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 == ).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();
}
}
05-08 08:29