method number of all dinners, something like this:

    public ActionResult Index()
    {
        var dinners = dinnerRepository.FindUpComingDinners().ToList();
        var numberOfAllDinners = dinnerRepository.FindAllDinners().Count();
        return View(dinners, numberOfAllDinners);
    }

Of course, this doesn't work. As I'm pretty new to OOP I would need help with this one.

Thanks,
Ile

回答1:

Create view model:

public class DinnerViewModel
{
    public List<Dinner> Dinners { get; set; }
    public int NumberOfAllDinners { get; set; }
}

public ActionResult Index()
{
    var dinners = dinnerRepository.FindUpComingDinners().ToList();
    var numberOfAllDinners = dinnerRepository.FindAllDinners().Count();
    return View(new DinnerViewModel { Dinners = dinners, NumberOfAllDinners = numberOfAllDinners } );
}

回答2:

You need to create a "wrapper" object that contains the objects you wish to pass as public properties of it. For instance, create an object called DinnerViewModel and give it two properties and set these with two properties, one a List called Dinners and one an int called DinnerCount. Then pass the DinnerViewModel to the view and you can then access Model.Dinners and Model.DinnerCount

回答3:

In your case I would prefer the solution mentioned by LukLed.

In general you could of course also transfer multiple values from your controller to your view using ViewData:

ViewData["dinners"] = dinners;
ViewData["numberOfAllDinners"] = 150;
...

For more information also take a look at this link.

回答4:

Just simply use dinners.Count property instead.

回答5:

Remember, you start off using the ViewData inherts in you .aspx filesand returning the same in you return statements. Because of that, I figure that it was an issue with the Inherits attribute on the top of the ASP.NET files. But, if you are getting the error when trying to create or edit a new Dinner when you are on the 'Upcoming Dinners' page (generated from the Details.aspx and the LINQ file that gets all Dinners that are after todays date), go into your 'Controllers' directory, specifically the DinnerController.cs. Then look at the Edit and or Create methods. the answer lies right here. If you put breakpoints on these methods, you should be able to figure it out. If not, continue reading:

Look where it fails, the 'return...' line. Maybe I am the only person who forgot to change this, but my error is the same as people are getting in this page and this os how I fixed it.....the 'return(dinner)' line, in Create and Edit (and any others that you are having issues with), they are using the NerDinner.Model.Dinner / ViewData method. However, if you change it to the ViewModel return method instead, it should fix it, For example: 'return(new DinnerFormViewModel(dinner));', it should work for you. I hope this helps, as it was what my issue was. Just a simple overlook.

来源：https://stackoverflow.com/questions/2484852/asp-net-mvc-how-to-transfer-more-than-one-object-to-view-method

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ASP.NET

asp.net-mvc

object

nerddinner