Question

Simple question. I am trying to create a basic lambda expression that returns the parameter.

(i, o) => o

I have the first part:

ParameterExpression p1 = Expression.Parameter(relationshipItems.ElementType, "i");
ParameterExpression p2 = Expression.Parameter(instanceEntities.ElementType, "o");

And the last part:

LambdaExpression lambda = Expression.Lambda(p2return, p1, p2);

What method do I use to get back the parameter, presumably as a UnaryExpression(p2return)?

Answer 1

Just set the body to be the second parameter, p2. You already have the reference.

var p1 = Expression.Parameter(relationshipItems.ElementType, "i");
var p2 = Expression.Parameter(instanceEntities.ElementType, "o");
var body = p2;
var lambda = Expression.Lambda(body, p1, p2);