Question

Ok, I’m an MVC newbie coming from a webforms background, so please excuse any ignorance here. Here is my scenario. I’ve got a table consisting of a list of applications and associated permissions. Each table row consists of 3 pieces of information: a checkbox, some text describing the row, and a dropdown list allowing the user to select the appropriate permission for the application. I want to post this data and only work with the rows in the table which were checked (the id of the row is embedded as the checkbox name). From there, I want to grab the selected value from the DropDownList, and call the necessary code to update the DB. Here is my View page’s code:

            <%foreach (var app in newApps)               { %>                 <tr>                     <td><input type='checkbox' name='AddApps' value='<%=app.ApplicationId %>' /></td>                     <td><%=Html.Encode(app.ApplicationName)%></td>                     <td><%=Html.DropDownList('AppRole', new SelectList(app.Roles, 'RoleId', 'RoleDescription'))%></td>                 </tr>               <%} %> 

How would I retrieve the appropriate values from the FormCollection when I get to the controller on form post? I have done this in the past when I only had checkbox values to retrieve by just calling Request.Form[‘CheckBoxName’] and parsing the string.

Or am I going about this entirely wrong?

Answer 1

You are halfway right in order to post your data that the controller can read the info it must be inside a form as so :

       <% 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>                 <td><%=Html.Encode(app.ApplicationName)%></td>                 <td><%=Html.DropDownList('AppRole', new SelectList(app.Roles, 'RoleId', 'RoleDescription'))%></td>             </tr>           <%} %>        <input type'submit'/>      <% } %> 

and on your controller :

      public ActionResult Retrieve()     {         //since all variables are dynamically bound you must load your DB into strings in a for loop as so:       List<app>=newApps;       for(int i=0; i<app.Count;i++)       {           var checkobx=Request.Form[''+app[i].ApplicationId];         // the reason you check for false because the Html checkbox helper does some kind of freaky thing for value true: it makes the string read 'true, false'           if(checkbox!='false')           {           //etc...almost same for other parameters you want that are in thr form           }         }     //of course return your view     return View('Index');//this vaires by the name of your view ex: if Index.aspx    } 

This site gives more details on how to handle the dropdownlist helper:

http://quickstarts.asp.net/previews/mvc/mvc_HowToRenderFormUsingHtmlHelpers.htm