Asp.net mvc how to pass multiple checkbox values to controller - asp.net-mvc

Question

Im working on an application which can download emails. In my view if checkbox/checkboxes are checked, i want to pass an ID to controller to download this messages. I will try to explain with code:
#using (Html.BeginForm("DownloadData", "Messages", FormMethod.Post))
{
<table class="table table-bordered table-hover">
#for (int i = 0; i < Model.Count; i++)
{
<tr>
<td><input type="checkbox"
name="selectedIds[#i].messageID"/></td>
<td>#Model[i].messageFrom</td>
<td>#Model[i].messageSubject</td>
<td>#Model[i].messageDate</td>
</tr>
}
</table>
<div class="col-md-offset-2 col-md-10">
<input type="submit" class="btn btn-default" value="Download" />
</div>
}
The #i in name="selectedIds[#i].messageID" doesnt going to be good because its increasing and if i check: 1st the 2nd and the 4th message, it will add only the first two elements to my list.
The controller:
[HttpPost]
public ActionResult DownloadData(List<MessagesModels> selectedIds)
{
return View(...);
}
The model:
public class MessagesModels
{
public int messageID { get; set; }
public string messageSubject { get; set; }
...
}
I think it isnt hard, but cant find the sollution. Thanks for those who can help!

Answer 1

To avoid changing your message model just for this view (or if you are unable to begin with) I would recommend creating a new model for this view to handle selecting like this:
public class MessageSelectionViewModel
{
public MessagesModels Message { get; set; }
public bool IsSelected { get; set; }
}
Your view would now be a list of these new view objects so would look more like this:
<td>#Html.CheckBoxFor(item => item[i].IsSelected)</td>
<td style="display:none;">#Html.HiddenFor(item => item[i].Message.Id)</td>
<td>#Model[i].Message.messageFrom</td>
<td>#Model[i].Message.messageSubject</td>
<td>#Model[i].Message.messageDate</td>
Your post method would become:
[HttpPost]
public ActionResult DownloadData(IEnumerable<MessageSelectionViewModel> selectedMessages)
{
foreach (int messageId in selectedMessages.Where(m => m.IsSelected == true).Select(m => m.Message.Id))
{
}
return View(...);
}
Of course if it's not a big deal you could save some time and effort and just add IsSelected to your model like Stephen suggested.