如何在LINQ中动态写在哪里? [英] How to write dynamic where in LINQ?

问题描述

我有一个如下的LinQ查询

I have a LinQ query as below

var filtered=from c in country
         where c.Id>=5
         select c;

现在我需要让运算符``> =''是动态的，即运算符可能是``> =''或``==''或``< =''等，具体取决于条件和查询应基于该运算符执行.

Now i need to have the operator ''>='' to be dynamic i.e., the operator may be ''>='' or ''=='' or ''<='' etc depending on a certain criteria and the query should execute based on that operator. How to achieve this in LinQ?

推荐答案

您可以添加一个返回bool的检查功能.
像这样的东西:

Hi,

You could add a check-function which returns a bool.
Something like this:

private bool TestValue(int id, int contiditon)
{
    if (condition == 1)
    {
        return id <= 5;
    }
    else
    {
        return id >= 5;
    }
}

/* your linq query would look like this */
var filtered = from c in country
               where TestValue(c.Id, c.Condition)
               select c;

这是完全未经测试的，因此可能包含错误;)
希望这会有所帮助.

致以诚挚的问候，祝您编程愉快，
停止

This is completely untested so it could contain errors ;)
Hope this helps.

Best regards and happy coding,
Stops

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