public class Foo
{
public IList<string> Strings { get; set; }
}
class Program
{
static void Main(string[] args)
{
//Func<Foo, bool> func =
// a => a.Strings.Any(b => b == "asdf");
// b => b == "asdf";
var bParameter = Expression.Parameter(typeof(string), "b");
var asdfConstant = Expression.Constant("asdf");
var compare = Expression.Equal(bParameter, asdfConstant);
var compareExpression = Expression.Lambda<Func<string, bool>>(compare, bParameter);
var ceCompareExpression = Expression.Constant(compareExpression.Compile());
// a => a.Strings.Any(compareExpression)
var parameter = Expression.Parameter(typeof(Foo), "foo");
var foosProperty = Expression.Property(parameter, typeof(Foo).GetProperty("Strings"));
MethodInfo method = typeof(Enumerable).GetMethods().Where(m => m.Name == "Any" && m.GetParameters().Length == 2).Single().MakeGenericMethod(typeof(string));
var anyMethod = Expression.Call(method, foosProperty, ceCompareExpression);
var lambdaExpression = Expression.Lambda<Func<Foo, bool>>(anyMethod, parameter);
// Test.
var foo = new Foo { Strings = new List<string> { "asdf", "fdsas" } };
//Console.WriteLine(string.Format("original func result: {0}", func(foo)));
Console.Write(string.Format("constructed func result: {0}", lambdaExpression.Compile()(foo)));
Console.ReadKey();
}
}