我要评论实例如下：
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移动技术网。
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