实例如下：
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using System;using System.Linq.Expressions;class DynamicPredicate{ public static Expression<Func<T, T, bool>> Generate<T>(string op) { ParameterExpression x = Expression.Parameter(typeof(T), "x"); ParameterExpression y = Expression.Parameter(typeof(T), "y"); return Expression.Lambda<Func<T, T, bool>> ( (op.Equals(">")) ? Expression.GreaterThan(x, y) : (op.Equals("<")) ? Expression.LessThan(x, y) : (op.Equals(">=")) ? Expression.GreaterThanOrEqual(x, y) : (op.Equals("<=")) ? Expression.LessThanOrEqual(x, y) : (op.Equals("!=")) ? Expression.NotEqual(x, y) : Expression.Equal(x, y), x, y ); }}static void Main() { string op = ">="; var integerPredicate = DynamicPredicate.Generate<int>(op).Compile(); var floatPredicate = DynamicPredicate.Generate<float>(op).Compile(); int iA = 12, iB = 4; Console.WriteLine("{0} {1} {2} : {3}", iA, op, iB, integerPredicate(iA, iB)); float fA = 867.0f, fB = 867.0f; Console.WriteLine("{0} {1} {2} : {3}", fA, op, fB, floatPredicate(fA, fB)); Console.WriteLine("{0} {1} {2} : {3}", fA, ">", fB, DynamicPredicate.Generate<float>(">").Compile()(fA, fB)); Console.ReadLine(); } |
以上这篇浅谈c#表达式树Expression简单类型比较demo就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持服务器之家。
