c# - Nullable DateTimeOffset fromuri parameter in webapi 2 not working -

c# - Nullable DateTimeOffset fromuri parameter in webapi 2 not working -

given action this:

public async task<ihttpactionresult> getstatus(string dataflowid, [fromuri] datetimeoffset? lasttime = null)

and client code uri accessing action:

datetimeoffset? lastly = somedatetime; /* request */ new uri( flow.statusuri + (last.hasvalue? "?lasttime="+last.value.tostring():""));

an exception raized cant convert nullable'1 lasttime.

what needed instead of tostring() on client site webapi 2 able datetime querystring

{"message":"the request invalid.","modelstate":{"lasttime":["the value '1/1/1601 12:00:00 00:00' not valid nullable`1."]}}

using uri.escapedatastring solved issue.

new uri(flow.statusuri + (last.hasvalue? "?lasttime="+uri.escapedatastring(last.value.tostring()):""))

c# asp.net-web-api