[Solved] Help with Inline insert error

[Steve]

Can someone assist in explaining this error or pointing me to a thread where this is explained? When trying to insert a new record using the grid, I get the following error: "No parameterless constructor is defined for this object", Here is my grid code:

<%      = Html.Telerik().Grid(Model.Messages) 
        .Name("Grid").HtmlAttributes(new { style = "width:90%;" }) 
        .DataKeys(k => k.Add(c => c.MessageId))
        .ToolBar(commands => commands.Insert())
        .DataBinding(dataBinding => dataBinding.Server()
                    .Select("Index", "MessageEditor") 
                    .Insert("Insert", "MessageEditor") 
                    .Update("Save", "MessageEditor") 
                    .Delete("Delete", "MessageEditor")) 
        .Columns(columns =>
            {
                columns.Bound(b => b.MessageId).ReadOnly().Visible(false); 
                columns.Bound(b => b.MessageText);
                columns.Bound(b => b.MessageType);
                columns.Bound(b => b.MessageTypeList).Visible(false); 
                columns.Command(commands =>
                            {
                                    commands.Edit();
                                    commands.Delete();
                            }).Width(200);
            })
        .Editable(e => e.Mode(GridEditMode.InLine)) 
        .Sortable()
        .Pageable()
        .Filterable()
%>

[Daniel]

You need to verify if the action on the controller must or not have a parameter.

Example:

public ActionResult Insert(int parameter)
{
}

or

public ActionResult Insert()
{
}

Can you post your "Insert" action?

Daniel.

[Joan Vilariño]

I guess it's more he needs a parameterless constructor for the Messages property class,

[Steve]

This is my Insert method signature:

[GridAction]
[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Insert()
{
    ...
return RedirectToAction("Index");
}

[Daniel]

@Steve.

The [GridAction] is for Ajax Binding only.

For Server Binding only use

[AcceptVerbs(HttpVerbs.Post)]

Can you post the full Insert Action Result?

Daniel.

[Joan Vilariño]

I'll try to explain myself clearer this time. You are specifying a model for the grid the following way:

= Html.Telerik().Grid(Model.Messages)

This implies that the entities for each row of your grid will be items of the "Messages" collection.

The error you are getting is because the class of the items contanined in the "Messages" collection doesn't have a parameterless constructor like this:

public MessagesClass() {
}

When you do an insert, the grid tries to create a new item for the messages class calling it's constructor, and as you don't provide (you really can't) any information on his constructor's parameters, it tries to create the new object calling a parameterless constructor that you don't have... that's why that error.

I've had that error myself in my project, and I'm pretty positive the cause is the one I'm trying to explian to you.

Cheers

[Steve]

Thanks Joan,

I was able to fix the problem. This code was originally written by anotehr developer and your post led me to look at the ViewModel. The ViewModel was not created properly.  When I replaced the ViewModel with my own version everything worked as it should. Thanks for the hint on where to look.

[Joan Vilariño]

You're welcome... I had this problem too with some of my ViewModels