下面小编就为大家带来一篇浅谈c#表达式树expression简单类型比较demo。小编觉得挺不错的，现在就分享给大家，也给大家做个参考。一起跟随小编过来看看吧
实例如下：
using System;
using System.Linq.Expressions;
class DynamicPredicate
{
public static Expression> Generate(string op)
{
ParameterExpression x = Expression.Parameter(typeof(T), "x");
ParameterExpression y = Expression.Parameter(typeof(T), "y");
return Expression.Lambda>
(
(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(op).Compile();
var floatPredicate = DynamicPredicate.Generate(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(">").Compile()(fA, fB));
Console.ReadLine();
} 
