How to Set RadioButtonFor() in ASp.net MVC 2 as Checked by default

问题

How can i Set RadioButtonFor() as Checked By Default

<%=Html.RadioButtonFor(m => m.Gender,"Male")%>

there is way out for (Html.RadioButton) but not for (Html.RadioButtonFor)

any Ideas?

回答1:

This question on StackOverflow deals with RadioButtonListFor and the answer addresses your question too. You can set the selected property in the RadioButtonListViewModel.

回答2:

Use the simple way:

<%= Html.RadioButtonFor(m => m.Gender, "Male", new { Checked = "checked" })%>

回答3:

It's not too pretty, but if you have to implement only very few radio buttons for the entire site, something like this might also be an option:

<%=Html.RadioButtonFor(m => m.Gender,"Male",Model.Gender=="Male" ? new { @checked = "checked" } : null)%>

回答4:

I assume you should have a group of radio buttons. something could be like

<%=Html.RadioButtonFor(m => m.Gender,"Male")%>
<%=Html.RadioButtonFor(m => m.Gender,"Female")%>
<%=Html.RadioButtonFor(m => m.Gender,"Unknown")%>

You may give the default value for m.Gender = "Unknown" (or something) from your controller.

回答5:

This Helper evaluates the expression and if equals to the value it checks the radio button, and has the same parameters than RadioButtonFor (for this reason the name is diferent):

public static MvcHtmlString CheckedRadioButtonFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, object value)
{
    return CheckedRadioButtonFor(htmlHelper, expression, value, null);
}

public static MvcHtmlString CheckedRadioButtonFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, object value, object htmlAttributes)
{
    var func = expression.Compile();
    var attributes = new RouteValueDictionary(htmlAttributes);
    if ((object)func(htmlHelper.ViewData.Model) == value) {
        attributes["checked"] = "checked";
    }
    return htmlHelper.RadioButtonFor(expression, value, attributes);
}

Usage:

<%= Html.CheckedRadioButtonFor(m => m.Gender, "Male", new { id = "gender-male" })%>

Result:

<!-- For Model.Gender = "Male" -->
<input checked="checked" id="gender-male" name="Gender" type="radio" value="Male">
<!-- For Model.Gender = "Female" -->
<input id="gender-male" name="Gender" type="radio" value="Male">

回答6:

I found another option so you can just use @Html.EditorFor() with templates:

Say I have this enum:

public enum EmailType { Pdf, Html }

I can put this code in Views/Shared/EditorTemplates/EmailType.cshtml

@model EmailType
@{
    var htmlOptions = Model == EmailType.Html ? new { @checked = "checked" } : null;
    var pdfOptions = Model == EmailType.Pdf ? new { @checked = "checked" } : null;
}

@Html.RadioButtonFor(x => x, EmailType.Html, htmlOptions) @EmailType.Html.ToString()
@Html.RadioButtonFor(x => x, EmailType.Pdf, pdfOptions) @EmailType.Pdf.ToString()

Now I can simply use this if I want to use it at any time:

@Html.EditorFor(x => x.EmailType)

It's much more universal this way, and easier to change I feel.

回答7:

You can also add labels that are tied to your radio buttons with the same ID, which then allows the user to click the radio button or label to select that item. I'm using constants here for "Male", "Female" and "Unknown", but obviously these could be strings in your model.

<%: Html.RadioButtonFor(m => m.Gender, "Male", 
    new Dictionary<string, object> { { "checked", "checked" }, { "id", "Male" } }) %>
<%: Html.Label("Male") %>

<%: Html.RadioButtonFor(m => m.Gender, "Female", 
    new Dictionary<string, object> { { "id", "Female" } }) %>
<%: Html.Label("Female")%>

<%: Html.RadioButtonFor(m => m.Gender, "Unknown",
    new Dictionary<string, object> { { "id", "Unknown" } }) %>
<%: Html.Label("Unknown")%>

回答8:

<%: Html.RadioButtonFor(m => m.Gender, "Male", new { @checked = true } )%>

or

@checked = checked

if you like

回答9:

Came across this and thought I would point out that for MVC 5 all you need to do is set the value on the model. For Example:

Model:

   public class ExampleModel
    {
        public PackingListInputModel()
        {

             RadioButtonField = "One";

        }
        public string RadioButtonField { get; set; }
    }

View :

@model ExampleModel

@using (Html.BeginForm)
{
    @Html.RadioButtonFor(m => m.RadioButtonField , "One")
    @Html.RadioButtonFor(m => m.RadioButtonField , "Two")
}

The state of the first radio button ("One") will be set as active because the value matches what was set in the model.

回答10:

If you're using jquery, you can call this right before your radio buttons.

$('input:radio:first').attr('checked', true);

^ This will check the first radio box, but you can look at more jquery to cycle through to the one you want selected.

回答11:

           @Html.RadioButton("Insured.GenderType", 1, (Model.Insured.GenderType == 1 ))
           @Web.Mvc.Claims.Resources.PartyResource.MaleLabel
           @Html.RadioButton("Insured.GenderType", 2, Model.Insured.GenderType == 2)
           @Web.Mvc.Claims.Resources.PartyResource.FemaleLabel

回答12:

Here is code to set default radio button set to true

@Html.RadioButtonFor(m => m.Gender, "Male", new { @checked = "checked", id = "rdGender", name = "rbGender" })

回答13:

I find it best to just put the default value in the constructor method of the model.

Gender = "Male";

回答14:

You need to add 'checked' htmlAttribute in RadioButtonFor, if the radiobutton's value matches with Model.Gender value.

@{
        foreach (var item in Model.GenderList)
        {
            <div class="btn-group" role="group">
               <label class="btn btn-default">
                   @Html.RadioButtonFor(m => m.Gender, item.Key, (int)Model.Gender==item.Key ? new { @checked = "checked" } : null)
                   @item.Value
              </label>
            </div>
        }
    }

For complete code see below link: To render bootstrap radio button group with default checked. stackoverflow answer link

来源：https://stackoverflow.com/questions/2598668/how-to-set-radiobuttonfor-in-asp-net-mvc-2-as-checked-by-default