Cannot display SelectList values from Lambda in Razor

0
votes

In MVC.

I am getting this error message when trying to display a dropDownList in Razor.

DataBinding: 'System.Int32' does not contain a property with the name 'BranchId'.

In the watch window I am able to see 1 record is being returned from the database containing a BranchId and BranchName I have no reference to the SelectList in the Model class.

In the Controller class

var list = new SelectList(db.Branchs.Where(branches => !db.CompanyBranches
    .Any(d => d.BranchId == branches.BranchId))
    .Select(branches => branches.BranchId).ToList(), 
    "BranchId", "BranchNumber");
ViewBag.Branch = new SelectList(list);

In the Create.cshtml

@Html.DropDownList("Branch", new SelectList(ViewBag.Branch, "BranchID", "BranchName"), htmlAttributes: new { @class = "form-control" })

Thanks Stephen

I changed the lambda expression in my CompanyBranchesController as you suggested it is now var list = db.Branchs.Where(branches => !db.CompanyBranches .Any(d => d.BranchId == branches.BranchId)) .Select(b => new { BranchId = b.BranchId, BranchName = b.BranchName }).ToList();

The Create.cshtml for the dropdownlist is @Html.DropDownList("Branch", ViewBag.Branch as IEnumerable, htmlAttributes: new { @class = "form-control" })

The result in the dropdownlist is {BranchId = 5, BranchNumber = Br0003}

I have been playing with it including adding to the CompanyBranchController List items = new List(); foreach (var i in list) { SelectListItem s = new SelectListItem(); s.Text = i.BranchName.ToString(); s.Value = i.BranchId.ToString(); items.Add(s);
}

As well as trying different razor expressions but with no success.

Any Idea where I am going wrong?

2
asp.net-mvcrazor

2 Answers

1
votes

Look at this part of your code (The SelectList constructor)

Select(branches => branches.BranchId).ToList()

You are selecting the branchId's. So basically you are passing a list of integers to the SelectList constructor. But you specify that BranchId is the data value field. But the integer does not have such a property.

So you should change your Select to an annonymous type which has this properties

Select(b => new { BranchId = b.BranchId, BranchNumber = b.BranchId).ToList()

Also you do not need to create another SelectList again when you assign to the ViewBag. So this is good enough

ViewBag.Branch = list;

and in your view,

 @Html.DropDownList("Branch", ViewBag.Branch as IEnumerable<SelectListItem>, 
                                         htmlAttributes: new { @class = "form-control" })

Or even easier, you may simply convert your items to a list of SelectListItem

var list= db.Branchs.Where( // Put your where clause here)
            .Select(branches => new SelectListItem { Value = branches.BranchId.ToString(),
                                       Text = branches.BranchId.ToString()}).ToList();
ViewBag.Branch = list;
0
votes

Your code was correct except that in the CompanyBranchContoller I added

List<SelectListItem> items = new List<SelectListItem>();
                foreach (var i in list)
                {
                    SelectListItem s = new SelectListItem();
                    s.Text = i.BranchName.ToString();
                    s.Value = i.BranchId.ToString();
                    items.Add(s);                    
                }

ViewBag.Branch = items;

Then in the Create.cshtml class I changed the reference to the dropdown list to what you suggested:

 @Html.DropDownList("Branch", ViewBag.Branch as IEnumerable<SelectListItem>, htmlAttributes: new { @class = "form-control" })

Thanks for all of your help Stephen

Paul