How can I access the containing model instance in

问题:

I have the following code in an editor template called DropDown, which I invoke with a UIHint.

if (ViewData.ModelMetadata.AdditionalValues.ContainsKey("TemplateControlParameters"))
{
    var cparms = (Dictionary<string, object>)ViewData.ModelMetadata.AdditionalValues["TemplateControlParameters"];
    var listName = cparms["SelectListName"].ToString();
    list = (SelectList)ViewData[listName];
}

The SelectListName control parameter is supposed to point to a SelectList property of the 'outer' model, i.e. the model that contains the property being edited by this template. However, I can't find a way to reference the containing model instance, only the containing model type. How can I access the instance of the model that this template is being invoked for?

CLOSEST SOLUTION: I have created a derived Controller class that overrides View(string viewName, string masterName, object model) and injects the view model's select list dictionary (IDictionary<string, SelectList>) into the view data:

protected override ViewResult View(string viewName, string masterName, object model)
{
    var result = base.View(viewName, masterName, model);
    if ((model is ViewModelBase) && (!ViewData.ContainsKey(SelectListsViewDataKey)))
    {
        var vm = (ViewModelBase)model;
        result.ViewData.Add(SelectListsViewDataKey, vm.GetSelectLists());
    }
    return result;
}

回答1:

You could get the parent metadata but I don't think that you can get the parent model instance:

@{
    var parentType = ViewData.ModelMetadata.ContainerType;
    var metadata = ModelMetadataProviders.Current.GetMetadataForType(null, parentType);
}