.net - Specify one parameter for Func at declaration time and another at invoke/execution time -

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from research have not found evidence possible, wondering if there way or next cleanest solution?

i want avoid having pass argument generic function keep clean , improve modularity.

consider following generic looping function invokes predicate function check condition while looping collection:

private sub loopandapplycondition(of t)(byval collection idatacollection, byval condition func(of t, string, boolean), byref result list(of t))   if not collection.activeitems nothing , collection.count > 0     each record in collection    '***    '*** pass in record predicate function here ***    '***         dim meetscondition boolean = condition.invoke(ctype(record, t))         if meetscondition result.add(ctype(record, t))     next   end if end sub

this defines predicate function(condition) , calls generic looping function, has attributename field pass predicate function.

public function alleditablerecords(of t)(byval collection idataobjectcollection, byval attributename string) list(of t)     dim result new list(of t)     '***     '*** pass in attributename field predicate function here ***     '***     dim condition func(of t, string, boolean) = addressof checkifrecordiseditable     loopandapplycondition(of t)(collection, condition, result)   return result end function

this signature of predicate function:

private function checkifrecordiseditable(of t)(record t, attributename string) boolean   'returns conditionresult end function

so summarise, pass in string parameter checkifrecordiseditable via alleditablerecords function , generic record parameter via loopandapplycondition.

i don't think possible, please prove me wrong. i'm happy accept answer in c#, vb.net preferred.

no, not possible define parameters delegates while declaring them.

however, possible encapsulate func , parameters in own class:

public class recordcondition(of t)     public property checkconditionhandler func(of t, string, boolean)     public property attributename string end class

create recordcondition in alleditablerecords:

public function alleditablerecords(of t)(byval collection idataobjectcollection, byval attributename string) list(of t)     dim result new list(of t)      dim recordcondition new recordcondition(of t) {.checkconditionhandler = addressof checkifrecordiseditable, .attributename=attributename}     loopandapplycondition(of t)(collection, recordcondition, result)     return result end function

call checkconditionhandler in loopandapplycondition:

private sub loopandapplycondition(of t)(byval collection idatacollection, byval condition recordcondition(of t), byref result list(of t))     if not collection.activeitems nothing , collection.count > 0         each record in collection             dim meetscondition boolean = condition.checkconditionhandler(record, condition.attributename)              if meetscondition result.add(ctype(record, t))         next     end if end sub

checkifrecordiseditable not change.


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