ConstantExpression exp1 = Expression.Constant(1);構建常量表達式（還可以加類型） BinaryExpression exp12 = Expression.Add(exp1, exp2);構建二元加法表達式，參數為左右兩個需要相加的常量表達式或者變量 ParameterExpression expA = Expression.Parameter(typeof(double), "a");構建參數 ------------------------------------------------------------- ParameterExpression expA = Expression.Parameter(typeof(double), "a"); //參數a MethodCallExpression expCall = Expression.Call(null, typeof(Math).GetMethod("Sin", BindingFlags.Static | BindingFlags.Public), expA); //Math.Sin(a)構建方法調用表達式（表示一次方法調用） --------------------------------------------------- LambdaExpression exp = Expression.Lambda(expCall, expA); //構建lambda表達式（由表達式體和參數構成這個表達式體表示為一個方法調用表達式） --------------------------------------------------- Expression<Func<double, double>> exp = a => Math.Sin(a);構建強類型的表達式樹(表達式樹字面量) ---------------------------------------------------------- UnaryExpression negate= Expression.Negate(left);//構建一元-表達式如：-a ----------------------------------------------------------------------- ConstantExpression strin= Expression.Constant("hello",typeof(string)); NewExpression negate = Expression.New(typeof(StringBuilder).GetConstructor(new Type[] { typeof(String) }), strin); //構造new StringBuilder("hello") ----------------------------------------------------------------------- ParameterExpression a = Expression.Parameter(typeof(int), "a"); ParameterExpression b= Expression.Parameter(typeof(int), "b"); ParameterExpression i= Expression.Parameter(typeof(int), "i"); BinaryExpression add = Expression.Add(a,b); ConstantExpression s=Expression.Constant(1); BinaryExpression substract = Expression.Subtract(i,s); NewArrayExpression arrayint= Expression.NewArrayInit(typeof(int), a, b, add); IndexExpression arracc= Expression.ArrayAccess(arrayint, substract); Console.WriteLine(arracc.ToString()); //new [] {a, b, (a + b)}[(i - 1)]數組訪問 -------------------------------------------------------------------------- MemberExpression mem=Expression.Property(exppro, property)//創建類型的屬性表達式 -------------------------------------- Expression.Equal(left, right)//二元=表達式 ---------------------------------- Expression.GreaterThan(left, right)//二元>表達式 ---------------------------------- Expression.GreaterThanOrEqual(left, right)//>= ------------------------------- Expression.LessThan(left, right)//< --------------------------------- Expression.LessThanOrEqual(left,right)/<= -------------------------------------- return Expression.Call(left, typeof (string).GetMethod("Contains"), right)//like 字符串中包含right表達式代表的字符串 ---------------------------------------------- MethodCallExpression resultExp = Expression.Call( typeof (Enumerable), "Contains", new[] {left.Type}, right, left) //構造in 比如： c=>new[] {"nn","mm"}.contains(c.name) -------------------------------------------- Expression.NotEqual(left, right)//!= ------------------------------------------- Expression.Call(left, typeof (string).GetMethod("StartsWith", new[] {typeof (string)}), right)//left以right字符串開始 ------------------------------------ Expression.Call(left, typeof (string).GetMethod("EndsWith", new[] {typeof (string)}), right)//left以right字符串結尾 --------------------------------------- Expression.AndAlso(left, expression)//and 表達式&& ----------------------------------------- Expression.OrElse(left, orGroupByExpAnd)//or表達式||