Converting objects in my MVC3 View

A user can upload a new document and add information, every document has a set of default properties. The admin has the ability to add a small amount of extra properties. He can add a string, bool, datetime value.

When generating my View I get a Dictionary<String,Object> with the extra 开发者_运维知识库properties. In my view I want to generate the right control for the object. So when it's a datetime object I want to load the jquery calendar, boolean a checkbox etc.

@switch (Model.ExtraFields[i].PropertyType)
    {
        case (short)Enums.PropertyType.Boolean:
        @Html.TextBoxFor(model => Convert.ToBoolean(Model.Values[i].ExtraFieldValue))
   break;
        case (short)Enums.PropertyType.DateTime:
        @Html.TextBoxFor(model => Convert.ToDateTime(Model.Values[i].ExtraFieldValue))
   break;
        default:
        @Html.TextBoxFor(model => Model.Values[i].ExtraFieldValue)
        break;
    }

It always gives an error on the Convert.To...

Templates can be used only with field access, property access, single-dimension array index, or single-parameter custom indexer expressions.

Any idea's?

The EditorFor, TextBoxFor and so on all require an expression which gives them access to meta data on the property that you're using. Convert.ToDateTime removes that access (because it returns a value instead) so the methods don't know what property name to use or any additional information like a [Display] attribute. I would suggest you do something like:

@switch (Model.ExtraFields[i].PropertyType) {
    case (short)Enums.PropertyType.Boolean:
        @Html.EditorFor(model => Model.Values[i].ExtraFieldValue, "BooleanEditor")
        break;
    case (short)Enums.PropertyType.DateTime:
        @Html.EditorFor(model => Model.Values[i].ExtraFieldValue, "DateTimeEditor")
        break;
    default:
        @Html.TextBoxFor(model => Model.Values[i].ExtraFieldValue)
        break;
}

Then you create EditorTemplates (as a subdirectory of your controller with specific templates named BooleanEditor.cshtml and so forth like so:

@model object
@Html.CheckBox("", Convert.ToBoolean(Model))

by leaving the first parameter blank you're going to automatically use the property name supplied via the expression from the call to EditorFor.