using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Linq.Expressions;using System.Text;using System.Windows.Forms;namespace WindowsFormsApplication1{    /// <summary>    /// 动态表达式树    /// </summary>    public partial class Form1 : Form    {        class aa        {            public string test            {                get;                set;            }        }        public Form1()        {            InitializeComponent();        }        /// <summary>        /// 示例地址: http://www.cnblogs.com/feichexia/archive/2013/05/28/3104832.html        /// </summary>        /// <param name="sender"></param>        /// <param name="e"></param>        private void button1_Click(object sender, EventArgs e)        {           //A.           //aa a1 = new aa ();           //typeof(aa).GetProperty("test").SetValue(a1, "test2", null);            //B.MessageBox.Show(a1.test);            //ParameterExpression  p1 = Expression.Parameter(typeof(int), "a");            //ParameterExpression p2 = Expression.Parameter(typeof(int), "b") ;            //BinaryExpression binaryExpress = Expression.Multiply(p1, p2);            //var func = Expression.Lambda<Func<int, int, int>>(binaryExpress, new ParameterExpression[] { p1, p2 }).Compile();            //MessageBox.Show(func(10, 20).ToString());            //C. Expression.Property(origParam, prop)            ParameterExpression  p1 = Expression.Parameter(typeof(aa), "a");            var s = typeof(aa).GetProperties();            var s1 = s.ToArray()[0];            MemberExpression member =  Expression.Property(p1, s1.Name) ;            //1           // var fun = (Func<aa, string>)Expression.Lambda(member, p1).Compile();            //or            var fun = Expression.Lambda<Func<aa, string>>(member, p1).Compile();            MessageBox.Show(fun(new aa() { test = "abc" }));            //or            MessageBox.Show(fun.DynamicInvoke(new aa() { test = "abc" }).ToString());        }    }}