Asp.net-mvc – MVC Html.CheckBox and form submit issue

asp.net-mvccheckbox

Crazy issue with submitting of values in Html.Checkbox in ASP.NET MVC RC

Some of the values are just not come to Request.Params

At my form I have this line inside the cycle:

<%=Html.CheckBox("cb" + p.Option.Id, p.Option.IsAllowed, new { value = 6 })%>

and it renders to next:

    <input checked="checked" id="cb17" name="cb17" type="checkbox" value="6" />
<input name="cb17" type="hidden" value="false" /> 

    <input checked="checked" id="cb18" name="cb18" type="checkbox" value="6" />
<input name="cb18" type="hidden" value="false" /> 

    <input id="cb19" name="cb19" type="checkbox" value="6" />
<input name="cb19" type="hidden" value="false" />

    <input id="cb20" name="cb20" type="checkbox" value="6" />
<input name="cb20" type="hidden" value="false" />

    <input checked="checked" id="cb21" name="cb21" type="checkbox" value="6" />
<input name="cb21" type="hidden" value="false" />

After submitting the Form I'm get something like:

Form.Params["cb17"] = {6, "false"}
Form.Params["cb18"] = {6, "false"}
Form.Params["cb19"] = {"false"}
Form.Params["cb20"] = {"6,false"}
Form.Params["cb21"] = {"false"}

In the request string Some of the params are displayed twice (normal situation) and some only ONE TIME (only value of hidden field).
It seems that it doesn't rely on whether checkbox was checked or not, whether value has changed or so…

Does anybody faced with such a situation? How can I work around?

Best Answer

   <% using(Html.BeginForm("Retrieve", "Home")) %>//Retrieve is the name of the action while Home is the name of the controller
       <% { %>
    <%foreach (var app in newApps)              { %>  
  <tr> 
       <td><%=Html.CheckBox(""+app.ApplicationId )%></td>      

   </tr>  
<%} %>
 <input type"submit"/>
<% } %>

and in your controller

 List<app>=newApps; //Database bind
 for(int i=0; i<app.Count;i++)
 {

    var checkbox=Request.Form[""+app[i].ApplicationId];
    if(checkbox!="false")// if not false then true,false is returned
 }

the reason you check for false because the Html Checkbox helper does some kind of freaky thing for value true

True returns as:

it makes the string read "true, false"

so you may have thought it was two values but its just one and means true

False returns as:

it makes the string read "false"

Related Solutions

C# – How to handle multiple submit buttons in ASP.NET MVC Framework

Here is a mostly clean attribute-based solution to the multiple submit button issue based heavily on the post and comments from Maarten Balliauw.

[AttributeUsage(AttributeTargets.Method, AllowMultiple = false, Inherited = true)]
public class MultipleButtonAttribute : ActionNameSelectorAttribute
{
    public string Name { get; set; }
    public string Argument { get; set; }

    public override bool IsValidName(ControllerContext controllerContext, string actionName, MethodInfo methodInfo)
    {
        var isValidName = false;
        var keyValue = string.Format("{0}:{1}", Name, Argument);
        var value = controllerContext.Controller.ValueProvider.GetValue(keyValue);

        if (value != null)
        {
            controllerContext.Controller.ControllerContext.RouteData.Values[Name] = Argument;
            isValidName = true;
        }

        return isValidName;
    }
}

razor:

<form action="" method="post">
 <input type="submit" value="Save" name="action:Save" />
 <input type="submit" value="Cancel" name="action:Cancel" />
</form>

and controller:

[HttpPost]
[MultipleButton(Name = "action", Argument = "Save")]
public ActionResult Save(MessageModel mm) { ... }

[HttpPost]
[MultipleButton(Name = "action", Argument = "Cancel")]
public ActionResult Cancel(MessageModel mm) { ... }

Update: Razor pages looks to provide the same functionality out of the box. For new development, it may be preferable.

Asp.net-mvc – Why does the CheckBoxFor render an additional input tag, and how can I get the value using the FormCollection

Have a look here:

http://forums.asp.net/t/1314753.aspx

This isn't a bug, and is in fact the same approach that both Ruby on Rails and MonoRail use.

When you submit a form with a checkbox, the value is only posted if the checkbox is checked. So, if you leave the checkbox unchecked then nothing will be sent to the server when in many situations you would want false to be sent instead. As the hidden input has the same name as the checkbox, then if the checkbox is unchecked you'll still get a 'false' sent to the server.

When the checkbox is checked, the ModelBinder will automatically take care of extracting the 'true' from the 'true,false'

Best Answer

Related Solutions

C# – How to handle multiple submit buttons in ASP.NET MVC Framework

Asp.net-mvc – Why does the CheckBoxFor render an additional input tag, and how can I get the value using the FormCollection

Related Topic