Question

I have a table in my DB like:

I want to fill the select tag with the MainTab items using the Html.DropDownListFor() extension.

The hardest part is, I want these items to be a string like TabA_Name/TabB_Name/TabC_Name How can I do this ?

Answer 1

Use View Model for the page that you have dropdownlist. For instance,

public class MyViewModel
{
    /* You will keep all your dropdownlist items here */
    public IEnumerable<SelectListItem> Items { get; set; }

    /* The selected value of dropdown will be here, when it is posted back */
    public String DropDownListResult         { get; set; }

}

In your controller where you return view model to view, fill the list and return that model.

public ActionResult Create()
{
    /* Create viewmodel and fill the list */
    var model = new MyViewModel();

    // TODO : Select all data from MainTab to variable. Sth like below.
    var data= unitOfWork.Reposityory.GetAll();

    /* Foreach of the MainTab entity create a SelectListItem */
    var dropDownListData =  data.Select().(x = > new SelectListItem 
    {
        /* Value of SelectListItem is the pk of MainTab entity. */
        Value = x.MainTabID,

        /* This is the string you want to display in dropdown */
        Text = x.TabA.Name + "/" + x.TabB.Name + "/" + x.TabC.Name
    });

    model.Items = new SelectList(dropdownListData, "Value", "Text");

    return View(model);
}

This is your view.

/* Make your view strongly typed via your view model */
@model MyNamespace.MyViewModel

/* Define your dropdown such that the selected value is binded back to 
 * DropDownListResult propery in your view model */
@Html.DropDownListFor(m => m.DropDownListResult, Model.Items)

When you post your view back to controller, your view model should have DropDownListResult that is filled with the selected dropdownlist item.