Question

I used Linq to Entity, for fetch a model from DB

 var works = db.Work.Where(a => a.StartDate == DateTime.Now).ToList();

this model contain a DateTime that I want to change it to string before send it to view
beacuase need to show it as a persianDate Time,
like this :

    foreach (var item in workslist)
                {
                    item.StartDate = "1391/01/01"; //Just For Exapmle as you know this won't work
                }
return View(workslist);

So is there any way to change a data type in a strongly typed model? or other way to do this except save DateTime as String in my DB

Answer 1

You can use the [DisplayFormat] attribute with EditorFor/DisplayFor helpers to format the data.

[DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:yyyy/mm/dd}")]
public DateTime StartDate { get; set; }

Then in view:

@Html.EditorFor(m => m.StartDate)

OR, you can also consider to define separate ViewModel for your ‘Work’ domain model. Though this approach results in more code, it’s provide more flexibility and considered as good practice.
Here is sample code:

public class Work
{
    public DateTime StartDate {get;set;}
}

public class WorkViewModel
{
    public WorkViewModel()
    {
    }

    public string StartDate { get; set; }

    public static WorkViewModel Map(Work domainModel)
    {
        return new WorkViewModel() { 
            //Apply your Date format logic
            StartDate = domainModel.StartDate.ToString("yyyy/MM/dd")
        };
    }
}

In action method:

var works = db.Work.Where(a => a.StartDate == DateTime.Now).ToList();
var workViewModels = new List<WorkViewModel>(works.Count);
foreach (var work in works)
    workViewModels.Add(WorkViewModel.Map(work));

return View(workViewModels);