How do I map checkboxes onto MVC model members?

Question

I have an MVC view

<%@ Page Language=\"C#\" MasterPageFile=\"PathToMaster\" Inherits=\"System.Web.Mvc.ViewPage\" %>

and

Answer 1

First you define SelectList for Options. This will be used just to render checkboxes

    public IList OptionsSelectList { get; set; }

Than, you define model that will hold value of single chosen option after post

public class ChooseOptionViewModel
{
    public int OptionIdentifier { get; set; } //name or id
    public bool HasBeenChosen { get; set; } //this is mapped to checkbox
}

Then IList of those options in ModelData

public IList Options { get; set; }

And finally, the view

    @for (int i = 0; i < Model.OptionsSelectList.Count(); i++)
    {
        
            
                @Html.Hidden("Options[" + i + "].OptionIdentifier", Model.OptionsSelectList[i].Value)
            
            
                @Model.OptionsSelectList[i].Text
            
            
                @Html.CheckBox("Options[" + i + "].HasBeenChosen", Model.Options != null && Model.Options.Any(x => x.OptionIdentifier.ToString().Equals(Model.OptionsSelectList[i].Value) && x.HasBeenChosen))
            
        
    }

After post, you just inspect Options.Where(x => x.HasBeenChosen)

This is full-functional, and it will allow you to redisplay view when validation errors occur, etc. This seems a bit complicated, but I haven't come up with any better solution than this.