Building a LINQ expression tree: how to get variable in scope

Question

I\'m building a LINQ expression tree but it won\'t compile because allegedly the local variable $var1 is out of scope:

variable \'\' of t

Answer 1

Your'e adding the Expression.Variable to the list of "normal" expressions in the block - you should use the overload which specifies the variables do declare for the block separately:

Expression finalExpression = Expression.Block(new[] { resultVariable },
                                              expressions);

(And remove the call to expressions.Add(resultVariable);)