如何使用Html.CheckBox(列表)与IEnumerable的与验证
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28-09-2019 - |
题
我正在一个页面,用户需要填写一些信息,并最终做出选择1个或多个客户提供的复选框上。
客户的列表是我传递到我的模型的IEnumerable<Customer>
。我怎么会去有关创建的使用.CheckBoxFor()
的复选框列表?
最后,我想能够验证是否已选择的至少1复选框。
请求是保持用户输入的信息的对象。
<% foreach (var customer in Model.Request.Customers) { %>
<%= Html.CheckBoxFor(/* customer */) %>
<% } %>
任何人都可以点我在正确的方向?还是我这一切错了吗?
解决方案
您可以创建定制的HTML扩展类和重载CheckBoxFor方法等下方。该方法评估的metadata.Model到传递给它(如美国的国家)的值。你可以得到该复选框值从ControllerAction中的FormCollection / S:
public ActionResult Edit(FormCollection formCollection)
{
// Get the value(s)
string checkBox = formCollection["State"];
// perform validation
....
}
实施例假定keyvaluepair通用的列表
<% foreach (var element in UnitedStatesDictionary())
{ %>
<%= Html.CheckBoxFor(model => model.State, null, element.Key) %><%= element.Value %><br />
<% } %>
HtmlExtensions.cs
using System;
using System.Linq;
using System.Linq.Expressions;
using System.Web.Mvc;
using System.Web.Routing;
public static class HtmlExtensions
{
/// <summary>
/// Checks the box for.
/// </summary>
/// <typeparam name="TModel">The type of the model.</typeparam>
/// <typeparam name="TValue">The type of the value.</typeparam>
/// <param name="html">The HTML.</param>
/// <param name="expression">The expression.</param>
/// <returns>Checkbox</returns>
public static MvcHtmlString CheckBoxFor<TModel, TValue>(this HtmlHelper<TModel> html, Expression<Func<TModel, TValue>> expression)
{
return CheckBoxFor(html, expression, new RouteDirection());
}
/// <summary>
/// Checks the box for.
/// </summary>
/// <typeparam name="TModel">The type of the model.</typeparam>
/// <typeparam name="TValue">The type of the value.</typeparam>
/// <param name="html">The HTML.</param>
/// <param name="expression">The expression.</param>
/// <param name="htmlAttributes">The HTML attributes.</param>
/// <returns>Checkbox</returns>
public static MvcHtmlString CheckBoxFor<TModel, TValue>(this HtmlHelper<TModel> html, Expression<Func<TModel, TValue>> expression, object htmlAttributes)
{
return CheckBoxFor(html, expression, htmlAttributes, "");
}
/// <summary>
/// Checks the box for.
/// </summary>
/// <typeparam name="TModel">The type of the model.</typeparam>
/// <typeparam name="TValue">The type of the value.</typeparam>
/// <param name="html">The HTML.</param>
/// <param name="expression">The expression.</param>
/// <param name="htmlAttributes">The HTML attributes.</param>
/// <param name="checkedValue">The checked value.</param>
/// <returns>Checkbox</returns>
public static MvcHtmlString CheckBoxFor<TModel, TValue>(this HtmlHelper<TModel> html, Expression<Func<TModel, TValue>> expression, object htmlAttributes, string checkedValue)
{
ModelMetadata metadata = ModelMetadata.FromLambdaExpression(expression, html.ViewData);
string htmlFieldName = ExpressionHelper.GetExpressionText(expression);
TagBuilder tag = new TagBuilder("input");
tag.Attributes.Add("type", "checkbox");
tag.Attributes.Add("name", metadata.PropertyName);
if (!string.IsNullOrEmpty(checkedValue))
{
tag.Attributes.Add("value", checkedValue);
}
else
{
tag.Attributes.Add("value", metadata.Model.ToString());
}
if (htmlAttributes != null)
{
tag.MergeAttributes(new RouteValueDictionary(htmlAttributes));
}
if (metadata.Model.ToString() == checkedValue)
{
tag.Attributes.Add("checked", "checked");
}
return MvcHtmlString.Create(tag.ToString(TagRenderMode.SelfClosing));
}
}
而我在这,这里是我的美国,以完整的代码清单:
/// <summary>
/// United States dictionary.
/// </summary>
/// <returns>List of United States</returns>
public static List<KeyValuePair<string, string>> UnitedStatesDictionary()
{
var arrList = new List<KeyValuePair<string, string>>();
arrList.Add(new KeyValuePair<string, string>("AL", "Alabama"));
arrList.Add(new KeyValuePair<string, string>("AK", "Alaska"));
arrList.Add(new KeyValuePair<string, string>("AZ", "Arizona" ));
arrList.Add(new KeyValuePair<string, string>("AR", "Arkansas" ));
arrList.Add(new KeyValuePair<string, string>("CA", "California" ));
arrList.Add(new KeyValuePair<string, string>("CO", "Colorado" ));
arrList.Add(new KeyValuePair<string, string>("CT", "Connecticut" ));
arrList.Add(new KeyValuePair<string, string>("DE", "Delaware" ));
arrList.Add(new KeyValuePair<string, string>("DC", "District Of Columbia" ));
arrList.Add(new KeyValuePair<string, string>("FL", "Florida" ));
arrList.Add(new KeyValuePair<string, string>("GA", "Georgia" ));
arrList.Add(new KeyValuePair<string, string>("HI", "Hawaii" ));
arrList.Add(new KeyValuePair<string, string>("ID", "Idaho" ));
arrList.Add(new KeyValuePair<string, string>("IL", "Illinois" ));
arrList.Add(new KeyValuePair<string, string>("IN", "Indiana" ));
arrList.Add(new KeyValuePair<string, string>("IA", "Iowa" ));
arrList.Add(new KeyValuePair<string, string>("KS", "Kansas" ));
arrList.Add(new KeyValuePair<string, string>("KY", "Kentucky" ));
arrList.Add(new KeyValuePair<string, string>("LA", "Louisiana" ));
arrList.Add(new KeyValuePair<string, string>("ME", "Maine" ));
arrList.Add(new KeyValuePair<string, string>("MD", "Maryland" ));
arrList.Add(new KeyValuePair<string, string>("MA", "Massachusetts" ));
arrList.Add(new KeyValuePair<string, string>("MI", "Michigan" ));
arrList.Add(new KeyValuePair<string, string>("MN", "Minnesota" ));
arrList.Add(new KeyValuePair<string, string>("MS", "Mississippi" ));
arrList.Add(new KeyValuePair<string, string>("MO", "Missouri" ));
arrList.Add(new KeyValuePair<string, string>("MT", "Montana" ));
arrList.Add(new KeyValuePair<string, string>("NE", "Nebraska" ));
arrList.Add(new KeyValuePair<string, string>("NV", "Nevada" ));
arrList.Add(new KeyValuePair<string, string>("NH", "New Hampshire" ));
arrList.Add(new KeyValuePair<string, string>("NJ", "New Jersey" ));
arrList.Add(new KeyValuePair<string, string>("NM", "New Mexico" ));
arrList.Add(new KeyValuePair<string, string>("NY", "New York" ));
arrList.Add(new KeyValuePair<string, string>("NC", "North Carolina" ));
arrList.Add(new KeyValuePair<string, string>("ND", "North Dakota" ));
arrList.Add(new KeyValuePair<string, string>("OH", "Ohio" ));
arrList.Add(new KeyValuePair<string, string>("OK", "Oklahoma" ));
arrList.Add(new KeyValuePair<string, string>("OR", "Oregon" ));
arrList.Add(new KeyValuePair<string, string>("PA", "Pennsylvania" ));
arrList.Add(new KeyValuePair<string, string>("RI", "Rhode Island" ));
arrList.Add(new KeyValuePair<string, string>("SC", "South Carolina" ));
arrList.Add(new KeyValuePair<string, string>("SD", "South Dakota" ));
arrList.Add(new KeyValuePair<string, string>("TN", "Tennessee" ));
arrList.Add(new KeyValuePair<string, string>("TX", "Texas" ));
arrList.Add(new KeyValuePair<string, string>("UT", "Utah" ));
arrList.Add(new KeyValuePair<string, string>("VT", "Vermont" ));
arrList.Add(new KeyValuePair<string, string>("VA", "Virginia" ));
arrList.Add(new KeyValuePair<string, string>("WA", "Washington" ));
arrList.Add(new KeyValuePair<string, string>("WV", "West Virginia" ));
arrList.Add(new KeyValuePair<string, string>("WI", "Wisconsin" ));
arrList.Add(new KeyValuePair<string, string>("WY", "Wyoming" ));
return arrList;
}
其他提示
Html.CheckBoxFor()扩展方法被设计为修改的布尔类型的模型的特性。你想用它来选择IEnumerable集合某些对象。这是错误的。
右的方式:
鉴于
<form action="/Customer/Process">
<% foreach (var customer in Model.Request.Customers)
{ %>
<input type="checkbox" name="selectedId" value="<%= customer.id %>" />
<%= customer.name %>
<br/>
<% } %>
<input type="submit"/>
</form>
在控制器
public string Process(IEnumerable<Guid> selectedId)
{
if (selectedId == null)
{
ModelState.AddModelError("selectedId", "Have to select at least one customer!");
return View();
}
// do something with customers' ids
}
我用一个辅助类为该。它真的很简单。随着辅助类,你可以使用的SelectList,并把它的帮手,就像你的dropdownfor做。
文件夹 “帮助者” 在我有Checkboxlist.cs
using System;
using System.Web.Mvc;
using System.Collections.Generic;
using System.Text;
using System.Linq;
namespace MVC2_NASTEST.Helpers {
public static class CheckBoxListHelper {
public static string CheckBoxList(this HtmlHelper helper, string name, IDictionary<string, string> items) {
return CheckBoxList(helper, name, items, null, null);
}
public static string CheckBoxList(this HtmlHelper helper, string name, IDictionary<string, string> items, IDictionary<string, object> checkboxHtmlAttributes) {
return CheckBoxList(helper, name, items, null, checkboxHtmlAttributes);
}
public static string CheckBoxList(this HtmlHelper helper, string name, IDictionary<string, string> items, IEnumerable<string> selectedValues) {
return CheckBoxList(helper, name, items, selectedValues, null);
}
public static string CheckBoxList(this HtmlHelper helper, string name, IDictionary<string, string> items, IEnumerable<string> selectedValues, IDictionary<string, object> checkboxHtmlAttributes) {
var selectListItems = from i in items
select new SelectListItem {
Text = i.Key,
Value = i.Value,
Selected = (selectedValues != null && selectedValues.Contains(i.Value))
};
return CheckBoxList(helper, name, selectListItems, checkboxHtmlAttributes);
}
public static string CheckBoxList(this HtmlHelper helper, string name, IEnumerable<SelectListItem> items) {
return CheckBoxList(helper, name, items, null);
}
public static string CheckBoxList(this HtmlHelper helper, string name, IEnumerable<SelectListItem> items, IDictionary<string, object> checkboxHtmlAttributes) {
var output = new StringBuilder();
foreach (var item in items) {
output.Append("<div class=\"fields\"><label>");
var checkboxList = new TagBuilder("input");
checkboxList.MergeAttribute("type", "checkbox");
checkboxList.MergeAttribute("name", name);
checkboxList.MergeAttribute("value", item.Value);
// Check to see if it's checked
if (item.Selected)
checkboxList.MergeAttribute("checked", "checked");
// Add any attributes
if (checkboxHtmlAttributes != null)
checkboxList.MergeAttributes(checkboxHtmlAttributes);
checkboxList.SetInnerText(item.Text);
output.Append(checkboxList.ToString(TagRenderMode.SelfClosing));
output.Append(" " + item.Text + "</label></div>");
}
return output.ToString();
}
}
}
在我的控制器的代码:
public static List<SelectListItem> lesgeverList() {
return lesgeverList(-1);
}
public static List<SelectListItem> lesgeverList(int selectedID) {
return lesgeverList(new int[] { selectedID });
}
public static List<SelectListItem> lesgeverList(int[] lg) {
NASDataContext _db = new NASDataContext();
var lesg = (from l in _db.Lesgevers
where l.LG_Naam != "leeg"
orderby l.LG_Naam, l.LG_Vnaam
select l).ToSelectList(m => m.LG_Naam + " " + m.LG_Vnaam, m => m.LG_ID.ToString(), m => lg.Contains(m.LG_ID));
return lesg.ToList();
}
//
// GET: /Projectleiders/Create
public ActionResult Create(int projID) {
ViewData["projNaam"] = getProject(projID).Proj_Kortenaam;
int[] keys = (from p in _db.ProjectleiderProjectens
where p.Proj_ID == projID
from l in _db.Lesgevers
where p.LG_ID == l.LG_ID
select l.LG_ID).ToArray();
ViewData["projleiders"] = MvcApplication.lesgeverList(keys);
return toegankelijk(projID, null);
}
//
// POST: /Projectleiders/Create
[HttpPost]
public ActionResult Create(FormCollection collection, int projID) {
if (collection["lesgeverlist"] != null) {
string[] lgevers = collection["lesgeverlist"].Split(new string[] { "," }, StringSplitOptions.RemoveEmptyEntries);
List<ProjectleiderProjecten> lst = new List<ProjectleiderProjecten>();
foreach (string s in lgevers) {
ProjectleiderProjecten prl = new ProjectleiderProjecten();
prl.LG_ID = int.Parse(s);
prl.Proj_ID = projID;
int count = (from m in _db.ProjectleiderProjectens
where m.LG_ID == prl.LG_ID && m.Proj_ID == prl.Proj_ID
select m).Count();
if (count <= 0) {
//deze bestaat nog niet
lst.Add(prl);
}
}
//var test = _db.ProjectleiderProjectens.Where(p => p.Proj_ID == projID && !lgevers.Contains(p.LG_ID.ToString())).ToList();
_db.ProjectleiderProjectens.DeleteAllOnSubmit(_db.ProjectleiderProjectens.Where(p => p.Proj_ID == projID && !lgevers.Contains(p.LG_ID.ToString())));
_db.ProjectleiderProjectens.InsertAllOnSubmit(lst);
_db.SubmitChanges();
return RedirectToAction("Index");
} else {
ModelState.AddModelError("lesgeverlist", "Je hebt geen lesgevers geselecteerd");
ViewData["projleiders"] = MvcApplication.lesgeverList();
ViewData["projNaam"] = getProject(projID).Proj_Kortenaam;
return View();
}
}
我用的是ToSelectList扩展,它是每个人都应该有。
public static class VSKOExtensions {
public static IList<SelectListItem> ToSelectList<T>(this IEnumerable<T> itemsToMap, Func<T, string> textProperty, Func<T, string> valueProperty, Predicate<T> isSelected) {
var result = new List<SelectListItem>();
foreach (var item in itemsToMap) {
result.Add(new SelectListItem {
Value = valueProperty(item),
Text = textProperty(item),
Selected = isSelected(item)
});
}
return result;
}
}
在我的创建视图的代码(也就是在同一时间的编辑视图)是很简单的
<%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<MVC2_NASTEST.Models.ProjectleiderProjecten>" %>
<%@ Import Namespace="MVC2_NASTEST.Helpers" %>
<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
Create
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
<h2>Koppel projectleider voor
<%= ViewData["projNaam"].ToString() %></h2>
<% using (Html.BeginForm()) {%>
<%= Html.ValidationSummary(true) %>
<fieldset>
<legend>Fields</legend>
<div class="editor-label">
<%= Html.Label("Lesgevers")%>
</div>
<div class="editor-field">
<%= Html.CheckBoxList("Lesgeverlist", ViewData["projleiders"] as List<SelectListItem>)%>
<%= Html.ValidationMessage("Lesgeverlist")%>
</div>
<p>
<input type="submit" value="Create" />
</p>
</fieldset>
<% } %>
<div>
<%= Html.ActionLink("Back to List", "Index") %>
</div>
</asp:Content>
它如何工作的:
i。从已选择的用户的DB获得的值,得到他们的ID并把它送给所述方法MvcApplication.lesgeverList(键);
然后我得到的选择列表的后面,把它的可视数据,并入选者都在我看来,选择当我打开它。然后当我改变一些箱子和保存它,我检查如果集合心不是空(因此,一些被选中),然后我分裂变量我回来,这是“价值就是你在选择列表的给予。我通过他们的foreach,他们解析到整型,从DB的用户与他们的解析的ID。与计数i看,如果他们在被称为_db.ProjectleiderProjectens的“链接”表中存在或不
当所有的添加,我使用LINQ语句删除所有“未选定的” 1在1次
_db.ProjectleiderProjectens.DeleteAllOnSubmit(_db.ProjectleiderProjectens.Where(p => p.Proj_ID == projID && !lgevers.Contains(p.LG_ID.ToString())));
我认为这是相当可读。删除所有对象,得到所有对象的ID和检查哪些不是字符串中[] ID的
的它工作得相当好,我必须说。如果您有更多的问题,只是问。
只需使用jQuery验证在客户端,然后自己仔细检查服务器端只确保表单收集已经填充了值。
有什么不对您的for循环。