ASP.NET MVC 复选框组

本文介绍了ASP.NET MVC 复选框组的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我正在尝试针对 ASP.NET MVC 中缺少复选框组"的问题制定解决方法.实现这一点的典型方法是使用相同名称的复选框，每个复选框都有它所代表的值.

I am trying to formulate a work-around for the lack of a "checkbox group" in ASP.NET MVC. The typical way to implement this is to have check boxes of the same name, each with the value it represents.

<input type="checkbox" name="n" value=1 /> <input type="checkbox" name="n" value=2 /> <input type="checkbox" name="n" value=3 />

提交时，它将以逗号分隔请求项n"的所有值..因此，如果提交时所有三个都被选中，则请求[n"] ==1,2,3".在 ASP.NET MVC 中，你可以有一个参数 n 作为一个数组来接受这个帖子.

When submitted, it will comma delimit all values to the request item "n".. so Request["n"] == "1,2,3" if all three are checked when submitted. In ASP.NET MVC, you can have a parameter of n as an array to accept this post.

public ActionResult ActionName( int[] n ) { ... }

以上所有工作都正常.我遇到的问题是，当验证失败时，复选框不会恢复到选中状态.任何建议.

All of the above works fine. The problem I have is that when validation fails, the check boxes are not restored to their checked state. Any suggestions.

问题代码:(我从默认的asp mvc项目开始)

Problem Code: (I started with the default asp mvc project)

控制器

public class HomeController : Controller { public ActionResult Index() { var t = getTestModel("First"); return View(t); } [AcceptVerbs(HttpVerbs.Post)] public ActionResult Index(TestModelView t) { if(String.IsNullOrEmpty( t.TextBoxValue)) ModelState.AddModelError("TextBoxValue", "TextBoxValue required."); var newView = getTestModel("Next"); return View(newView); } private TestModelView getTestModel(string prefix) { var t = new TestModelView(); t.Checkboxes = new List<CheckboxInfo>() { new CheckboxInfo(){Text = prefix + "1", Value="1", IsChecked=false}, new CheckboxInfo(){Text = prefix + "2", Value="2", IsChecked=false} }; return t; } } public class TestModelView { public string TextBoxValue { get; set; } public List<CheckboxInfo> Checkboxes { get; set; } } public class CheckboxInfo { public string Text { get; set; } public string Value { get; set; } public bool IsChecked { get; set; } } }

ASPX

<% using( Html.BeginForm() ){ %> <p><%= Html.ValidationSummary() %></p> <p><%= Html.TextBox("TextBoxValue")%></p> <p><% int i = 0; foreach (var cb in Model.Checkboxes) { %> <input type="checkbox" name="Checkboxes[<%=i%>]" value="<%= Html.Encode(cb.Value) %>" <%=cb.IsChecked ? "checked="checked"" : String.Empty %> /><%= Html.Encode(cb.Text)%><br /> <% i++; } %></p> <p><input type="submit" value="submit" /></p> <% } %>

工作代码

控制器

[AcceptVerbs(HttpVerbs.Post)] public ActionResult Index(TestModelView t) { if(String.IsNullOrEmpty( t.TextBoxValue)) { ModelState.AddModelError("TextBoxValue", "TextBoxValue required."); return View(t); } var newView = getTestModel("Next"); return View(newView); }

ASPX

int i = 0; foreach (var cb in Model.Checkboxes) { %> <input type="checkbox" name="Checkboxes[<%=i%>].IsChecked" <%=cb.IsChecked ? "checked="checked"" : String.Empty %> value="true" /> <input type="hidden" name="Checkboxes[<%=i%>].IsChecked" value="false" /> <input type="hidden" name="Checkboxes[<%=i%>].Value" value="<%= cb.Value %>" /> <input type="hidden" name="Checkboxes[<%=i%>].Text" value="<%= cb.Text %>" /> <%= Html.Encode(cb.Text)%><br /> <% i++; } %></p> <p><input type="submit" value="submit" /></p>

当然可以用 Html Helpers 做类似的事情，但这是有效的.

Of course something similar could be done with Html Helpers, but this works.

推荐答案

我不知道如何解决您的问题，但您可以使用以下代码定义复选框:

I don't know how to solve your problem, but you could define your checkboxes with this code:

<%= Html.CheckBox("n[0]") %><%= Html.Hidden("n[0]",false) %> <%= Html.CheckBox("n[1]") %><%= Html.Hidden("n[1]",false) %> <%= Html.CheckBox("n[2]") %><%= Html.Hidden("n[2]",false) %>

需要隐藏字段，因为如果未选中复选框，则表单不会发送任何值.使用隐藏字段发送错误.

Hidden fields are needed, because if checkbox is not checked, form doesn't send any value. With hidden field it sends false.

您的发布方法将是:

[HttpPost] public ActionResult Test(bool[] n) { return View(); }

它可能不是最佳的，我愿意接受评论，但它有效:)

It may not be optimal and I am open to comments, but it works:)

编辑

扩展版:

<%= Html.CheckBox("n[0].Checked") %><%= Html.Hidden("n[0].Value",32) %><%= Html.Hidden("n[0].Checked",false) %> <%= Html.CheckBox("n[1].Checked") %><%= Html.Hidden("n[1].Value",55) %><%= Html.Hidden("n[1].Checked",false) %> <%= Html.CheckBox("n[2].Checked") %><%= Html.Hidden("n[2].Value",76) %><%= Html.Hidden("n[2].Checked",false) %>

您的发布方法将是:

[HttpPost] public ActionResult Test(CheckedValue[] n) { return View(); } public class CheckedValue { public bool Checked { get; set; } public bool Value { get; set; } }

我在没有 VS 的情况下写的，所以可能需要一点点修正.

I wrote it without VS, so it may need little correction.