ASP.NET Core MVC Xreturn view multiple values

Question

I am showing checkbox list in my ASP.NET Core MVC project. I am pulling data from a database. I don't have any problems displaying one item, but if I want to show more than one item, I get a problem. How can I solve it?

public IActionResult Create()
{
    var item = _context.Cihazlar.ToList();

    StudentCourseViewModel m1 = new StudentCourseViewModel();
    m1.AvailableCourses = item.Select(vm => new CheckBoxItem()
            {
                Id = vm.Id,
                Title = vm.Model,
               IsChecked = false
            }).ToList(); 
 
     return View(m1);
}

There is no problem in my code as above. The checkboxlist in m1 appears on the page, but if I make my code as below, I get an error.

public IActionResult Create()
{
    var item = _context.Cihazlar.ToList();

    StudentCourseViewModel m1 = new StudentCourseViewModel();
    m1.AvailableCourses = item.Select(vm => new CheckBoxItem()
            {
                Id = vm.Id,
                Title = vm.Model,
               IsChecked = false
            }).ToList(); 
 
    var item2 = _context.HardwareSoftware.ToList();

    StudentCourseViewModel m2 = new StudentCourseViewModel();            
    m2.AvailableCourses2 = item2.Select(vm => new CheckBoxItem()
            {
                Id = vm.Hardware_Software_Id,
                Title = vm.Hardware_Software_Name,
                IsChecked = false
            }).ToList();
 
    return View(m1, m2);
}

How can I show m1 and m2 at the same time?

Answer 1

As suggested in the comment above, you can make like the following.

Declare a compound data model:

public class UnitedViewModel 
{
    public StudentCourseViewModel CihazlarCourses { get; set; } // Cihazlar
    public StudentCourseViewModel HSCourses { get; set; } // HardwareSoftware
}

The Create action method:

public IActionResult Create()
{
    var model = new UnitedViewModel();

    var item = _context.Cihazlar.ToList();

    model.CihazlarCourses = new StudentCourseViewModel();
    model.CihazlarCourses.AvailableCourses = item.Select(vm => new CheckBoxItem()
            {
                Id = vm.Id,
                Title = vm.Model,
               IsChecked = false
            }).ToList(); 

    var item2 = _context.HardwareSoftware.ToList();

    model.HSCourses = new StudentCourseViewModel();            
    model.HSCourses.AvailableCourses = item2.Select(vm => new CheckBoxItem()
            {
                Id = vm.Hardware_Software_Id,
                Title = vm.Hardware_Software_Name,
                IsChecked = false
            }).ToList();

    return View(model);
}

Then declare the data view model in the Create.cshml as below:

@model UnitedViewModel 
   
    .... Your code here will use the `@Model.CihazlarCourses` and the `@Model.HSCourses`