how do radio buttons work with asp.net mvc binding

Question

i have an strongly typed object that represents all of the textbox properties of a form and it works fine when i post to the controller.

i now need to add a radio button to this form. how does that map to the strongly typed objects?

Answer 1

If you use the HtmlHelper.RadioButton you will be fine as long as the name matches your property name.

Below is a snippet of code from one of my projects:

<span><%= Html.RadioButton("DateFormat", "MMMM/dd/yy", Model.DateFormat.Equals("MMMM/dd/yy"), new Dictionary<string, object> { { "class", "normalwidth" } })%><label class="displayinline"><%=DateTime.Now.ToString("MMMM dd, yyyy")%></label></span>
<span><%= Html.RadioButton("DateFormat", "yyyy/MM/dd", Model.DateFormat.Equals("yyyy/MM/dd"), new Dictionary<string, object> { { "class", "normalwidth" } })%><label class="displayinline"><%=DateTime.Now.ToString("yyyy/MM/dd")%></label></span>
<span><%= Html.RadioButton("DateFormat", "dd/MM/yyyy", Model.DateFormat.Equals("dd/MM/yyyy"), new Dictionary<string, object> { { "class", "normalwidth" } })%><label class="displayinline"><%=DateTime.Now.ToString("dd/MM/yyyy")%></label></span>
<span><%= Html.RadioButton("DateFormat", "", new Dictionary<string, object> { { "class", "normalwidth" } })%><label class="displayinline">custom <%= Html.TextBox("customdate", "", new Dictionary<string, object> { { "style", "width:50px; font-size:12px; display:inline;" } }) %> </label></span>

And here is the rendered HTML. Notice each input has the same name, but different values. Only the selected button will have it's value posted back to the server.

    <p><label>Date Format</label> 
        <span><input class="normalwidth" id="DateFormat" name="DateFormat" type="radio" value="MMMM/dd/yy" /><label class="displayinline">October 18, 2009</label></span> 
        <span><input checked="checked" class="normalwidth" id="DateFormat" name="DateFormat" type="radio" value="yyyy/MM/dd" /><label class="displayinline">2009/10/18</label></span> 
        <span><input class="normalwidth" id="DateFormat" name="DateFormat" type="radio" value="dd/MM/yyyy" /><label class="displayinline">18/10/2009</label></span> 
        <span><input class="normalwidth" id="DateFormat" name="DateFormat" type="radio" value="" /><label class="displayinline">custom <input id="customdate" name="customdate" style="width:50px; font-size:12px; display:inline;" type="text" value="" /> </label></span> 
    </p> 

And in your class:

public class Post
{
   public string DateFormat {get; set:}
}

Answer 2

 @Html.RadioButtonFor(m => m.DateFormat, "MMMM/dd/yy")
 @Html.RadioButtonFor(m => m.DateFormat, "yyyy/MM/dd")