c# - 如何在 MVC 中为国家和州/省创建选择列表

Question

嗨，我是 MVC 的新手，甚至是 asp ..

我想在 MVC 中创建一个表单。在一些示例的帮助下，我能够创建文本框，但我现在不明白如何创建选择列表。/

我尝试搜索许多在 MVC 中实现 Select List 的示例，但我无法理解。

我有一个表单，它一半用 HTML 编码，一半用 MVC 编码。

这是我的代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace MedAvail.Applications.MedProvision.Web.Models
{
    public class AddressViewModel
    {
        public string Street1 { get; set; }
        public string Street2 { get; set; }
        public string City { get; set; }
        public string Province { get; set; }
        public string Country { get; set; }
        public string PostalCode { get; set; }
        public string PhoneNumber { get; set; }
    }
}




<form id="locationInfo">
    <h1>Location Information</h1>
    <table width="80%" id="locInfo">
        <colgroup>
            <col width="20%" />
            <col />
        </colgroup>
        <tr>
            <th>@Html.Label("Country")</th>
            <td>
                <select required="">
                    <option>Select Country</option>
                    <option>Canada</option>
                    <option>United States</option>
                </select>
                <span class="required">*</span>
            </td>
        </tr>
        <tr>
            <th>@Html.LabelFor(x=>x.State)</th>
            <td>
                <select required="">
                    <option>Select State</option>
                    <option>State 1</option>
                    <option>State 2</option>
                    <option>State 3</option>
                        ...............
                </select><span class="required">*</span></td>
        </tr>
        <tr>
            <th>@Html.LabelFor(x=>x.PostalCode)</th>
            <td>@Html.TextBoxFor(x=>x.PostalCode)<span class="required">*</span></td>
        </tr>
        <tr>
            <th>@Html.LabelFor(x=>x.City)</th>
            <td>@Html.TextBoxFor(x=>x.City)<span class="required">*</span></td>
        </tr>

        <tr>
            <th>@Html.LabelFor(x=>x.StreetAddress1)</th>
            <td>@Html.TextBoxFor(x=>x.StreetAddress1)<span class="required">*</span></td>
        </tr>
        <tr>
            <th>@Html.LabelFor(x=>x.StreetAddress2)</th>
            <td>@Html.TextBoxFor(x=>x.StreetAddress2)</td>
        </tr>
        <tr>
            <th>@Html.LabelFor(x=>x.PhoneNumber)</th>
            <td>@Html.TextBoxFor(x=>x.PhoneNumber)</td>
        </tr>

    </table>


    <div role="button" class="marginTop50 marginBottom">
        <input type="button" id="step3Back" value="Back" class="active" />
        <input type="button" id="step3confirmNext" value="Next" class="active marginLeft50" />
    </div>
</form>

请指导我如何为这种表格创建选择列表。

Answer 1

public static List<SelectListItem> States = new List<SelectListItem>()
    {
        new SelectListItem() {Text="Alabama", Value="AL"},
        new SelectListItem() { Text="Alaska", Value="AK"},
        new SelectListItem() { Text="Arizona", Value="AZ"},
        new SelectListItem() { Text="Arkansas", Value="AR"},
        new SelectListItem() { Text="California", Value="CA"},
        new SelectListItem() { Text="Colorado", Value="CO"},
        new SelectListItem() { Text="Connecticut", Value="CT"},
        new SelectListItem() { Text="District of Columbia", Value="DC"},
        new SelectListItem() { Text="Delaware", Value="DE"},
        new SelectListItem() { Text="Florida", Value="FL"},
        new SelectListItem() { Text="Georgia", Value="GA"},
        new SelectListItem() { Text="Hawaii", Value="HI"},
        new SelectListItem() { Text="Idaho", Value="ID"},
        new SelectListItem() { Text="Illinois", Value="IL"},
        new SelectListItem() { Text="Indiana", Value="IN"},
        new SelectListItem() { Text="Iowa", Value="IA"},
        new SelectListItem() { Text="Kansas", Value="KS"},
        new SelectListItem() { Text="Kentucky", Value="KY"},
        new SelectListItem() { Text="Louisiana", Value="LA"},
        new SelectListItem() { Text="Maine", Value="ME"},
        new SelectListItem() { Text="Maryland", Value="MD"},
        new SelectListItem() { Text="Massachusetts", Value="MA"},
        new SelectListItem() { Text="Michigan", Value="MI"},
        new SelectListItem() { Text="Minnesota", Value="MN"},
        new SelectListItem() { Text="Mississippi", Value="MS"},
        new SelectListItem() { Text="Missouri", Value="MO"},
        new SelectListItem() { Text="Montana", Value="MT"},
        new SelectListItem() { Text="Nebraska", Value="NE"},
        new SelectListItem() { Text="Nevada", Value="NV"},
        new SelectListItem() { Text="New Hampshire", Value="NH"},
        new SelectListItem() { Text="New Jersey", Value="NJ"},
        new SelectListItem() { Text="New Mexico", Value="NM"},
        new SelectListItem() { Text="New York", Value="NY"},
        new SelectListItem() { Text="North Carolina", Value="NC"},
        new SelectListItem() { Text="North Dakota", Value="ND"},
        new SelectListItem() { Text="Ohio", Value="OH"},
        new SelectListItem() { Text="Oklahoma", Value="OK"},
        new SelectListItem() { Text="Oregon", Value="OR"},
        new SelectListItem() { Text="Pennsylvania", Value="PA"},
        new SelectListItem() { Text="Rhode Island", Value="RI"},
        new SelectListItem() { Text="South Carolina", Value="SC"},
        new SelectListItem() { Text="South Dakota", Value="SD"},
        new SelectListItem() { Text="Tennessee", Value="TN"},
        new SelectListItem() { Text="Texas", Value="TX"},
        new SelectListItem() { Text="Utah", Value="UT"},
        new SelectListItem() { Text="Vermont", Value="VT"},
        new SelectListItem() { Text="Virginia", Value="VA"},
        new SelectListItem() { Text="Washington", Value="WA"},
        new SelectListItem() { Text="West Virginia", Value="WV"},
        new SelectListItem() { Text="Wisconsin", Value="WI"},
        new SelectListItem() { Text="Wyoming", Value="WY"}
    };

我们是怎么做的，就是把这个方法放到一个类中，然后从视图中调用这个类

@Html.DropDownListFor(x => x.State, Class.States)

Answer 2

谢谢你们！我现在可以根据 MVC 加载选择列表我的工作代码如下：

视图中的 HTML+MVC 代码：-

    <tr>
        <th>@Html.Label("Country")</th>
        <td>@Html.DropDownListFor(x =>x.Province,SelectListItemHelper.GetCountryList())<span class="required">*</span></td>
    </tr>
    <tr>
        <th>@Html.LabelFor(x=>x.Province)</th>
        <td>@Html.DropDownListFor(x =>x.Province,SelectListItemHelper.GetProvincesList())<span class="required">*</span></td>
    </tr>

在“UTIL”文件夹下创建了一个控制器：代码：-

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;

namespace MedAvail.Applications.MedProvision.Web.Util
{
    public class SelectListItemHelper
    {
        public static IEnumerable<SelectListItem> GetProvincesList()
        {
            IList<SelectListItem> items = new List<SelectListItem>
            {
                new SelectListItem{Text = "California", Value = "B"},
                new SelectListItem{Text = "Alaska", Value = "B"},
                new SelectListItem{Text = "Illinois", Value = "B"},
                new SelectListItem{Text = "Texas", Value = "B"},
                new SelectListItem{Text = "Washington", Value = "B"}

            };
            return items;
        }


        public static IEnumerable<SelectListItem> GetCountryList()
        {
            IList<SelectListItem> items = new List<SelectListItem>
            {
                new SelectListItem{Text = "United States", Value = "B"},
                new SelectListItem{Text = "Canada", Value = "B"},
                new SelectListItem{Text = "United Kingdom", Value = "B"},
                new SelectListItem{Text = "Texas", Value = "B"},
                new SelectListItem{Text = "Washington", Value = "B"}

            };
            return items;
        }


    }
}

现在它的工作很酷:-)

谢谢！！

Answer 3

这次真是万分感谢

这是我所做的：

1.在 Utils 文件夹中创建 Extensions.cs 文件。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;

namespace Web.ProjectName.Utils
{
    public class Extensions
    {
        public static IEnumerable<SelectListItem> GetStatesList()
        {
            IList<SelectListItem> states = new List<SelectListItem>
            {
                new SelectListItem() {Text="Alabama", Value="AL"},
                new SelectListItem() { Text="Alaska", Value="AK"},
                new SelectListItem() { Text="Arizona", Value="AZ"},
                new SelectListItem() { Text="Arkansas", Value="AR"},
                new SelectListItem() { Text="California", Value="CA"},
                new SelectListItem() { Text="Colorado", Value="CO"},
                new SelectListItem() { Text="Connecticut", Value="CT"},
                new SelectListItem() { Text="District of Columbia", Value="DC"},
                new SelectListItem() { Text="Delaware", Value="DE"},
                new SelectListItem() { Text="Florida", Value="FL"},
                new SelectListItem() { Text="Georgia", Value="GA"},
                new SelectListItem() { Text="Hawaii", Value="HI"},
                new SelectListItem() { Text="Idaho", Value="ID"},
                new SelectListItem() { Text="Illinois", Value="IL"},
                new SelectListItem() { Text="Indiana", Value="IN"},
                new SelectListItem() { Text="Iowa", Value="IA"},
                new SelectListItem() { Text="Kansas", Value="KS"},
                new SelectListItem() { Text="Kentucky", Value="KY"},
                new SelectListItem() { Text="Louisiana", Value="LA"},
                new SelectListItem() { Text="Maine", Value="ME"},
                new SelectListItem() { Text="Maryland", Value="MD"},
                new SelectListItem() { Text="Massachusetts", Value="MA"},
                new SelectListItem() { Text="Michigan", Value="MI"},
                new SelectListItem() { Text="Minnesota", Value="MN"},
                new SelectListItem() { Text="Mississippi", Value="MS"},
                new SelectListItem() { Text="Missouri", Value="MO"},
                new SelectListItem() { Text="Montana", Value="MT"},
                new SelectListItem() { Text="Nebraska", Value="NE"},
                new SelectListItem() { Text="Nevada", Value="NV"},
                new SelectListItem() { Text="New Hampshire", Value="NH"},
                new SelectListItem() { Text="New Jersey", Value="NJ"},
                new SelectListItem() { Text="New Mexico", Value="NM"},
                new SelectListItem() { Text="New York", Value="NY"},
                new SelectListItem() { Text="North Carolina", Value="NC"},
                new SelectListItem() { Text="North Dakota", Value="ND"},
                new SelectListItem() { Text="Ohio", Value="OH"},
                new SelectListItem() { Text="Oklahoma", Value="OK"},
                new SelectListItem() { Text="Oregon", Value="OR"},
                new SelectListItem() { Text="Pennsylvania", Value="PA"},
                new SelectListItem() { Text="Rhode Island", Value="RI"},
                new SelectListItem() { Text="South Carolina", Value="SC"},
                new SelectListItem() { Text="South Dakota", Value="SD"},
                new SelectListItem() { Text="Tennessee", Value="TN"},
                new SelectListItem() { Text="Texas", Value="TX"},
                new SelectListItem() { Text="Utah", Value="UT"},
                new SelectListItem() { Text="Vermont", Value="VT"},
                new SelectListItem() { Text="Virginia", Value="VA"},
                new SelectListItem() { Text="Washington", Value="WA"},
                new SelectListItem() { Text="West Virginia", Value="WV"},
                new SelectListItem() { Text="Wisconsin", Value="WI"},
                new SelectListItem() { Text="Wyoming", Value="WY"}
            };
            return states;
        }
    }
}

2.在我的模型中，状态将被缩写（例如“AL”、“NY”等）：

using System.ComponentModel;
using System.ComponentModel.DataAnnotations;

namespace Web.ProjectName.Models
{
    public class ContactForm
    {

        ...

        [Required]
        [Display(Name = "State")]
        [RegularExpression("[A-Z]{2}")]
        public string State { get; set; }

        ...

    }
}

2.在我看来，我引用了它：

  @model Web.ProjectName.Models.ContactForm

  ...

  @Html.LabelFor(x => x.State, new { @class = "form-label" })
  @Html.DropDownListFor(x => x.State, Web.ProjectName.Utils.Extensions.GetStatesList(), new { @class = "form-control" })

  ...

Answer 4

设计你的模型：

Public class ModelName
{
    ...// Properties
    public IEnumerable<SelectListItem> ListName { get; set; }
}

准备 List 并将其绑定到 Controller 中的模型：

    public ActionResult Index(ModelName model)
    {
        var items = // Your List of data
        model.ListName = items.Select(x=> new SelectListItem() {
                    Text = x.prop,
                    Value = x.prop2
               });
    }

在你看来：

@Html.DropDownListFor(m => Model.prop2,Model.ListName)

Answer 5

有很多方法可以做到这一点......对于#NetCore 使用 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;

模型...

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; }
  }
}

控制器...

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);
    }
}

选择状态.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>

Answer 6

我也很喜欢乔丹的回答并自己实施。我只需要缩写，以防其他人需要相同的：

    public static IEnumerable<SelectListItem> GetStatesList()
    {
        IList<SelectListItem> states = new List<SelectListItem>
        {
            new SelectListItem() {Text="AL", Value="AL"},
            new SelectListItem() { Text="AK", Value="AK"},
            new SelectListItem() { Text="AZ", Value="AZ"},
            new SelectListItem() { Text="AR", Value="AR"},
            new SelectListItem() { Text="CA", Value="CA"},
            new SelectListItem() { Text="CO", Value="CO"},
            new SelectListItem() { Text="CT", Value="CT"},
            new SelectListItem() { Text="DC", Value="DC"},
            new SelectListItem() { Text="DE", Value="DE"},
            new SelectListItem() { Text="FL", Value="FL"},
            new SelectListItem() { Text="GA", Value="GA"},
            new SelectListItem() { Text="HI", Value="HI"},
            new SelectListItem() { Text="ID", Value="ID"},
            new SelectListItem() { Text="IL", Value="IL"},
            new SelectListItem() { Text="IN", Value="IN"},
            new SelectListItem() { Text="IA", Value="IA"},
            new SelectListItem() { Text="KS", Value="KS"},
            new SelectListItem() { Text="KY", Value="KY"},
            new SelectListItem() { Text="LA", Value="LA"},
            new SelectListItem() { Text="ME", Value="ME"},
            new SelectListItem() { Text="MD", Value="MD"},
            new SelectListItem() { Text="MA", Value="MA"},
            new SelectListItem() { Text="MI", Value="MI"},
            new SelectListItem() { Text="MN", Value="MN"},
            new SelectListItem() { Text="MS", Value="MS"},
            new SelectListItem() { Text="MO", Value="MO"},
            new SelectListItem() { Text="MT", Value="MT"},
            new SelectListItem() { Text="NE", Value="NE"},
            new SelectListItem() { Text="NV", Value="NV"},
            new SelectListItem() { Text="NH", Value="NH"},
            new SelectListItem() { Text="NJ", Value="NJ"},
            new SelectListItem() { Text="NM", Value="NM"},
            new SelectListItem() { Text="NY", Value="NY"},
            new SelectListItem() { Text="NC", Value="NC"},
            new SelectListItem() { Text="ND", Value="ND"},
            new SelectListItem() { Text="OH", Value="OH"},
            new SelectListItem() { Text="OK", Value="OK"},
            new SelectListItem() { Text="OR", Value="OR"},
            new SelectListItem() { Text="PA", Value="PA"},
            new SelectListItem() { Text="PR", Value="PR"},
            new SelectListItem() { Text="RI", Value="RI"},
            new SelectListItem() { Text="SC", Value="SC"},
            new SelectListItem() { Text="SD", Value="SD"},
            new SelectListItem() { Text="TN", Value="TN"},
            new SelectListItem() { Text="TX", Value="TX"},
            new SelectListItem() { Text="UT", Value="UT"},
            new SelectListItem() { Text="VT", Value="VT"},
            new SelectListItem() { Text="VA", Value="VA"},
            new SelectListItem() { Text="WA", Value="WA"},
            new SelectListItem() { Text="WV", Value="WV"},
            new SelectListItem() { Text="WI", Value="WI"},
            new SelectListItem() { Text="WY", Value="WY"}
        };
        return states;
    }

Answer 7

制作下拉列表的最佳方法：

grid.Column("PriceType",canSort:true,header: "PriceType",format: @<span>
    <span id="spanPriceType_@item.ShoppingCartID">@item.PriceTypeDescription</span>
    @Html.DropDownList("PriceType"+(int)item.ShoppingCartID,new SelectList(MvcApplication1.Services.ExigoApiContext.CreateODataContext().PriceTypes.Select(s => new { s.PriceTypeID, s.PriceTypeDescription }).AsEnumerable(),"PriceTypeID", "PriceTypeDescription",Convert.ToInt32(item.PriceTypeId)), new { @class = "PriceType",@style="width:120px;display:none",@selectedvalue="selected"})
        </span>),