public static event Func
     
       myevent;        public delegate void del(int i, int j);        static void Main(string[] args)        {                        var students = new List
      
        {               new Student(){ Id=3, Age=20, Name="张三1", Sex=true   , GradeId=1},              new Student(){ Id=1, Age=22, Name="李四1", Sex= false , GradeId=2},              new Student(){ Id=4, Age=13, Name="王二", Sex= false , GradeId=1},              new Student(){ Id=2, Age=11, Name="赵六", Sex=true   , GradeId=2},                        };            // BookShopPlus2Entities db = new BookShopPlus2Entities();            //AsNoTracking查询的对象不要放在对象池中            //特别说明：对于使用AsNoTracking（）的数据不能用于修改。            //List
       
         db = bsc.Books.AsNoTracking().ToList();            //del mydel = new del(add);            //mydel.Invoke(1, 9);            //// //匿名方法            //mydel += delegate(int h, int m)            //{            //};            ////Lamda表达式            //mydel += (a, b) =>            //{            //    Console.WriteLine(a + b);            //};            //生成 1==1            Expression expwhere = Expression.Equal(Expression.Constant(1), Expression.Constant(1));            //生成 s=>            ParameterExpression exps = Expression.Parameter(typeof(Student), "s");            //生成s.Age>12            Expression exp1 = Expression.GreaterThan(Expression.Property(exps, "Age"), Expression.Constant(12));            //生成s.Age<22            Expression exp2 = Expression.LessThan(Expression.Property(exps, "Age"), Expression.Constant(22));            //生成 s.Age>12 and  s.Age<22  或连接 Expression.Or  and 连接   Expression.And            Expression exp3 = Expression.And(exp1, exp2);                 //Expression
        
         
          > lamband = Expression.Lambda < Func
          
           .Combine(); //生成s=>Age>12 AND s.Age<22 Expression
           
            
             > lamband = Expression.Lambda
             
              
               >(exp3, exps); var s = students.Where(lamband.Compile()).ToList(); } } public class Student { public int Id { get; set; } //学号 public string Name { get; set; } //学员姓名 public int Age { get; set; } //学生年龄 public bool Sex { get; set; } //学生性别 public int GradeId { get; set; } }