C# lambda与表达式树

        static void TestExpression() {
 
            Expression<Func<string, string, bool>> expression = (x, y) => x.StartsWith(y);
            Console.WriteLine(expression.Compile()("First","Fir"));

            Console.WriteLine("-----");


            var arg1 = Expression.Parameter(typeof(string), "x");
            var arg2 = Expression.Parameter(typeof(string), "y");
            MethodInfo method = typeof(string).GetMethod("StartsWith", new[] { typeof(string) });
            Expression call = Expression.Call(arg1, method, arg2);
            Console.WriteLine(call);//x.StartsWith(y)
            var lamba = Expression.Lambda<Func<string, string, bool>>(call, new[] { arg1, arg2 });
            Console.WriteLine(lamba);  //(x, y) => x.StartsWith(y)
            var lambaCompiled = lamba.Compile();

            Console.WriteLine(lambaCompiled("First", "Fir"));
            Console.WriteLine(lambaCompiled("First", "Second"));
        }