asp.net mvc radio button state

Question

I\'m trying out asp.net mvc for a new project, and I ran across something odd. When I use the MVC UI helpers for textboxes, the values get persisted between calls. But, when I

Answer 1

View:

<%=Html.RadioButton("providerType","1")%><label>Hospital</label>
<%=Html.RadioButton("providerType","2")%><label>Facility</label>
<%=Html.RadioButton("providerType","3")%><label>Physician</label>

Controller:

public ActionResult GetType(FormCollection collection)
{
 string type=collection.Get("providerType");

  if(type=="1")
   //code
  else if(type=="2")
   //code
  else
   //code

 return View();
}

Answer 2

I'm using vs2010 now, it works like:

<%=Html.RadioButton("ProviderType","1",Model.ProviderType==1)%><label>Hospital</label> 

looks better?

Answer 3

I've made this HTML Helper extension:

    <Extension()> _
    Public Function RadioButtonList(ByVal helper As HtmlHelper, ByVal name As String, ByVal Items As IEnumerable(Of String)) As String
        Dim selectList = New SelectList(Items)
        Return helper.RadioButtonList(name, selectList)
    End Function

    <Extension()> _
    Public Function RadioButtonList(ByVal helper As HtmlHelper, ByVal Name As String, ByVal Items As IEnumerable(Of SelectListItem)) As String
        Dim sb As New StringBuilder
        sb.Append("<table class=""radiobuttonlist"">")
        For Each item In Items
            sb.AppendFormat("<tr><td><input id=""{0}_{1}"" name=""{0}"" type=""radio"" value=""{1}"" {2} /><label for=""{0}_{1}"" id=""{0}_{1}_Label"">{3}</label></td><tr>", Name, item.Value, If(item.Selected, "selected", ""), item.Text)
        Next
        sb.Append("</table>")
        Return sb.ToString()
    End Function

Then in the view:

<%= Html.RadioButtonList("ProviderType", Model.ProviderTypeSelectList) %>

In the controller the option is mapped automagically using the standard:

UpdateModel(Provider)

Works like a charm. If you are tablephobic, change the markup generated.

Answer 4

The form shouldn't be posting to the querystring, unless you forgot to specify the form as method="POST". How are you specifying the form? Are you using ASP.NET MVC Beta?

Answer 5

If you give the radio buttons the same name as the property on your model, then MVC will automatically set the checked attribute on the appropriate button.

I think this relies on having a strongly typed Model.

Answer 6

What you need is something like this in your view:

<% foreach(var provider in (IEnumerable<Provider>)ViewData["Providers"]) { %>
    <%=Html.RadioButton("ProviderType", provider.ID.ToString(), provider.IsSelected)%><label><%=provider.Name%></label>
<% } %>

And then in your controller have this:

var providers = GetProviders();
int selectedId = (int) Request["ProviderType"]; // TODO: Use Int32.TryParse() instead
foreach(var p in providers)
{
    if (p.ID == selectedId)
    {
        p.IsSelected = true;
        break;
    }
}
ViewData["Providers"] = providers;
return View();

The Provider class will be something like this:

public class Provider
{
    public int ID { get; set; }
    public string Name { get; set; }
    public bool IsSelected { get; set; }
}