Question

我想在下拉列表中获取所选值。

我的观点：

procedure TForm1.DBNavigator1BeforeAction(Sender: TObject; Button:
    TNavigateBtn);
var
  Res : Integer;
  DataSet : TDataSet;
begin
  DataSet := DBNavigator1.DataSource.DataSet;
  case Button of
    nbFirst,
    nbPrior,
    nbNext,
    nbLast: begin
      if DataSet.State in [dsEdit, dsInsert] then begin
        Res := MessageDlg('The current row has unsaved changes.  Abandon them?', mtWarning, [mbYes, mbNo], 0);
        if Res = mrYes then
          DataSet.Cancel
        else
          DataSet.Post;
      end;
    end;
  end;
end;

而且，我的控制器：

<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>

似乎没关系，但我不知道问题出在哪里。两个下拉列表都填写了列表，但两者都选择了他们的OptionLabel，即分别选择“Party Type”和“Account Desc”。

请帮忙。谢谢！

Answer 1

SelectList构造函数＆＃39;第一个参数需要采用SelectListItem的集合：

尝试以下操作，只要有数据，它就应该有效（在PartyTypes和ChartOfAccounts上为null引用：

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 
    );

此外，如果ViewBag.AccountRefNo和party.AccountRefNo是同一类型，则第二个SelectList构造函数的最后一个参数必须不正确。参数应该是选定的值，所以很可能是party.AccountCode？

Answer 2

这是在编辑控制器中，然后工作。

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);

如何从数据库中获取DropDownList中的选定值

2 个答案: