So many ways to do this... for #NetCore use Lib..
using System;
using System.Collections.Generic;
using System.Linq; // only required when .AsEnumerable() is used
using System.ComponentModel.DataAnnotations;
using Microsoft.AspNetCore.Mvc.Rendering;
Model...
namespace MyProject.Models
{
public class MyModel
{
[Required]
[Display(Name = "State")]
public string StatePick { get; set; }
public string state { get; set; }
[StringLength(35, ErrorMessage = "State cannot be longer than 35 characters.")]
public SelectList StateList { get; set; }
}
}
Controller...
namespace MyProject.Controllers
{
/// <summary>
/// create SelectListItem from strings
/// </summary>
/// <param name="isValue">defaultValue is SelectListItem.Value is true, SelectListItem.Text if false</param>
/// <returns></returns>
private SelectListItem newItem(string value, string text, string defaultValue = "", bool isValue = false)
{
SelectListItem ss = new SelectListItem();
ss.Text = text;
ss.Value = value;
// select default by Value or Text
if (isValue && ss.Value == defaultValue || !isValue && ss.Text == defaultValue)
{
ss.Selected = true;
}
return ss;
}
/// <summary>
/// this pulls the state name from _context and sets it as the default for the selectList
/// </summary>
/// <param name="myState">sets default value for list of states</param>
/// <returns></returns>
private SelectList getStateList(string myState = "")
{
List<SelectListItem> states = new List<SelectListItem>();
SelectListItem chosen = new SelectListItem();
// set default selected state to OHIO
string defaultValue = "OH";
if (!string.IsNullOrEmpty(myState))
{
defaultValue = myState;
}
try
{
states.Add(newItem("AL", "Alabama", defaultValue, true));
states.Add(newItem("AK", "Alaska", defaultValue, true));
states.Add(newItem("AZ", "Arizona", defaultValue, true));
states.Add(newItem("AR", "Arkansas", defaultValue, true));
states.Add(newItem("CA", "California", defaultValue, true));
states.Add(newItem("CO", "Colorado", defaultValue, true));
states.Add(newItem("CT", "Connecticut", defaultValue, true));
states.Add(newItem("DE", "Delaware", defaultValue, true));
states.Add(newItem("DC", "District of Columbia", defaultValue, true));
states.Add(newItem("FL", "Florida", defaultValue, true));
states.Add(newItem("GA", "Georgia", defaultValue, true));
states.Add(newItem("HI", "Hawaii", defaultValue, true));
states.Add(newItem("ID", "Idaho", defaultValue, true));
states.Add(newItem("IL", "Illinois", defaultValue, true));
states.Add(newItem("IN", "Indiana", defaultValue, true));
states.Add(newItem("IA", "Iowa", defaultValue, true));
states.Add(newItem("KS", "Kansas", defaultValue, true));
states.Add(newItem("KY", "Kentucky", defaultValue, true));
states.Add(newItem("LA", "Louisiana", defaultValue, true));
states.Add(newItem("ME", "Maine", defaultValue, true));
states.Add(newItem("MD", "Maryland", defaultValue, true));
states.Add(newItem("MA", "Massachusetts", defaultValue, true));
states.Add(newItem("MI", "Michigan", defaultValue, true));
states.Add(newItem("MN", "Minnesota", defaultValue, true));
states.Add(newItem("MS", "Mississippi", defaultValue, true));
states.Add(newItem("MO", "Missouri", defaultValue, true));
states.Add(newItem("MT", "Montana", defaultValue, true));
states.Add(newItem("NE", "Nebraska", defaultValue, true));
states.Add(newItem("NV", "Nevada", defaultValue, true));
states.Add(newItem("NH", "New Hampshire", defaultValue, true));
states.Add(newItem("NJ", "New Jersey", defaultValue, true));
states.Add(newItem("NM", "New Mexico", defaultValue, true));
states.Add(newItem("NY", "New York", defaultValue, true));
states.Add(newItem("NC", "North Carolina", defaultValue, true));
states.Add(newItem("ND", "North Dakota", defaultValue, true));
states.Add(newItem("OH", "Ohio", defaultValue, true));
states.Add(newItem("OK", "Oklahoma", defaultValue, true));
states.Add(newItem("OR", "Oregon", defaultValue, true));
states.Add(newItem("PA", "Pennsylvania", defaultValue, true));
states.Add(newItem("RI", "Rhode Island", defaultValue, true));
states.Add(newItem("SC", "South Carolina", defaultValue, true));
states.Add(newItem("SD", "South Dakota", defaultValue, true));
states.Add(newItem("TN", "Tennessee", defaultValue, true));
states.Add(newItem("TX", "Texas", defaultValue, true));
states.Add(newItem("UT", "Utah", defaultValue, true));
states.Add(newItem("VT", "Vermont", defaultValue, true));
states.Add(newItem("VA", "Virginia", defaultValue, true));
states.Add(newItem("WA", "Washington", defaultValue, true));
states.Add(newItem("WV", "West Virginia", defaultValue, true));
states.Add(newItem("WI", "Wisconsin", defaultValue, true));
states.Add(newItem("WY", "Wyoming", defaultValue, true));
foreach (SelectListItem state in states)
{
if (state.Selected)
{
chosen = state;
break;
}
}
}
catch (Exception err)
{
string ss = "ERR! " + err.Source + " " + err.GetType().ToString() + "\r\n" + err.Message.Replace("\r\n", " ");
ss = this.sendError("Online getStateList Request", ss, _errPassword);
// return error
}
// .AsEnumerable() is not required in the pass.. it is an extension of Linq
SelectList myList = new SelectList(states.AsEnumerable(), "Value", "Text", chosen);
object val = myList.SelectedValue;
return myList;
}
public ActionResult pickState(MyModel pData)
{
if (pData.StateList == null)
{
if (String.IsNullOrEmpty(pData.StatePick)) // state abbrev, value collected onchange
{
pData.StateList = getStateList();
}
else
{
pData.StateList = getStateList(pData.StatePick);
}
// assign values to state list items
try
{
SelectListItem si = (SelectListItem)pData.StateList.SelectedValue;
pData.state = si.Value;
pData.StatePick = si.Value;
}
catch { }
}
return View(pData);
}
}
pickState.cshtml...
@model MyProject.Models.MyModel
@{
ViewBag.Title = "United States of America";
Layout = "~/Views/Shared/_Layout.cshtml";
}
<h2>@ViewBag.Title - Where are you...</h2>
@using (Html.BeginForm()) {
@Html.AntiForgeryToken()
@Html.ValidationSummary(true)
<fieldset>
<div class="editor-label">
@Html.DisplayNameFor(model => model.state)
</div>
<div class="display-field">
@Html.DropDownListFor(m => m.StatePick, Model.StateList, new { OnChange = "state.value = this.value;" })
@Html.EditorFor(model => model.state)
@Html.ValidationMessageFor(model => model.StateList)
</div>
</fieldset>
}
<div>
@Html.ActionLink("Back to List", "Index")
</div>