Pass values of checkBox to controller action in asp.net mvc4

Question

I want to test if the checkbox is checked or not from my action method. What I need is to pass checkbox value from view to controller.

This is my view:

@using (Html.BeginForm("Index", "Graphe")) {     <table style="width: 100%;" border="1">         <tbody>             <tr>                 <td>Responsable:</td>                 <td>                     <select id="Responsables" name="responsables">                         <option>Selectionnez --</option>                     </select>                 </td>                 <td><input id="responsable" name="checkResp" type="checkbox" /></td>             </tr>             <tr>                  <td><input type="submit" value="Afficher" id="ButtonSubmit"/></td>                 <td><input class="button" id="ButtonReset" type="button" value="Annuler"  /></td>             </tr>         </tbody>     </table> } 

and I try this:

public ActionResult Index(string responsables, bool checkResp) {     Highcharts chart = new Highcharts("chart");      if (responsables != null)     {                   if (checkResp)             chart = Global();         else             chart = Resp(responsables);     }     else         chart = Global();     return View(chart); } 

But I receive this error:

Le dictionnaire de paramètres contient une entrée Null pour le paramètre « checkAct » de type non Nullable « System.Boolean » pour la méthode « System.Web.Mvc.ActionResult Index(System.String, System.String, Boolean) » dans « Project.Controllers.GrapheController ». Un paramètre facultatif doit être un type référence, un type Nullable ou être déclaré en tant que paramètre facultatif. Nom du paramètre : parameters

Translated:

The parameter dictionary contains a null entry for the "checkAct" parameter of non-nullable type "System.Boolean" for the method "System.Web.Mvc.ActionResult Index (System.String, System.String, Boolean) ”in“ Project.Controllers.GrapheController ". An optional parameter must be a reference type, a type Nullable or be declared as an optional parameter. Name of parameter: parameters

Answer 1

If a checkbox is checked, then the postback values will contain a key-value pair of the form [InputName]=[InputValue]

If a checkbox is not checked, then the posted form contains no reference to the checkbox at all.

Knowing this, the following will work:

In the markup code:

<input id="responsable" name="checkResp" value="true" type="checkbox" /> 

And your action method signature:

public ActionResult Index(string responsables, bool checkResp = false) {     //Do Something } 

This will work because when the checkbox is checked, the postback will contain checkResp=true, and if the checkbox is not checked the parameter will default to false.