Question

我有4个下拉菜单，插入工作正常，如何编辑数据并将数据保存到db mvc2。我在更新时遇到错误 - 具有键'SelectedTimeZone'的ViewData项的类型为'System.String'但必须是'IEnumerable

类型

My Controller

    public ActionResult Edit(int id)
            {
                return View(EventModel.Edit(id));

            }

            [AcceptVerbs(HttpVerbs.Post)]
            [ValidateInput(false)] 
            public ActionResult Edit(int id, EventInfo EventInfo)
            {

                    if (ModelState.IsValid)
                    {
                        EventModel.Edit(EventInfo);
                        return RedirectToAction("Index");
                    }
                    return View(EventInfo); 

            }

Model

    public SelectList TimeZones { get; set; }
            public SelectList EventType { get; set; }

            private string selectedTimeZone = "";
            public string SelectedTimeZone
            {
                get { return selectedTimeZone; }
                set { selectedTimeZone = value; }
            }


   Load Function



      myEventInfo.TimeZones = new SelectList(EventModel.getTIMEZOMES, "Key", "Value");
         myEventInfo.SelectedTimeZone = Datareader["TIMEZONE"].ToString();

    public static IList<KeyValuePair<string, string>> getTIMEZOMES
            {
                get
                {
                    Dbhelper DbHelper = new Dbhelper();
                    IList<KeyValuePair<String, String>> Timezone = new List<KeyValuePair<String, String>>();
                    DbCommand cmd = DbHelper.GetSqlStringCommond("SELECT * FROM TMP_TIMEZONES");
                    DbDataReader Datareader = DbHelper.ExecuteReader(cmd);
                    while (Datareader.Read())
                    {
                        Timezone.Add(new KeyValuePair<String, String>(Datareader["ABBR"].ToString(), Datareader["NAME"].ToString()));
                    }

                    return Timezone;
                }
            }

View page

     <%= Html.DropDownListFor(model => model.SelectedTimeZone, Model.TimeZones, "Select Timezone", new { style = "width:200px", @class = "textfield165" })%>
                            <%= Html.ValidationMessageFor(model => model.SelectedTimeZone)%>

我在更新时遇到错误/具有键'SelectedTimeZone'的ViewData项的类型为'System.String'，但必须是'IEnumerable

类型

Answer 1

在您的POST操作中，如果出现错误，您忘记填充TimeZones属性。不要忘记只有选定的时区是POSTed，而不是时区列表，所以如果您打算重新显示相同的视图（例如出现错误），请确保重新绑定此列表（与绑定它的方式相同）在允许您在第一个位置显示表单的GET操作中：

[AcceptVerbs(HttpVerbs.Post)]
[ValidateInput(false)] 
public ActionResult Edit(int id, EventInfo EventInfo)
{
    if (ModelState.IsValid)
    {
        EventModel.Edit(EventInfo);
        return RedirectToAction("Index");
    }

    // Here you must populate the TimeZones property before returning the view
    EventInfo.TimeZones = new SelectList(EventModel.getTIMEZOMES, "Key", "Value");
    return View(EventInfo); 
}

我有4个下拉菜单，如何编辑和保存数据mvc2

1 个答案: