Question

I have a problem with my code snippet inside the MVC 3 with Razor syntax. In my DB table (MySQL), I have a colum (FK) LanguageID [int]. Then, in that View, I want to assign to that column to the DropDownList with the languages list that I generate on the fly:

     List<SelectListItem> list = new List<SelectListItem>();

     list.Add(new SelectListItem
                    {
                        Value = tableRow.ID.ToString()
                        ,
                        Text = "language"
                    }

Then, in the View, I connects that list to the Language property:

@Html.DropDownListFor(
                 model => model.Language, 
                 new SelectList(ViewData["LanguageList"] as List<SelectListItem>,
                "Value", "Text")
                    )

but, when I post the data to the server, it returns with the error result "The value '353' is invalid." where the 353 is the Language ID from the DB. What am I doing wrong ?

Edit
Whle debugging, I’ve noticed the error message within the ModelState: "The parameter conversion from type 'System.String' to type 'FavorytaWeb.Models.BookLanguage' failed because no type converter can convert between these types."

Answer 1

Replace:

@Html.DropDownListFor(
    model => model.Language, 
    ...
)

with:

@Html.DropDownListFor(
    model => model.Language.LanguageID, 
    ...
)

You cannot bind the value 353 to a complex type which is what model.Language represents. It just doesn’t make sense. You can bind it only to scalar properties.