Passing parameters to modelbinder on action parameter

Question

Hi,

I wish to use a modelbinder I've made directly on an action method parameter. Such as:

public ActionResult MyAction([ModelBinder(typeof(MyBinder))] string param1)

However, I need to pass a string into the binder itself, so I was wondering if you could do something along the lines of:

public ActionResult MyAction([MyBinder("mystring")] string param1)

Is it possible?

Answer 1

No, you cannot pass parameters via the attribute declaration. If you look at the source code for ModelBinderAttribute, you will see that its constructor takes only a type argument, that it has no other properties, and that it is a sealed class. So this road is a dead end.

The only way to get information into the ModelBinder that I know of is the FormCollection itself.

You could, however, make a parent binder type and subtype it for each param value which you intend to use. It's messy, but it would work in the example you give.