How to get Selected Value in DropDownList from Database - asp.net-mvc

Question

I want to get selected value in dropdownlist.
My View:
<div class="form-group">
#Html.LabelFor(model => model.AccountRefNo, "Account Desc", new { #class = "control-label col-md-2" })
<div class="col-md-10">
#Html.DropDownList("AccountRefNo", ViewBag.AccountRefNo as SelectList, "Account Desc", new { #class = "form-control" })
#Html.ValidationMessageFor(model => model.AccountRefNo)
</div>
</div>
<div class="form-group">
#Html.LabelFor(model => model.PartyID, "Party Type", new { #class = "control-label col-md-2" })
<div class="col-md-10">
#Html.DropDownList("TypeID", ViewBag.TypeID as SelectList, "Party Type", new { #class = "form-control" })
#Html.ValidationMessageFor(model => model.TypeID)
</div>
</div>
And, my Controller:
ViewBag.TypeID = new SelectList(db.PartyTypes, "TypeID", "TypeDesc", party.TypeID);
string[] codes = { "2.20.40.10", "3.50.10.20" };
ViewBag.AccountRefNo = new SelectList(db.ChartOfAccounts.Where(a => codes.Contains (a.AccountCode)), "AccountCode", "AccountDesc", party.AccountRefNo);
return View(party);
It seems it is OK but I don't know where the problem is. Both dropdownlists filling the lists but both are selecting their OptionLabel i.e selecting "Party Type" and "Account Desc" respectively.
Please help. Thanks!

Answer 1

This is in Edit controller and following worked.
string typeDescSelected = (from sub in db.PartyTypes
where sub.TypeID == party.TypeID
select sub.TypeDesc).First();
ViewBag.TypeDesc = new SelectList(db.PartyTypes, "TypeID", "TypeDesc", typeDescSelected);
string[] codes = { "2.20.40.10", "3.50.10.20" };
string accountDescSelected = (from sub in db.ChartOfAccounts
where sub.AccountCode == party.AccountRefNo
select sub.AccountDesc).First();
ViewBag.AccountDesc = new SelectList(db.ChartOfAccounts, "AccountCode", "AccountDesc", accountDescSelected);
return View(party);

Answer 2

SelectList constructors' first parameter needs to take a collection of SelectListItem:
Try the following and it should work provided there is data (void of null refs on PartyTypes and ChartOfAccounts:
ViewBag.TypeID = new SelectList
(
db.PartyTypes.Select(m=>new SelectListItem {Text=m.TypeDesc, Value=m.TypeID})
, "TypeID"
, "TypeDesc"
, party.TypeID
);
ViewBag.AccountRefNo = new SelectList
(
db.ChartOfAccounts
.Where(a => codes.Contains (a.AccountCode))
.Select(m=>new SelectListItem({Text=m.AccountDesc, Value=m.AccountCode}))
, "AccountCode"
, "AccountDesc"
, party.AccountRefNo //this maybe wrong
);
Also if ViewBag.AccountRefNo and party.AccountRefNo are the same type, then the last argument for the second SelectList constructor has to be incorrect. The argument should be the selected value so most likely party.AccountCode?