Expression小案例

 

 

 

 

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<br><br><br><br>using System; using System.Collections.Generic; using System.Linq; using System.Linq.Expressions; using System.Text; using System.Threading.Tasks;   namespace _Console {     public static class ExpressionTest     {         //Expression<Func<string, bool>> f = s => s.Length < 5;           public static void Test()         {             ParameterExpression p = Expression.Parameter(typeof(string), "s");               MemberExpression stringLength = Expression.Property(p, "Length");             ConstantExpression five = Expression.Constant(5);               BinaryExpression comparison = Expression.LessThan(stringLength, five);               Expression<Func<string, bool>> lambda = Expression.Lambda<Func<string, bool>>(comparison, p);               //end             /*  将lambda编译为委托             Func<string, bool> runnable = lambda.Compile();               Console.WriteLine(runnable("kangaroo"));             Console.WriteLine(runnable("dog"));             */           }     } }