c# - Convert Func<TDao, bool> to Func<TEntity, bool> -

given:

class mydao {    public int siteid {get;set;}     public cv3addressdao readsingle(expression<func<cv3addressdao, bool>> predicate)    { //...    } }  class myentity {    public int siteid {get;set;} } 

how can take predicate parameter of type expression<func<mydao, bool>> , convert expression<func<myentity, bool>>?

the type of answer looking for

please note answers must show how conversion works. want implementation similar works :)....

    public mydao readsingle(expression<func<mydao , bool>> predicate)     {         var mappedpredicate = mapfun<mydao , myentity>(predicate);         var result = repository.getsingle<myentity>(mappedpredicate);          return convert(result);//converts entity dao...safe ignore line     }      expression<func<b, bool>> mapfun<a, b>(expression<func<a, bool>> input)     {         expression<func<b, bool>> result = null;//how convert?         return result;     } 

details regarding why want design...

this asp.net mvc 5 application. reason conversion important view not aware of type myentity. in other words if do:

mydaoobject.readsingle<myentity>(myentity => myentity.siteid == "123");

then view layer has reference dll layer because here using myentity. want view layer work dao instead:

mydaoobject.readsingle<mydao>(mydao=> mydao.siteid == "123");

but, have convert dao make useable repository. repository aware of dl objects. trying avoid creating redundant repository support translation. dao contains properties of entity plus some.

i don't have exact code handy, want consume expression provided , perform equivalency conversion yourself.

this stackoverflow question along lines of do.

note p.brian.mackey

the referred answer worked. using jon's answer trick. however, public portion of answer ended being non-visible player func<> conversion. needed was:

    expression<func<b, bool>> mapfun<a, b>(expression<func<a, bool>> input)where : class     {         var result = dbaccesslayer.transformpredicatelambda<a,b>(input);         return result;     } 

note method private. changed public. see @jon answer in answer referenced above full implementation.

public static expression<func<tnewtarget, bool>> transformpredicatelambda<toldtarget, tnewtarget>(expression<func<toldtarget, bool>> predicate)