ASP MVC Using a ViewModel

Question

I'm in a situation where I'd like to have two models in my view. I've been trying to do it as in the controller below, but I'm not sure how the proper way is to do it, but I'm assuming it's something with making an instance of the WellViewModel and then creating and adding to the respective lists, the WellViewModel contains but I think I've been muddling it up a little since I can't seem to get it to work. Any hints?

These are my models which I've put into a ViewModel:

public class WellViewModel
{
    public List<WellModel> Wells { get; set; }
    public List<AnnotationModel> Annotations { get; set; }  
}

And this is where I retrieve the data from the database:

    public ActionResult Well(string slideid)
    {
        WellViewModel model = new WellViewModel();
        string cs = dbPath;
        using (SQLiteConnection con = new SQLiteConnection(cs))
        {
            string stm = "SELECT * FROM Well WHERE SlideId = " + "'" + slideid + "'";
            con.Open();
            using (SQLiteCommand cmd = new SQLiteCommand(stm, con))
            {
                using (SQLiteDataReader rdr = cmd.ExecuteReader())
                {
                    while (rdr.Read())
                    {
                        model.Wells = new List<WellModel>() { new WellModel()} //This is not possible to do
                        {
                            SlideId = rdr["SlideId"].ToString(),
                            Well = int.Parse(rdr["Well"].ToString()),
                            TimeStamp = rdr["TimeStamp"].ToString()
                        };
                    }
                    rdr.Close();
                }
            }
            con.Close();
        }       
        using (SQLiteConnection con = new SQLiteConnection(cs))
        {
            string stm = "SELECT * FROM Annotation WHERE SlideId = " + "'" + slideid + "'";
            con.Open();
            using (SQLiteCommand cmd = new SQLiteCommand(stm, con))
            {
                using (SQLiteDataReader rdr = cmd.ExecuteReader())
                {
                    while (rdr.Read())
                    {
                        Annotations = new AnnotationModel
                        {
                            SlideId = rdr["SlideId"].ToString(),
                            Well = int.Parse(rdr["Well"].ToString()),
                            Par = rdr["Par"].ToString(),
                            Time = rdr["Time"].ToString(),
                            Val = rdr["Val"].ToString(),
                            TimeStamp = rdr["TimeStamp"].ToString()
                        };
                    }
                    rdr.Close();
                }
            }
            con.Close();
        }

        return View(model);
    }

Ric · Accepted Answer · 2015-10-01 10:31:10Z

3

In your while loop, you create a new List<WellModel> and add a single item.

Instead, define it like so:

WellViewModel model = new WellViewModel();
model.Wells = new List<WellModel>();
model.Annotations = new List<AnnotationModel>();

while (rdr.Read())
{
    model.Wells.Add(new WellModel { // set values here };
}

Do the same for your other List of Annotations.

answered Oct 1, 2015 at 10:31

Ric

13.3k3 gold badges32 silver badges36 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Andrei · Accepted Answer · 2015-10-01 10:30:45Z

2

The only problem that I see with your code is improper use or reader to fill the lists with data. You should initialize a list outside the reading loop, and then just add new items to it:

model.Wells = new List<WellModel>();
using (SQLiteConnection con = new SQLiteConnection(cs))
{
....

while (rdr.Read())
{
    WellModel well = new WellModel
        {
            SlideId = rdr["SlideId"].ToString(),
            Well = int.Parse(rdr["Well"].ToString()),
            TimeStamp = rdr["TimeStamp"].ToString()
        };
    model.Wells.Add(well);
}

Likewise for the other list.

answered Oct 1, 2015 at 10:30

Andrei

56.8k10 gold badges92 silver badges114 bronze badges

Comments

brothers28 · Accepted Answer · 2015-10-01 11:39:05Z

2

I think it will be the best if you add a Constructor to your WellViewModel where you can set your WellModel List an your AnnotationModel List.

Like so:

public class WellViewModel
{
   public WellViewModel()
   {
       Wells = new List<WellModel>();
       Annotaions = new List<AnnotationModel>();
   }

   public List<WellModel> Wells { get; set; }
   public List<AnnotationModel> Annotations { get; set; }  
}

In your while loop then you can just add new WellModel / AnnotationModel.

while (rdr.Read())
{
    model.Wells.Add(new WellModel() 
    { 
       // set values here 
    });
}

edited Oct 1, 2015 at 11:39

answered Oct 1, 2015 at 10:35

brothers28

1,20619 silver badges24 bronze badges

2 Comments

brothers28 Over a year ago

Thanks @Ric. This is my normal approach because it is very easy and you don't have to remember setting your List first...

brothers28 Over a year ago

@Ric Yeah it's a common problem but like that it's way easier to handel

Collectives™ on Stack Overflow

ASP MVC Using a ViewModel

3 Answers 3

Comments

Comments

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related