c# - Expression Trees with dynamic parameter -

i want convert this:

func<dynamic, object> myfunc = t => return t.name + " " + t.surname; 

into expression tree.

what have came with, this:

parameterexpression target = expressionparameter(typeof(dynamic), "target"); parameterexpression result = expressionparameter(typeof(object), "result"); blockexpression block = expression.block(      new [] { result },      expression.assign(            result,            expression.add(                  expression.add(                       expression.property(target, "name"),                       expression.constant(" ", typeof(string))                  ),                  expression.property(target, "surname")            )      ) ); func<dynamic, object> myfunc = expression.lambda<dynamic, object>>(block, target).compile(); 

however, compiler doesn't typeof(dynamic), , kind of it. dynamic isn't type, object in essence.

so proceeded change parameterexpression:

parameterexpression target = expressionparameter(typeof(object), "target"); 

the code compiles, there problem @ runtime.

i trying value of property name of target, may have sense if object dynamic.

but since target considered of type object, expression throws error telling me name doesn't exist property.

is there expression fetching dynamic property?

for or interested in solution:

parameterexpression target = expression.parameter(typeof(object), "target"); parameterexpression result = expression.parameter(typeof(object), "result");  callsitebinder getname = binder.getmember(    csharpbinderflags.none, "name", typeof(program),    new csharpargumentinfo[] {        csharpargumentinfo.create(csharpargumentinfoflags.none, null)    } );  callsitebinder getsurname= binder.getmember(    csharpbinderflags.none, "surname", typeof(program),    new csharpargumentinfo[] {        csharpargumentinfo.create(csharpargumentinfoflags.none, null)    } );  blockexpression block = expression.block(     new[] { result },     expression.assign(         result,         expression.call(typeof(string).getmethod("concat", new type[] { typeof(object[]) }),                         expression.newarrayinit(typeof(object),                              expression.dynamic(getname, typeof(object), target),                              expression.constant(" ", typeof(object)),                              expression.dynamic(getsurname, typeof(object), target)                         )        )     ) );  func<dynamic, object> myfunc = expression.lambda<func<dynamic, object>>(block, target).compile(); 

here's doing:

1. created callsitebinder obtains value of dynamic property name of dynamic object passed argument
2. created callsitebinder obtains value of dynamic property surname of dynamic object passed argument
3. invoked method string.concat(params object[] args). that, need send arguments array of object. i'm creating array values of getname, " ", , getsurname.

i used following answer guide , reference:

c# 4 “dynamic” in expression trees

with above approach, 1 this:

dynamic person = new expandoobject(); person.name = "matt"; person.surname = "smith";  object value = myfunc(person); console.writeline(value); //will print out "matt smith"  //internally calls: //string.concat(new object[] { person.name, " ", person.surname });