I can't fetch data from the db with a Html.DropDownListFor, in MVC 4 (or 5) - model-view-controller

Question

I have read some pages regarding DDls, but I can't get my DDLF (DropDownListFor) to work. I have a model, and a db, but I don't know how I can in the view show one DDLF.
What I get to work, is this code:
#foreach (var item in Model)
{
#Html.DropDownListFor(m => item.Id,
new SelectList(ViewBag.SjukhusDropDownList),
"Choose something")
}
But then I get several DDLs. And I don't know how to insert data into them, so the data to the user will get fetched from the db. Like sending an id with something to the action, to do something with it. But here, I can only click on anything in the list, but of course, nothing will happen since I haven't bound any data to any option in that select list.

Answer 1

Here's an example for DropDownListFor in MVC 4
In the model create two properties, one for the list itself and one for identifying the list entries. In this example the vu-number identifies a merchant:
public class MyModel
{
[Display(Name = "VU")]
public string vu{ get; set; }
public List<SelectListItem> merchantList{ get; set; }
}
Initialize and load model data in the Http GET method of the controller:
public ActionResult ShowMerchants()
{
MyModel model = new MyModel();
model.merchantList = GetMerchants();
model.vu = model.merchantList[0].Value;
return View(model);
}
Create the list items using some rows from database. I.e. you can use TableAdapter and DataTable to achieve it:
private List<SelectListItem> GetMerchants()
{
List<SelectListItem> merchantList = new List<SelectListItem>();
MyDataSet.viewVUDataTable myDataTable = new MyDataSet.viewVUDataTable();
MyDataTableAdapters.VUListTableAdapter myTableAdapter = new MyDataTableAdapters.VUListTableAdapter();
myTableAdapter.Fill(myDataTable);
// iterate over rows in datatable
for(int i=0; i< myDataTable.Rows.Count; i++)
{
// Text is shown in the dropdownlist
// Value is used to identify the selected item
merchantList.Add(
new SelectListItem { Text = myDataTable[i].text, Value = myDataTable[i].vu});
}
return merchantList;
}
and in the view:
#Html.DropDownListFor(
model => model.vu,
Model.merchantList,
new { #class = "form-control" })