Custom model binder for a property

Question

I have the following controller action:

[HttpPost]
public ViewResult DoSomething(MyModel model)
{
    // do something
    return View();
}

Answer 1

@jonathanconway's answer is great, but I would like to add a minor detail.

It's probably better to override the GetPropertyValue method instead of BindProperty in order to give the validation mechanism of the DefaultBinder a chance to work.

protected override object GetPropertyValue(
    ControllerContext controllerContext,
    ModelBindingContext bindingContext,
    PropertyDescriptor propertyDescriptor,
    IModelBinder propertyBinder)
{
    PropertyBinderAttribute propertyBinderAttribute =
        TryFindPropertyBinderAttribute(propertyDescriptor);
    if (propertyBinderAttribute != null)
    {
        propertyBinder = CreateBinder(propertyBinderAttribute);
    }

    return base.GetPropertyValue(
        controllerContext,
        bindingContext,
        propertyDescriptor,
        propertyBinder);
}