如何在linq或where子句中放置动态列名 [英] How to put dynamic column name in linq or where clause

问题描述

我需要带有动态列的lemda表达式，如下例所示

I need a lemda expression with dynamic column like below example

var item=listItem.Where(DynamicColumn.Contains(textValue));

或

or

var item=listItem.Where(a=>a.DynamicColumn.Contains(textValue));

我尝试了什么：



我试过这样做的方式与我在问题描述，但它不起作用。

What I have tried:

I have tried to do it by the same way i have discussed in the question description but it's not working.

推荐答案

解决方案是动态构建所需的表达式树，通常使用这些LINQ方法为您引导 。



这是一个中等高级的话题，但你不必自己动手：已经有几种解决方案你可以使用：



动态构建Lambda表达式 [ ^ ]

Dynamic Expresso [ ^ ]

运行时的LINQ和动态谓词构建 [ ^ ]

在Linq中动态构建子句 [ ^ ]

<啊ref =https://github.com/kahanu/System.Linq.Dynamic> GitHub - Kahanu / System.Linq.Dynamic：这是.Net 4.0动态语言功能的Microsoft程序集。 [< a href =https://github.com/kahanu/System.Linq.Dynamictarget =_ blanktitle =New Window> ^ ]

The solution is to dynamically build the required expression tree which normally gets done for you "under the hood" by using those LINQ methods.

That's a moderately advanced topic but you don't have to do it yourself: There already are several solutions for this which you could use:

Build Lambda Expressions Dynamically[^]
Dynamic Expresso[^]
LINQ and Dynamic Predicate Construction at Runtime[^]
Build Where Clause Dynamically in Linq[^]
GitHub - kahanu/System.Linq.Dynamic: This is the Microsoft assembly for the .Net 4.0 Dynamic language functionality.[^]

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