asp.net mvc 3 - IValidatableObject and Nullable value types -

i have struct implements ivalidatableobject, use properties on view model. validation works fine non-nullable properties, if add property of type nullable<mystruct> ivalidatableobject.validate method never called property, if has value.

is there way trigger validation on nullable properties too, or ivalidatableobject not intended used value types?

thanks

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additional information:

i wanted able specify units when entering data in form, e.g. 10m, 100km, 1cm etc. wanted validate entered data within range , of correct format. struct converts string potentially different units (100cm/100m/1km) decimal property has same unit (1/100/1000) , vice-versa.

i used ivalidatableobject validation because validation same instance of mystruct - didn't want add attribute each time used.

my model this:

public class mymodel  {     public mystruct ab {get; set;}     public mystruct? cd {get; set;} } 

my view typed view using model, renders struct text box using display template. when form posted, have custom model binder convert entered string struct.

my controller action looks like:

public actionresult myaction(mymodel model) {     //do stuff } 

the model bound ok properties of type mystruct , nullable<mystruct>.

it seems not possible.

i dug mvc source. in system.web.mvc.dataannotationsmodelvalidatorprovider there following code:

// produce validator if type supports ivalidatableobject if (typeof(ivalidatableobject).isassignablefrom(metadata.modeltype)) {     //stuff } 

according this rejected bug report, nullable<t> cannot assigned interface t implements:

"in short, "datetime?" value can unboxed datetime or iformattable value. cannot assigned datetime or iformattable location."

thus no validators returned.

looks have way.